ISO/DIS 15136-3:2026(en)

ISO/TC 67/SC 4/WG 4

Secretariat: ANSI

Date: 2026-01-23

Oil and gas industries including lower carbon energy — Progressing cavity pump systems for artificial lift — Part 3: Downhole-drive systems

© ISO 2026

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Contents

Foreword v

Introduction vi

1 Scope 1

2 Normative references 1

3 Terms and definitions 1

4 Symbols and abbreviations 3

4.1 Abbreviated terms 3

4.2 Symbols 3

5 Functional specification 5

5.1 General 5

5.2 Functional requirements 5

5.2.1 Application parameters 5

5.2.2 Environmental compatibility 6

5.2.3 Compatibility with related well equipment and services 7

5.3 User/purchaser selections 7

5.3.1 General 7

5.3.2 Design validation 8

5.3.3 Functional evaluation 8

5.3.4 Quality control grades 8

5.3.5 Additional documentation 8

6 Technical specification 9

6.1 General 9

6.2 Selection of downhole-drive systems type 9

6.3 Design criteria 10

6.3.1 General 10

6.3.2 Design documentation 10

6.3.3 Materials 10

6.3.4 Dimensional information 11

6.3.5 Design verification 11

6.3.6 Design validation 12

6.3.7 Functional evaluation requirements 12

6.3.8 Design changes 12

6.4 Technical specification— Flexshaft 12

6.4.1 General 12

6.4.2 Technical characteristics for the flexshaft 12

6.4.3 Performance ratings 12

6.4.4 Scaling of design validation 13

6.5 Technical specification— Seal chamber sections 13

6.6 Technical specification— GRU 13

6.6.1 General 13

6.6.2 Technical characteristics for the GRU 13

6.6.3 Performance ratings 13

6.6.4 Scaling of design validation 13

6.7 Technical specification — Three-phase asynchronous motor 13

6.8 Technical specification — PMM 13

6.8.1 General 13

6.8.2 Technical characteristics for the PMM 13

6.8.3 Performance ratings 13

6.8.4 Scaling of design validation 14

7 Supplier's /manufacturer's requirements 14

7.1 General 14

7.2 Documentation information 14

7.2.1 General 14

7.2.2 Delivery documentation 14

7.2.3 Operating manual 14

7.2.4 Product qualification certificate 15

7.2.5 Component data sheet 15

7.3 Permanent component identification 16

7.4 Quality 16

7.4.1 General 16

7.4.2 Quality grade requirements 17

7.5 Raw materials 17

7.6 Traceability 17

7.7 Calibration systems 18

7.8 Examination and inspection 18

7.8.1 General 18

7.8.2 Weld 18

7.8.3 Dimensional inspection 19

7.9 Manufacturing non-conformance 20

7.10 Component functional testing 20

8 Repair 21

9 Shipping, handling, and storage 21

Annex A (informative) User’s/purchaser’s functional specification form 22

Annex B (normative) Design validation rating requirements 24

Annex C (normative) Performance evaluation 35

Annex D (informative) Downhole-drive systems selection 40

Bibliography 42

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon energy, Subcommittee SC 4, Drilling, production and injection equipment.

A list of all parts in the ISO 15136 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

In the field of surface-driven progressing cavity pump lift systems, ISO has published two-part standards:

— ISO 15136-1:2009, Petroleum and natural gas industries — Progressing cavity pump systems for artificial lift — Part 1: Pumps

— ISO 15136-2:2006, Petroleum and natural gas industries — Progressing cavity pump systems for artificial lift — Part 2: Surface-drive systems

With the widespread application of electric submersible progressing cavity pumps (ESPCP) in rodless lift systems, the downhole-drive systems associated with this system can form Part 3 of ISO 15136. Together with Part 1 on progressing cavity pumps, it forms the ESPCP rodless lift system, illustrated in Figure 1. Compared to surface-driven progressing cavity pump lift systems in the first two parts, this system does not require a sucker rod and has no mechanical transmission equipment on the surface. Power is supplied to the downhole-drive systems via power cables to rotate the progressing cavity pump and lift well fluids. This document specifically presents the structures of two types of downhole-drive systems. One is the direct-drive type, as shown in Figure 2a), and the other is the drive type with a gear reducer unit, as shown in Figure 2b).

This part is developed by users/purchasers and suppliers/manufacturers of downhole-drive systems for progressing cavity pumps, intended for use in the petroleum and natural gas industries, including global low-carbon energy applications. ISO 15136-3 provides requirements and information on the selection, manufacture, testing, and usage of downhole-drive systems for progressing cavity pumps as defined within its scope.

Key

1 downhole sensor

2 downhole-drive system

3 progressing cavity pump

4 submersible cable

5 cable clamp

6 tubing

7 junction box

8 electric surface control equipment

Figure 1 — Schematic of electric submersible progressing cavity pump

Key

1 PMM

2 seal chamber section

3 flexshaft

4 three-phase asynchronous motor /PMM

5 seal chamber section

6 GRU

7 flexshaft

Figure 2 — Structures of two types of downhole-drive systems

Oil and gas industries including lower carbon energy — Progressing cavity pump systems for artificial lift — Part 3: Downhole-drive systems

This document specifies design requirements, design verification and validation, quality control, performance evaluation, and maintenance for downhole-drive systems of progressing cavity pumps used in the petroleum, natural gas, and low-carbon energy industries.

This document applies to products meeting the definition of electric downhole-drive systems, including the components that constitute the system: flexshaft, seal chamber section, gear reducer unit, and motor. Components supplied under the requirements of this document exclude previously used subcomponents. This doucument doesn’t apply to the hydraclic downhole-drive systems.

Equipment not covered by this document includes power cables, cable lead seals, cable-specific wellheads, electric surface control equipment s, and junction boxes. Such equipment can be covered in other international standards. This document does not apply to repair and redress equipment requirements.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirement of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 6398‑1:2024, Oil and gas industries including lower carbon energy — Submersible linear motor systems for artificial lift — Part 1: Submersible linear motor

ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel

ISO 10893‑4, Non-destructive testing of steel tubes — Part 4: Liquid penetrant inspection of seamless and welded steel tubes for the detection of surface imperfections

ISO 10893‑5, Non-destructive testing of steel tubes — Part 5: Magnetic particle inspection of seamless and welded ferromagnetic steel tubes for the detection of surface imperfections

ISO 15551:2023, Petroleum and natural gas industries — Drilling and production equipment — Electric submersible pump systems for artificial lift

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

API RP 11S3-1999, Recommended Practice for Electric Submersible Pump Installations

API RP 11S8-2012, Recommended Practice on Electric Submersible System Vibrations

ASTM E94, Standard Guide for Radiographic Examination

ASME BPVC, Section V, Nondestructive Examination

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp

— IEC Electropedia: available at https://www.electropedia.org/

3.1

electric submersible progressing cavity pump

ESPCP

equipment with progressing cavity pump powered by downhole-drive system (3.2) to lift downhole fluids to the surface

Note 1 to entry: The system primarily consists of a downhole-drive systems, a progressing cavity pump, submersible power cable, and a electric surface control equipment.

3.2

downhole-drive system

system installed underground to supply rotational power to the progressing cavity pump

Note 1 to entry: Downhole-drive systems mainly include two types.

Note 2 to entry: Gear-reducer drive consists of a flexshaft (3.3), a seal chamber section (3.4), a GRU (3.5), and a three-phase asynchronous motor (3.6) or permanent magnet motor

Note 3 to entry: Direct drive consists of a flexshaft (3.3), a seal chamber section (3.4), and a submersible permanent magnet motor (3.7).

3.3

flexshaft

Device that connects the progressing cavity pump to the seal chamber section (3.4), aligning the eccentric movement of the pump rotor and ensuring concentric movement with the seal chamber section and motor drive shaft while transmitting torque.

3.4

seal chamber section

component of an ESPCP system that protects the interior of the motor from well fluids and other contaminants, carries the pump thrust, maintains pressure equalization with wellbore fluid pressure and/or transmits the motor torque to the component above it

[SOURCE: ISO 15551:2023, 3.126]

Note 1 to entry: The supporting unit may be required if the expected load is exceeding the thrust rating of the seal chamber

3.5

gear reduction unit

GRU

transmission device that both increases the output torque and reduces the speed of the three-phase asynchronous motor (3.6) or permanent magnet motor (3.7) in order to match the operating speeds and torque of the PCP

3.6

three-phase asynchronous motor

motor powered by an alternating current input, converting electrical energy into mechanical torque via electromagnetic induction

[SOURCE: ISO 15551:2023, 3.71, modified.]

3.7

permanent magnet motor

PMM

type of motor that uses permanent magnet rotor(s) instead of induction rotor(s) as a way to create torque

[SOURCE: ISO 15551:2023, 3.104]

3.8

electric surface control equipment

electric equipment used to control the operation of the ESPCP (3.1) assembly

[SOURCE: ISO 15551:2023, 3.49, modified.]

Note 1 to entry: This electrical equipment is commonly referred to as an adjustable speed drive or switchboard.

3.9

junction box

electrical device installed on the surface, which is used to connect the cable and the electric surface control equipment (3.8)

The user/purchaser shall prepare a functional specification to order products that conform to this document and specify the following requirements and operating conditions as appropriate. This information is used by the supplier/manufacturer to recommend the downhole-drive systems and/or components for the application. These requirements and operating conditions may be conveyed by means of a user’s/purchaser’s functional specification form (Annex A). The user/purchaser shall specify the units of measurement for the data provided.

The downhole-drive systems are designed for specific applications. When used in other applications, re-evaluation is required. The process used for this re-evaluation shall be no less stringent or documented than that required for the initial application, and shall be subject to approval.

The user/purchaser shall specify in the functional specification, whether the supplier/manufacturer technical specification response is based on supply of component(s) only or on component(s) and assembled system(s).

General

While installed, the ESPCP system shall perform in accordance with its functional requirements, which are typically determined based on application parameters. These parameters include, but are not limited to, those listed in 5.2.1.2 to 5.2.1.4, as applicable.

Well information

The following well information should be specified, as applicable:

a) geographical location;

b) operating environment, such as heavy, shale and conventional oil production, coal bed methane applications(deliquification) and source water production;

c) well type, such as vertical, slant, deviated or horizontal;

d) wellhead location, such as onshore, platform or subsea;

e) reservoir type, such as carbonate, consolidated sandstone, unconsolidated sandstone, coal or shale;

f) reservoir recovery mechanism or process, such as aquifer drive, solution gas drive, water flood, thermal or coal dewatering;

g) enhanced oil recovery, such as CO2 flood, water-alternating-gas or polymer flood;

h) existing or planned power supply details, such as generator/utility, volts, frequency, kVA/Amp supply limitations;

i) existing or planned surface equipment details, such as switchboard, space restrictions.

Completion information

The following completion information should be specified, as applicable:

a) completion type, such as perforated casing or open hole;

b) completion diagram

c) proposed pump setting depth in terms of MD and TVD of the pump intake;

d) existing or planned total well depth, such as plug back depth in terms of MD and TVD;

e) depth of producing/perforation interval(s), top and bottom, in terms of MD and TVD;

f) casing/liner size including outside diameter and weight, connection type and grade of production casing;

g) production tubing size(s) including outside diameter, mass (weight), connection type, and grade;

h) production tubing inner coating type and thickness;

i) well deviation survey; or, if not provided, as a minimum:

— inclination and estimated dogleg severity at pump setting depth;

— maximum dogleg severity between wellhead and pump setting depth for each casing or liner segment that the ESPCP has to pass through during installation;

j) sand control measures, such as none, slotted liner, gravel pack or sand screen;

k) other well dimensions that can restrict the ESPCP installation or operation.

Operating and production information

The following operating and production information should be specified, as applicable:

a) expected daily production rate;

b) water cut;

c) dynamic fluid level;

d) flowing bottom-hole pressure;

e) tubing head flowing pressure;

f) casing head pressure;

g) static temperature at a reference depth;

h) flowing temperature at a reference depth;

i) minimum expected bottom-hole temperature;

j) maximum expected bottom-hole temperature.

k) wellhead flowing fluid temperature;

l) total producing gas-oil-ratio;

m) special operational conditions, such as unloading heavy completion fluids, sand face control limitations, delayed start-up, unusual anticipated duty cycles (stops and starts);

n) slugging tendency, such as gas, water, solids or steam.

The user/purchaser shall specify the environmental compatibility requirements. The following parameters should be supplied, as applicable:

a) for oil:

1) density at standard temperature and pressure or API gravity;

2) compositional analysis, including, but not limited to

i) type and concentration of aromatic species;

ii) aniline point.

3) viscosity at standard conditions;

4) bubble point pressure at reservoir temperature;

5) solution gas-oil-ratio;

b) for water:

1) pH;

2) density;

3) chloride concentration/salinity;

4) other corrosives, if applicable;

c) for gas:

1) composition, such as:

i) CO₂ concentration (mole percentage);

ii) H₂S concentration (mole percentage);

2) specific gravity.

d) for solids:

1) history of solids related problems (e.g. erosion, plugging, wear);

2) erosional velocity limit, if known;

3) morphology, such as size, structure, angularity, composition;

4) if sand control system is present, expected particle size distribution that will be present in production fluid;

5) scale deposition tendency;

6) asphaltene deposition tendency;

7) paraffin deposition tendency.

e) other:

1) emulsion properties, such as:

i) inversion point data (percentage water cut);

ii) emulsion viscosity at downhole operating conditions over predicted pump life;

iii) emulsion forming tendency;

2) foamy oil behaviour, such as that affecting annular fluid level;

3) other fluid types and concentrations, such as diluent, corrosion/scale inhibitor, completion fluid, dispersants and injection points in the wellbore.

The user/purchaser shall specify related well equipment and service considerations that can impact the compatibility of the proposed component for the well such as material requirements, dimensional limitations, transportation, and installation restrictions, to ensure that the component conforms to the intended application:

a) wellbore condition (casing scaling, corrosion, wax buildup, sand production, downhole fish and presence of packers, etc.);

b) size, type and configuration of other products used with or in conjunction with this product (progressing cavity pumps, tubing, scale preventer, gas separators and downhole sensors, etc.);

c) Dimensions, structural types, and material requirements for the product's interface with the submersible power cable;

d) Well site equipment that may affect the transportation, installation, operation, maintenance, or relocation of this product.

e) areas with special environmental or safety concerns.

Table 1 provides the compiled list of the selection criteria for downhole-drive systems’ components that shall be selected by the user/purchaser. The grades can vary by component as selected by the user/purchaser. Guidelines on the selections available is provided in 5.3.2, 5.3.3, and 5.3.4.

Table 1 — User/purchaser grade selections

This document provides three design validation grades for each component as indicated in Table B.1, of which one shall be selected by the user/purchaser:

— V1: highest grade;

— V2: intermediate grade;

— V3: basic grade.

This document provides three functional evaluation grades for each component as indicated in Table C.1, noting that some components can have fewer:

— F1: highest level of functional evaluation;

— F2: intermediate level of functional evaluation;

— F3: basic level of functional evaluation.

The user/purchaser shall specify the following two quality grades, which are detailed in Clause 7:

— Q1: high level of quality control;

— Q2: intermediate level of quality control;

— Q3: basic level of quality control.

Additional documentation, such as operator's manuals, certificate of compliance and/or product data sheet, above that required for a specific quality grade may be requested by the user/purchaser.

The supplier/manufacturer shall prepare a technical specification, which responds to the requirements in the functional specification set forth by the user/purchaser or which identifies in detail where variance(s) to the requirements in the functional specification exist or are offered.

The technical specification comprises three classes of information relating to obligation for disclosure of these documents by the supplier/manufacturer to the user/purchaser:

— Public information: this information should be identified as such and provided without restrictions (e.g. an ASTM material specification and published performance curves).

— Confidential information: this information should be identified as such (e.g. an engineering drawing) and may be either provided or made available for inspection.

— Trade secrets: this information should be identified as such (e.g. a secret formula or process), in which there is no obligation to disclose it to the user/purchaser.

The timing of disclosure may be governed by agreement between the supplier/manufacturer and the user/purchaser, considering the development time required. The documentation and disclosure requirements of this clause are separate from the requirements of other (sub)clauses, e.g. 7.2.

Where a covered component or system includes a non-covered component, the inclusion of the non-covered component shall not cause the specified requirements or performance ratings of the component or systems as established under this document to be invalidated. The evidence supporting this shall be documented by the supplier/manufacturer. Components or systems not covered in this document can be addressed in other national or international standards.

This document is not intended to inhibit a supplier/manufacturer from offering, or the user/purchaser from accepting, alternative equipment or engineering solutions. This can be particularly applicable where there is innovative or developing technology. Where an alternative is offered, the supplier/ manufacturer shall clearly and completely identify any variations from the requirements of this document.

The Supplier/manufacturer shall recommend the type of downhole-drive systems based on the application parameters provided by the user/purchaser in 5.2 See the recommended method for the type selection in Annex D.

The following data shall also be provided, along with units:

a) speed range, r/min;

b) maximum working torque, N∙m or in∙lb;

c) axial load capacity (relationship between load and expected life);

d) product dimensions and weight;

e) gear ratio if a GRU type is selected;

f) operating temperature range,;

g) the temperature rating of the components;

h) response to special requirements provided by users/purchasers in Clause 5.

The supplier/manufacturer shall conform to the functional specification when designing the component conforming to the technical specifications. Manufacturing requirements are detailed in Clause 7.

Documentation during the design process for each type, size, and model of component shall at least include:

a) design criteria with references to the essential variables considered when designing the component conforming to the requirements of the technical specifications and functional requirements;

b) engineering drawings and material lists;

c) applicable specifications and standards;

d) validation testing procedures, acceptance criteria, and approved results (see Annex B);

e) design verification and acceptance criteria;

f) published performance curves, where applicable;

g) design changes and justification for those changes.

General

Metallic and non-metallic materials shall be specified by the supplier/manufacturer and shall be appropriate for the requirements in the functional specification. The supplier/manufacturer shall have documented specifications for all materials in critical subcomponents. All materials used shall conform with these specifications.

Metallic materials such as flexshaft, GRU and motor of downhole-drive systems shall be as specified in this document; non-metallic materials can be implemented according to other relevant documents. All materials shall be specified by the suppliers/manufacturers and shall be appropriate for the requirements in the functional specification.

As an exception, material substitutions in validated equipment designs are allowed without validation testing, provided that the change in material does not constitute a substantive design change and that the supplier/manufacturer’s material selection criteria are documented and approved by a qualified person and meet all other requirements of this document.

The supplier's/manufacturer’s specifications shall define for metallic materials (if applicable):

a) chemical composition according to an applicable standard or to a supplier's/manufacturer's internal specification;

b) mechanical property limits, to include as a minimum:

1) tensile strength;

2) yield strength;

3) hardness;

4) residual stress;

5) bending strength

6) fatigue life

c) electrical properties:

1) resistivity or conductivity;

2) insulating property;

3) high temperature resistance.

d) magnetic properties:

1) magnetic permeability;

2) core loss.

Welds

Welds shall be specified appropriate to the material, function, and service of the component and/or assembly; and weld identification and examination shall be in accordance with the specified quality grade. Requirements shall be in accordance with the supplier’s/manufacturer’s specifications as defined in 7.9.2.

Coatings or surface treatments

Coatings or surface treatments shall be in response to the operating environment specified in the functional requirements (see 5.2.2). Coatings and surface treatments addressed by this subclause are limited to those that provide performance enhancements for erosion, anti-friction and corrosion of subcomponent materials, which are designed to be in direct contact with production fluids as specified in the design basis. The supplier's/manufacturer’s specifications shall specify, where applicable, the characteristics and acceptance criteria of the coatings or surface treatments including but not limited to:

a) basic coating type and surface treatment composition;

b) corrosion and /or chemical resistance;

c) effective surface hardness;

d) minimum and maximum coating thickness;

e) roughness;

f) application process;

g) bond strength;

h) coupon testing;

i) defect criteria, e.g. holidays.

Dimensional information for the downhole-drive systems shall be provided to analyze and calculate equipment will pass within the wellbore. The supplier/manufacturer shall specify:

a) maximum component OD;

b) component mass (weight) and length as installed and shipped;

c) schematic diagram of components including dimension information for external fittings.

Design verification shall be performed by the supplier/manufacturer to verify that the product design conforms to the supplier's/manufacturer's design basis. Design verification activities are conducted to ensure that the design outputs meet the design basis input requirements. Design verification includes documented activities, such as review of design calculations, product testing and comparison with similar designs and historical records of defined operating conditions. Empirical methods and/or physical testing used in design verification shall be fully documented and supported with drawings and material specifications. All design verification documentation shall be included in the product design file and shall be approved by a qualified person other than the design's originator.

Design validation testing shall be performed to verify that the component design conforms to the component performance rating as per Annex B. Design validation activities are conducted to ensure the component performance meets the intended application or use as defined by the supplier's/ manufacturer's design basis. The design validation grade specifies the process of proving a design by testing to demonstrate conformity of the product to design requirements for each validation grade per Annex B, which provides a detailed description of the three validation grades (V1, V2 and V3) and includes the schematic diagram of functional test device for reference in this document.

Functional evaluations shall be performed in accordance with Annex C and shall be approved by a qualified person to verify that each component manufactured meets supplier's/manufacturer’s documented requirements, technical specification and the functional specification. The evaluation results shall be documented and shall become a portion of the quality documentation for that component.

All design changes shall be documented and reviewed against design verification and validation to determine if they constitute a substantive design change. A substantive design change refers to a modification determined by the supplier/manufacturer to impact the product’s intended use conditions. A design that undergoes substantive changes is considered a new design and shall be verified as specified in 6.3.5 and validated as specified in 6.3.6.

Changes to a component identified as a substantive design change require design validation. Design change(s) shall be validated and verified through the same methods utilized for the original component or subcomponent. Where testing is performed on subcomponent(s), the test(s) shall simulate the design criteria conditions of the component at its rated limits. The supplier/manufacturer shall document the detailed test results and analysis that demonstrate that the component or subcomponent(s) test adequately simulates the required range of design criteria conditions.

The supplier/manufacturer shall prepare the technical specification for the flexshaft that responds to the functional requirements. The supplier/manufacturer shall provide to the user/ purchaser the component data as defined in 7.2.

The flexshaft shall serve as a connection between the top of the seal chamber section and the bottom of the PCP section.

The supplier/manufacturer shall provide the following performance characteristics in accordance with Annex B:

a) two axes relative displacement;

b) static load;

c) static overload;

d) dynamic load.

Scaling of design for flexshaft is not allowed.

The supplier/manufacturer shall prepare the technical specification for the seal chamber sections that responds to the functional requirements. The supplier/manufacturer shall provide to the user/ purchaser the component data as defined in 7.2.

Technical specifications for seal chamber section are detailed in ISO 15551:2023, 6.8.3. The testing should be done at PCP speed, 0rpm~ 500 rpm. The oil specification for seal chamber sections should be matched in terms of viscosity, viscosity-temperature characteristics, anti-wear properties and insulation properties according to the load, temperature and friction characteristics.

The supplier/manufacturer shall prepare the technical specification for the GRU that responds to the functional requirements. The supplier/manufacturer shall provide to the user/ purchaser the component data as defined in 7.2.

The GRU is the transmission device that increases output torque by adjusting the speed of the three-phase asynchronous motor while reducing the asynchronous speed of the submersible motor to a speed acceptable for the PCP.

The supplier/manufacturer shall provide the following performance characteristics in accordance with Annex B:

a) reduction ratio;

b) transmission efficiency.

Scaling of design for GRU is not allowed.

Technical specifications for three-phase asynchronous motor are detailed in ISO 15551:2023, 6.9.3.

The supplier/manufacturer shall prepare the technical specification for the PMM that responds to the functional requirements. The supplier/manufacturer shall provide to the user/ purchaser the component data as defined in 7.2.

The PMM shall convert input electrical power to the required torque needed to rotate all coupled ESPCP components at the required design frequency.

The supplier/manufacturer shall provide the following performance characteristics in accordance with Annex B:

a) no-load operating current;

b) no-load back electromotive force;

c) motor efficiency;

d) power factor;

e) winding temperature rise.

Scaling of design for PMM is not allowed.

This clause contains the detailed requirements to verify that each component manufactured meets the requirements of the technical specifications. Design validation performance rating requirements are addressed in Annex B.

The supplier/manufacturer shall establish and maintain documented information that supports compliance with this document's requirements. Documentation shall be retained as evidence of compliance, in a clear and legible format. It may use any storage method, such as hard drives. Information shall be categorized for easy replacement and stored in a suitable environment to prevent damage or loss.

All documentation shall be available for the user's or the purchaser's access and review within 14 days of the request. For sensitive or proprietary documents, suppliers/manufacturers may limit access to visual, controlled inspections.

Design documentation (see 6.3.2), data, and component data sheet(s) shall be retained for 10 years after the last manufacture date of the component. The records of delivery and manufacturing shall be retained for 5 years from the dates of delivery and manufacturing, respectively.

Documentation to be provided with each component delivered to the user/purchaser shall at least include:

a) identification by component, including ancillary equipment;

b) name and address of supplier/manufacturer;

c) dimensions and weights of each component;

d) design validation grade;

e) functional evaluation documentation according to the specified functional grade;

f) quality documentation according to specified quality grade;

g) component internal fluids used, such as three-phase asynchronous motor fluid, PMM fluid.

h) electrical nameplate information.

When required by 5.3.4, the operator’s manual shall be supplied. The operator's manual shall contain the following information:

a) manual version number;

b) product illustrations identifying main downhole-drive systems components and key dimensions;

c) transport and storage guidelines;

d) installation and removal guidelines;

e) operation and troubleshooting instructions, including safety and environmental precautions for acceptable operations;

f) maintenance guidelines;

g) safety instructions should include anti-reverse functionality of control system to prevent injury due to motor backspin and high voltage generation during downhole-drive systems running in hole and pulling out of hole or during unexpected power loss in production.

NOTE API RP 11S9 Annex G provides additional functionalities for reference.

When required by the quality grade or the user/purchaser, certificates of conformance shall be supplied. The certificate of conformance shall state that the component meets the following requirements:

a) design validation grade;

b) functional evaluation grade;

c) quality control grade.

The statement shall include the component identification and shall be approved by the supplier's/ manufacturer’s designated qualified person.

General

When required by the quality grade or the user/purchaser, a component data sheet shall be supplied. The component data sheet shall contain the information as specified in 7.2.5.2 for all components and additional information as specified in 7.2.5.3 to 7.2.5.7, where applicable.

All components

The supplier/manufacturer shall provide the following information for all components:

a) quality grade;

b) design validation grade, where applicable;

c) functional evaluation grade, where applicable;

d) dimensions and weights, installed;

e) connection type, such as thread type, flange type, where applicable;

f) materials for housings, shafts seals and fasteners, where applicable;

g) external coating types used, where applicable;

h) maximum operating temperature rating, where applicable;

i) shipping, handling and storage requirements for appropriate storage environmental conditions and duration.

Flexshaft

The supplier/manufacturer shall provide the following information for the flexshaft to be supplied:

a) torque limitations;

b) axial load;

c) two axes relative displacement.

Seal chamber sections

The supplier/manufacturer shall provide the information as defined in ISO 15551:2023 7.2.5.7 for the seal chamber sections.

GRU

The supplier/manufacturer shall provide the following information for the GRU to be supplied:

a) reduction ratio;

b) transmission efficiency.

Three-phase asynchronous motor

The supplier/manufacturer shall provide the information as defined in ISO 15551:2023 7.2.5.8 for the three-phase asynchronous motor.

PMM

The supplier/manufacturer shall provide the following information for the PMM to be supplied:

a) no-load operating current;

b) no-load back electromotive force;

c) motor efficiency;

d) power factor;

e) winding temperature rise;

f) rated power;

g) rated voltage;

h) rated current;

i) rated torque;

j) speed range;

k) connection type to the motor lead extension cable, such as tape-in or plug-in.

Each component shall be permanently marked with the component’s unique identifier, e.g. serial number. Components manufactured with “re-certified” subcomponents shall be permanently marked with a unique identifier included as part of the component serial number.

The supplier/manufacturer shall have documented quality control procedures implemented by qualified personnel to ensure that each component supplied/manufactured complies with the supplier's/manufacturer’s applicable specifications drawings, procedures and standards. This requirement is also applicable to all sub-suppliers to the supplier/manufacturer. This requirement is applicable to any component or subcomponent that meets the requirements of this document.

Each supplier of components used in the downhole-drive systems shall implement a quality system to verify that each component meets the specified requirements. The supplier/manufacturer shall document and provide evidence of compliance with the component requirements in accordance with the selected quality grade. Component validation records shall conform to the supplier’s/manufacturer’s data control.

The requirements defined in Table 2 shall be implemented in accordance with the referenced subclauses. Table 2 specifies the percentage of components in each purchase order that must be inspected with a minimum of 1. If the percentage of subcomponents inspected is less than 100 %, the supplier/manufacturer shall use a documented method to determine the sample size.

For Table 2, subcomponent by specified sample size refers to the percentage of subcomponents to be inspected per heat or batch lot with a minimum of 1. If the percentage of subcomponents inspected is less than 100 %, the supplier/manufacturer shall use a documented method to determine the sample size.

Testing methods specified in Table 2 are requirements to meet the quality grade. Conformance to the requirements of a higher quality grade automatically qualifies the final component for lower grades. These procedures include acceptance criteria for all manufactured components furnished to this document.

Table 2 — Quality grade requirements for downhole-drive systems

When required by the quality grade or when specifically requested by the user/purchaser, raw material used in the manufacture of components and subcomponents shall have a material certification report to verify conformance to the chemistries and properties as stated in the supplier's/manufacturer’s documented material specifications. All materials shall be provided by audited and approved material suppliers. Material certifications are not required for common hardware or shipping hardware.

Traceability shall be in accordance with the supplier’s/manufacturers’ documented procedures. All components shall be traceable to their raw material heat(s) or batch lot(s) and material test report using a unique identifier. Traceability of equipment is considered sufficient if the equipment meets the requirements of this document when it leaves the supplier’s/manufacturer’s inventory.

For Q2 quality grade, traceability shall be in accordance with supplier's/manufacturer’s documented procedures. For Q1 quality grade, all subcomponents with the exception of common hardware, process materials (such as penetrants, solvents) and shipping hardware shall be traceable to their raw material heat(s) or batch lot(s) and shall have a unique identifier. The unique identification of components shall allow for traceability of the component to the point that it is installed into the finished component. Traceability of equipment is considered sufficient if the equipment meets the requirements of this document when it leaves the supplier’s/manufacturer's inventory.

Inspection, measuring and testing equipment used for acceptance shall be used only within its calibrated range and shall be identified, controlled, calibrated and adjusted at specific intervals in accordance with the manufacturer's procedures, not to exceed one year. The supplier's/manufacturer’s procedures shall be based on ISO/IEC 17025. See also ANSI/NCSL Z540.3.

Technologies for inspection, measuring and testing with verifiable accuracies equal to or better than those listed in this document may be applied with appropriate documentation and when approved by qualified personnel.

Calibration intervals shall be established based on repeatability and degree of usage. Intervals may be lengthened or shortened based on documented repeatability, amount of usage and calibration history, but the interval shall not exceed one year.

The ranges, calibrations, resolutions, reading capabilities, time-based increments and recording capabilities shall have a confirmed accuracy that allows each parameter used for acceptance to be measured to a level of accuracy that assures the conformance to the specified acceptance criteria. Each measured parameter shall be documented as directly as practical from the subcomponent, component or assembly under test. All measuring and instrumentation systems shall be calibrated as a fully operational system and shall be used only within their calibrated ranges that facilitate repeatable readings by a qualified person.

When specified by the supplier/manufacturer or user/purchaser, NDE and inspections shall be performed and accepted according to the supplier’s/manufacturer’s documented specifications. The supplier’s/manufacturer’s documented specifications shall include the requirements specified in this subclause and acceptance criteria.

NDE instructions shall be detailed within the supplier's/manufacturer's documented procedures and conform with this document. All NDE instructions shall be approved by a qualified ISO 9712 Level III examiner and performed by a qualified person. Personnel performing and accepting NDE shall be qualified in accordance with the supplier’s/manufacturer’s procedures as a minimum for evaluation and interpretation. Personnel performing visual examination shall have an annual eye examination in accordance with ISO 9712, as applicable to the discipline to be performed. As an alternative, the quality manager shall be authorized to qualify quality inspector’s reading/observation capabilities based on pre-specified criteria (such as eye examination chart readings from a specified distance).

The inspection results shall be documented.

General

Weld inspections shall be performed as specified by the quality grade and according to the requirements of this subclause.

Visual inspection

A visual inspection of all visible welds shall be conducted and recorded in accordance with the quality grade. The following features shall be considered unacceptable during the visual inspection of welds:

a) cracks in the base or filler metal;

b) inclusions;

c) surface defects.

The implementation of visual inspection requires documented procedures that include specific acceptance criteria and with approved and documented results. Visual inspection requires that 100 % of the accessible/visible surfaces to be inspected.

Radiographic examination

Radiographic inspections shall meet the requirements of ASTM E94.

Ultrasonic examination

Ultrasonic testing shall meet the requirements of ASME BPVC, Section V, Article 5.

Magnetic particle inspection

Magnetic particle inspections shall be in accordance with ISO 10893-5 or ASTM E709.

Liquid penetrant inspection

Liquid penetrant inspection shall be in accordance with ISO 10893-4 or ASTM E165.

Gas penetrant inspection

Gas penetrant inspections shall meet the requirements of ASME BPVC, Section V, Article 5.

General

The downhole-drive systems shall be dimensionally inspected in accordance with the quality grade to assure conformance with the supplier's/manufacturer’s design criteria and specifications.

Critical dimensional inspection

This subclause addresses the minimum required characteristics of critical dimensional inspections to aid the supplier/manufacturer and user/purchaser in making decisions. Critical dimensional inspections shall include those features necessary for reliable function of the equipment and will be documented by the supplier/manufacturer using documented procedures and approved by a qualified person.

Critical dimensional inspections shall at least include the following:

a) shaft straightness;

b) stator bore minimum drift diameter;

c) rotor OD/ID;

d) alignment fit dimensions controlling mating and moving parts;

e) dimensions associated with rotating clearances, such as bearings;

f) length dimensions controlling stack up tolerances;

g) o-ring groove diameters;

h) surface finish for sealing surfaces;

i) external diameters, when critical for the application;

j) keyways and splines (via gages);

k) housing and barstock threads required for sealing and/or alignment;

l) maximum OD of the downhole-drive systems;

m) total length of downhole-drive systems;

n) dimensions of external connectors.

The supplier/manufacturer shall establish and maintain documented procedures to ensure that a component or subcomponent that does not conform to specified requirements is prevented from being delivered or installed. This control shall provide for the identification, segregation, evaluation, documentation and disposition of a non-conforming component or subcomponent.

Non-conforming components or subcomponents dispositioned for rework shall be reinspected to the same requirements as the original component or subcomponent. Non-conforming components or subcomponents dispositioned for use as-is are acceptable for Q2 quality grade provided that the dispositioned component or subcomponent is evaluated and approved by a qualified supplier/manufacturer person. For Q1, use as-is also requires approval of a qualified user/purchaser person. Responsibility for review and authority for disposition of non-conforming components and subcomponents shall be specified by the supplier's/manufacturer’s documented procedures.

Functional evaluation testing shall be successfully performed by the supplier/manufacturer on each component manufactured in accordance with this document. Test results shall be documented, dated, and signed by qualified personnel performing the test. The testing details and acceptance criteria shall be specified by the supplier’s/manufacturer’s documented procedures. Functional evaluation testing shall conform to requirements of Annex C.

Repairs to downhole-drive systems shall return the product to a condition meeting the requirements stated in this document at the time of its original manufacture. Each repaired/redress product shall undergo effectiveness testing in accordance with the requirements of this document prior to shipment.

Each repaired/redress product shall be permanently identifiable. Identification marks shall include the repair/redress centre, date of repair, and traceable test records. Manufacturers shall maintain documented records of the repair/redress details and traceability.

Components shall be handled, stored and shipped according to the documented processes and specifications of the supplier/manufacturer to prevent deterioration. Components shall be packaged for transport according to supplier's /manufacturer's documented specifications to prevent damage from normal handling and contamination. All material provided for transport shall be clearly identified for removal prior to use. API RP 11S3 provides guidelines for appropriate practices of component handling.

Components shall be stored in conformance with the guidelines provided in the component data sheet to prevent damage or deterioration under environmental conditions specified in the functional requirements.

For components that have been stored for prolonged periods, or that have been stored under environmental conditions that are outside those specified in the user functional requirements, the user/purchaser shall consult with the supplier/manufacturer to determine the shelf life of the components.

1. 
   (informative)
   
   User’s/purchaser’s functional specification form

Table A.1 can be used by the user/purchaser to assist in specifying the functional requirements of the downhole-drive system as required in Clause 5. This form is not necessarily inclusive of all requirements.

Table A.1 — User’s/purchaser’s functional specification form

1. 
   (normative)
   
   Design validation rating requirements
   1. General

This annex specifies the design validation rating requirements, which include multiple individual validation procedure(s), process(es) and test(s). and provides the supplier/manufacturer requirements for establishing the performance ratings as defined in Clause 6. The supplier/manufacturer shall document the validation test procedures and results in a design validation file conforming to the requirements of 7.2. The design validation file shall contain test results that validate the design and shall be reviewed and approved by a qualified person other than the originator. This review shall confirm that, as a minimum, all of the design validation requirements of this document have been met. All testing shall be performed to conform to the requirements of Clause 7 and the document procedures that include acceptance criteria with the results approved by a qualified person.

Ratings shall be established at performance identified during the validation testing process.

NOTE Results from design validation testing are not necessarily directly applicable for prediction of downhole performance during operation.

• 1. Design validation grades

This document provides three grades of design validation for the components of the downhole-drive systems:

— V1: Highest grade – satisfies the applicable functional, technical and manufacturing requirements of this document. The V1 design validation file shall include all of the design validation requirements used to validate the design methods, calculations and test results.

— V2: Intermediate grade – satisfies the applicable functional, technical and manufacturing requirements of this document. The V2 design validation file shall include all of the design validation requirements used to validate the design methods, calculations and test results. Validation grade V2 is a designation provided to accommodate use of the supplier's/manufacturer's existing and established design validation practices and documentation of performance to ensure all the components satisfies the requirements of this document.

— V3: Basic grade – satisfies the applicable functional, technical and manufacturing requirements of this document. The V3 design validation file has no specific requirements of the design validation requirements, methods, calculations and test results. Validation grade V3 is a designation provided to accommodate that documentation of design validation of the applicable component may be determined from previously documented experience gained from manufacture of a component and/or internal design basis documentation. For validation grade V3, it is expected that existing information in the design validation file will be made available to satisfy the requirements of this document.

Components qualified to higher grades of design validation shall be considered qualified for lower grades of design validation. Components provided as V2 shall additionally conform to 6.3.8(design changes). Table B.1 lists the specific requirements for each design validation grade of the components.

Table B.1 — Design validation grade requirements

• 1. Method for determining performance ratings
     1. For all components

The supplier/manufacturer shall specify the shaft power rating and shaft coupling rating at the reference speed and the maximum rated operating temperature, typically reported as horsepower. The method, calculation, documentation and reporting are detailed in ISO 15551:2023, A.3.1.

• • 1. Flexshaft
       1. Two axes relative displacement
          1. General

The objective of the two axes relative displacement test is to verify the displacement is within a reasonable range, the flexshaft can transmit power more effectively, reduce energy losses and improve transmission efficiency.

• • • • 1. Test equipment and procedure

Fix one end of the coupling using the locking block, as shown in Figure B.1, and swing the other end radially while keeping it parallel to the other coupling. Measure the relative displacement by micrometers when the maximum displacement is reached.

Key

1 locking block 1

2 locking rod

3 locking block 2

4 flat key

5 locating sleeve

6 tested flexshaft 1

7 cast iron platform

8 tested flexshaft 2

9 locking block 3

10 bolt

Figure B.1 — Schematic of relative displacement test equipment

• • • • 1. Documentation and reporting

The following data shall be documented:

a) material certification data, diameter of both end couplings and shaft, and machined features;

b) unique identifiers and type descriptions of the test equipment and instrumentation;

c) two axes relative displacement.

• • • 1. Static load
         1. General

The objective of the static load test is to verify the maximum load that the flexshaft can withstand under static conditions, thus ascertaining its rated load capacity. Ensure that the flexshaft can endure the torque and force during the actual operation, preventing damage or failure due to excessive load.

• • • • 1. Test equipment and procedure

The supplier/manufacturer shall use the following test equipment and procedure:

a) As a minimum, the test equipment shall comprise of a axial force loading device, a drive motor for loading the torque, equipment to regulate test load. The test equipment in Figure B.2 can be used as a reference.

b) Properly install the flexshaft between the two ends of the flanges;

c) load the axial force gradually via the axial force loading device;

d) load the rated torque of motor;

e) observe for any deformation or damage to the flexshaft.

Key

1 load motor

2 cast iron platform

3 transmission unit

4 mating flange 1

5 flexshaft

6 lead screw

7 mating flange 2

8 axial force loading device

9 movable crossbeam

Figure B.2 — Schematic of load test equipment

• • • • 1. Documentation and reporting

The following data shall be documented:

a) test duration;

b) the rated torque of motor;

c) static load capacity.

• • • 1. Static overload
         1. General

The objective of the static overload test is to verify the ultimate load that the flexshaft can withstand, clarify its load-bearing boundary beyond the normal operating range, and provide crucial data for judging the safety of the flexshaft under extreme working conditions.

• • • • 1. Test equipment and procedure

The test equipment and procedure are same as for static load test (B.3.2.2), but the motor's rated torque needs to be increased to 1,2 times for the test. After test, observe for any deformation or damage to the flexshaft.

• • • • 1. Documentation and reporting

The following data shall be documented:

a) test duration;

b) the ultimate torque loaded by motor;

c) static overload capacity.

• • • 1. Dynamic load
         1. General

The objective of the dynamic load test is to verify the ability of the flexshaft withstand alternating torques in both clockwise and counter-clockwise directions in a short period when the downhole-drive system gets stuck.

• • • • 1. Test equipment and procedure

The test equipment is same as for static load test (B.3.2.2). The supplier/manufacturer shall use the following test procedure:

a) Properly install the flexshaft between the two ends of the flanges;

b) load the axial force gradually via the axial force loading device;

c) load a 1,2 times rated torque alternately in the clockwise and counter-clockwise directions each minute, and record the angle of twist;

d) observe for any deformation or damage to the flexshaft.

• • • • 1. Documentation and reporting

The following data shall be documented:

a) test duration;

b) test frequency and number of tests;

c) angle of twist.

• • • 1. Transmission efficiency
         1. General

The objective of the transmission efficiency test is to align the eccentric movement of the pump rotor and ensure concentric movement with the seal chamber section, ensuring the efficient operation of the downhole-system.

• • • • 1. Calculation method

Use a torque measuring device to measure the torque of the input shaft and the output shaft of the flexshaft, and calculate the transmission efficiency according to Formula (B.1).

(B.1)

where

ƞ_f is flexshaft transmission efficiency;

T₃ is torque of the input flexshaft expressed in N∙m or in∙lb;

T₄ is torque of the output flexshaft expressed in N∙m or in∙lb.

• • • • 1. Documentation

The following data shall be documented:

a) torque of the input shaft;

b) torque of the output shaft;

c) transmission efficiency.

• • 1. Seal chamber section

The rating requirements and methods for the seal chamber section are executed In accordance with Table A.1, ISO 15551:2023, the test shall be done at PCP speed, 0~ 500 rpm.

• • 1. GRU
       1. Reduction ratio
          1. General

The objective of the reduction ratio calculation/test is to verify the Whether there is a good match in rotational speed between the motor and the load.

• • • • 1. Calculation and method

The reduction ratio of a single - stage planetary gear reducer shall be calculated using Formula (B.2).

(B.2)

where

i_s is reduction ratio of a single - stage planetary gear reducer;

N_p is number of teeth of the planetary gear;

N_r is number of teeth of the internal gear ring;

N_s is number of teeth of the sun gear;

n_p number of planetary gears in each stage.

The reduction ratio of a multi - stage planetary gear reducer shall be calculated using Formula (B.3).

(B.3)

where

i_m is reduction ratio of a multi - stage planetary gear reducer;

i_n is reduction ratio of n stage.

In practical applications, the calculation methods for planetary gear reducers with different structures and configurations may vary. Also, factors such as gear overlap ratio, transmission efficiency, and load need to be taken into account. It is advisable to calculate according to Formula (B.4) based on the measured rotational speeds of the input shaft and the output shaft.

(B.4)

where

i is reduction ratio;

n_i rotational speed of the input shaft expressed in r/min;

n_o rotational speed of the output shaft expressed in r/min.

• • • • 1. Documentation

The following data shall be documented:

a) type of the GRU, stage number of the planetary gear reducer, and unique identifier (such as serial number);

b) number of teeth of the planetary gear;

c) number of teeth of the sun gear;

d) number of teeth of the internal gear ring;

e) number of planetary gears in each stage;

f) reduction ratio.

• • • 1. Transmission efficiency
         1. General

The objective of the transmission efficiency test is to verify the power demand, operating speed and load characteristics of the motor, ensuring the efficient operation of the system.

• • • • 1. Calculation method

At the input end of the GRU, apply the rated output torque of the motor. Use a torque measuring device to measure the torque of the input shaft and the output shaft of the GRU, and calculate the transmission efficiency according to Formula (B.5).

(B.5)

where

ƞ_g is GRU transmission efficiency;

T₁ is torque of the input GRU expressed in N∙m or in∙lb;

T₂ is torque of the output GRU expressed in N∙m or in∙lb.

• • • • 1. Documentation

The following data shall be documented:

a) rated output torque of the motor;

b) torque of the input shaft;

c) torque of the output shaft;

d) transmission efficiency.

• • 1. Three-phase asynchronous motor

The design validation rating requirements and methods for three-phase asynchronous motors shall be in accordance with Table A.1, ISO 15551:2023.

• • 1. PMM
       1. No-load operating current
          1. General

The no-load operating current may be validated in accordance with the test method provided in this subclause. If any other method of validation is used, the suppliers/manufacturers shall reach an agreement with users/purchasers and provide documented information on the validation process.

• • • • 1. Test equipment and procedure

Adjust the motor to rated speed at rated voltage under no-load conditions, allowing mechanical losses to stabilize. Record the current value when the difference between two readings within 5 minutes does not exceed 3 % of the previous reading.

• • • • 1. Documentation

Record the testing conditions, testing process, and measurement results, including the motor's no-load current, in amperes.

• • • 1. No-load back electromotive force
         1. General

Suppliers/manufacturers shall provide the no-load back electromotive force of PMM according to the functional requirements and operating conditions specified in the functional specification.

The no-load back electromotive force may be validated in accordance with the test method provided in this subclause. If any other method of validation is used, the suppliers/manufacturers shall reach an agreement with users/purchasers and provide documented information on the validation process.

• • • • 1. Test equipment and procedure

B.3.6.2.2.1 General

The determination of no-load back electromotive force is a test specific to permanent magnet synchronous motors. It can be performed using either the back-drive method or the minimum current method, with the back-drive method being recommended.

B.3.6.2.2.2 Back-drive method (generator method)

Mechanically connect the prime mover to the motor under test. Drive the motor at synchronous speed, operating it as a generator under no-load conditions. Measure the voltages at the three output terminals of the motor separately, and calculate the average value to determine the no-load back electromotive force line voltage. Record the temperature of the motor's stator core and the ambient temperature at this point.

B.3.6.2.2.3 Minimum current method

Operate the motor under no-load conditions at rated voltage and frequency until it stabilizes. Adjust the external terminal voltage to minimize the no-load current. The external terminal voltage at this point can be approximately considered as the no-load back electromotive force of the motor. Measure the voltages at the three outlet terminals of the motor separately and calculate the average value to approximate the no-load back electromotive force line voltage. Record the temperature of the motor core and the ambient temperature at this point.

• • • • 1. Documentation

Record the test conditions, test procedures, measurement results, and no-load back electromotive force, expressed in volts.

• • • 1. Motor efficiency and power factor
         1. General

Suppliers/manufacturers shall provide the motor efficiency and power factor of PMM according to the functional requirements and operating conditions specified in the functional specification.

The motor efficiency and power factor may be validated in accordance with the test method provided in this subclause. If any other method of validation is used, the suppliers/manufacturers shall reach an agreement with users/purchasers and provide documented information on the validation process.

• • • • 1. Test equipment and procedure

The test equipment in Figure B.3 can be used as a reference.

Apply loads to the motor using appropriate equipment, such as a load motor or a dynamometer. Measure the torque using a torque measurement instrument with an accuracy class of no less than 0,5. It is recommended to use temperature sensors (embedded at the ends of the stator windings) to measure the winding temperature.

Key

1 load motor

2 torque meter

3 coupling

4 tested PMM

5 pressure and temperature Sensor

6 vibration sensor

7 bracket

Figure B.3 — Schematic of test device

Apply load to the motor at six load points. Four load points are set at 25 %, 50 %, 75 %, and 100 % of the rated load, with two additional points at 125 % and 150 % of the rated load, chosen within the range above 100 % but not exceeding 150 %. The loading process starts from the maximum load and sequentially decreases to the minimum load. Conduct the test as quickly as possible to minimize temperature changes in the motor during the process.

At each load point, measure the line voltage U₁, the line current I₁, the input power P₁, the torque T, the frequency f (or the rotating speed n), the maximum temperature of the stator winding θ_t, (or the terminal resistance of the stator winding, R_t), and the cooling medium temperature, θ_f.

• • • • 1. Calculation

a) Calculate the power factor in accordance with Formula (B.6).

(B.6)

where

cosφ is power factor;

P₁ is input power of motor expressed in kW;

U₁ is line voltage of motor expressed in V;

I₁ is line current of motor expressed in A.

b) Calculate motor efficiency in accordance with Formula (B.7).

(B.7)

where

ƞ_m is motor efficiency;

P₁ is input power of motor expressed in kW or HP;

P₂ is output power of motor expressed in kW or HP.

c) Calculate the output power in accordance with Formula (B.8) or Formula (B.9).

        (metric units) (B.8)

     (US customary units) (B.9)

where

T is test torque of motor expressed in N∙m or in∙lb;

n is rotational speed of motor expressed in r/min.

• • • • 1. Documentation

Record the test conditions and data in accordance with Table B.2. Record the power factor and the motor efficiency corresponding to different load rates in Table B.3 in accordance with the calculation method specified in B.3.6.3.3.

Table B.2 — Test data

Table B.3 — Performance parameters

1. 
   (normative)
   
   Performance evaluation
   1. General

This annex contains the requirements of performance evaluation procedure to verify whether the downhole-drive systems meet the performance requirements. Two grades of performance evaluation have been established. Users/purchasers shall select the appropriate performance evaluation grade.

All tests shall conform to the documented procedures of suppliers/manufacturers and shall be conducted by qualified personnel. Tests shall be completed prior to shipment. Before performing the performance evaluation, users/purchasers and suppliers/manufacturers shall reach an agreement on the testing parameters, acceptance criteria, and testing sequence. All tests shall comply with the requirements in Clause 7.

• 1. Performance evaluation rating

Users/purchasers shall specify the performance evaluation grade detailed in Table C1. This document defines three performance evaluation grades:

— F1: highest level of functional evaluation;

— F2: intermediate level of functional evaluation;

— F3: basic level of functional evaluation.

Table C.1 — Performance evaluation rating requirements

• 1. Seal chamber section

Performance evaluation and testing of seal chamber section shall be conducted in accordance with Table C.3, ISO 15551:2023.

• 1. Three-phase asynchronous motor

Performance evaluation and testing of three-phase asynchronous motor shall be conducted in accordance with Table C.4, ISO 15551:2023.

• 1. PMM
     1. Air tightness
        1. General

This clause specifies the requirements for the procedures, documentation and reporting, test results of the air tightness test.

• • • 1. Test method

a) Seal each connection of the motor using dedicated protective covers.

b) Introduce dry gas into the inner cavity of the motor from one end, with a test pressure of 0,35 MPa for 5 minutes. Meanwhile, apply soap water to all connections and threads to check for bubbles or leakage.

• • • 1. Documentation and reporting

The following test information shall be recorded:

a) Location of the test;

b) Date of the test;

c) Testing pressure and testing duration;

d) Test conclusions.

• • • 1. Test results

The motor shall have good sealing performance. Under a pressure of 0,35 MPa, with a test duration of 5 minutes, no leakage shall occur at any of the sealed connection points.

• • 1. Vibration
       1. General

This clause specifies the requirements for the procedures, documentation and reporting, test results of the vibration test.

• • • 1. Measuring method

a) Place the test motor on an inclined test bench, as shown in figure C.1, and select three bearing measurement points: upper, middle, and lower.

b) Install two vibration sensors at each bearing measurement point to measure vibration values in the X and Y directions.

c) Run the motor at no load and rated speed for half an hour and measure the vibration values at each point.

Key

1 uppper vibration sensor

2 tested PMM

3 V motor bracket

4 middle vibration sensor

5 lower vibration sensor r

6 work bench

Figure C.1 — Schematic of vibration test device

• • • 1. Documentation and reporting

The following test information shall be recorded:

a) Location of the test;

b) Date of the test;

c) Type and model of the test motor;

d) Vibration value at each bearing measurement point.

• • • 1. Test results

Motor vibration shall meet the acceptance criteria agreed upon by users/buyers and suppliers/manufacturers. If no acceptance criteria are defined between users/buyers and suppliers/manufacturers, the vibration intensity shall meet the criteria for "good" or above as outlined in API RP 11S8, Appendix C1.

• • 1. Maximum starting torque
       1. General

This clause specifies the requirements for the procedures, documentation and reporting, test results of the maximum starting torque test.

• • • 1. Measuring method

a) Perform the test with the motor in a cold state and measure within the rated speed range.

b) Preload a certain torque on the motor shaft and apply a rotating speed within the motor’s rated range. If the motor starts normally, disconnect the power to stop the motor.

c) Continue to increase the load torque on the shaft and repeat the above steps until the motor fails to start when the load torque is increased further. Record the last load torque.

d) Measure the torque at three different rotor angles and take the minimum value.

• • • 1. Documentation and reporting

The following test information shall be recorded:

a) Location of the test;

b) Date of the test;

c) Type and model of the test motor;

d) Torque values measured at different rotor angles when the motor has stopped.

• • • 1. Test results

The motor's maximum starting torque shall meet the acceptance criteria agreed upon by users/buyers and suppliers/manufacturers. If no acceptance criteria are defined between them, the maximum starting torque shall be at least 1,5 times the rated torque.

• • 1. Overload torque
       1. General

This clause specifies the requirements for the procedures, documentation and reporting, test results of the overload torque test.

• • • 1. Test method

a) Measure under rated speed and rated voltage conditions.

b) During the test, a load with uniform adjustability, such as a torque measuring instrument, brake, dynamometer, or calibrated generator, should be used.

c) Preload the rated torque on the motor shaft and set the motor to the rated speed range. Adjust the load torque to 1,5 times the rated torque of the submersible motor, and record the motor’s stable running time.

• • • 1. Documentation and reporting

The following test information shall be recorded:

a) Location of the test;

b) Date of the test;

c) Type and model of the test motor;

d) Stable running time of the motor when the load torque is 1,5 times the rated torque.

• • • 1. Test results

The motor's overload torque shall meet the acceptance criteria agreed upon by users/buyers and suppliers/manufacturers. If no acceptance criteria are defined between them, the motor shall run stably for at least 1 minute when the overload torque is 1,5 times the rated torque.

1. 
   (informative)
   
   Downhole-drive systems selection
   1. General

Proper selection of downhole-drive systems requires research and evaluation of structure and power transmission to ensure the system's safety and continuous operation. As key considerations, the following points are listed, and it is recommended that suppliers/manufacturers choose products with rated values equal to or greater than the requirements under actual application conditions.

• 1. Submersible motor selection
     1. Hydraulic power

Calculate hydraulic power N_H in accordance with Formula (D.1) or Formula (D.2):

                 (metric units) (D.1)

             (US customary units) (D.2)

where

N_H is hydraulic power expressed in kW or HP;

q is well fluid production rate expressed in m³/d;

ρ is well fluid density expressed in kg/m³;

g is unit for g-force expressed in m/s²_, the commonly used value is approximately 9,81 m/s²;

H is effective head expressed in m.

Calculate effective head H in accordance with Formula (D.3):

(D.3)

Calculate frictional resistance loss along the way H_f in accordance with Formula (D.4):

(D.4)

Calculate head loss caused by the pressure at the wellhead H_p in accordance with Formula (D.5):

(D.5)

• • 1. Output power

Calculate output power N_A in accordance with Formula (D.6). The transmission efficiency from the motor output to the intake of the PCP is generally taken as multiplying the transmission efficiency of all components.

(D.6)

where

N_A is output power expressed in kW or HP;

η_mp is transmission efficiency from motor output to PCP discharge.

• • 1. Rated power

Based on the calculated motor output power N_A, the motor selection is determined by referring to the rated power series in Table D.1 or Table D.2.

Table D.1 — Basic parameters of submersible motors (Constant voltage)

Table D.2 — Basic parameters of submersible motors (Constant current: 31A)

Bibliography

[1] ISO 15136‑1, Petroleum and natural gas industries — Progressing cavity pump systems for artificial lift— Part 1: Pumps

[2] ISO 15136‑2, Petroleum and natural gas industries — Progressing cavity pump systems for artificial lift — Part 2: Surface-drive systems

[3] ISO 15551:2023, Petroleum and natural gas industries — Drilling and production equipment — Electric submersible pump systems for artificial lift

[4] ANSI/AWS D1.1/D1.1M, Structural welding code — Steel

[5] ANSI/AWS B2.1, Specification for welding procedure and performance qualification

[6] ANSI/NCSL Z540.3, Requirements for the calibration of measuring and test equipment

[7] API RP 11S3-1999, Recommended Practice for Electric Submersible Pump Installations

[8] API RP 11S9-2023, Permanent Magnet Motor Safety

[9] ASTM E165/E165M -23, Standard practice for liquid penetrant testing for general industry

[10] ASTM E709 -21, Standard guide for magnetic particle testing

[11] BS 2M‑54, Specification for temperature control in the heat treatment of metals