1、Recommended Practice on Application and Testing of Electric Submersible Pump Seal Chamber SectionsAPI RECOMMENDED PRACTICE 11S7FIRST EDITION, JULY 1993REAFFIRMED, OCTOBER 2013Recommended Practice on Application and Testing of Electric Submersible Pump Seal Chamber SectionsUpstream SegmentAPI RECOMME
2、NDED PRACTICE 11S7FIRST EDITION, JULY 1993REAFFIRMED, OCTOBER 2013Complimentary Copy for Committee UseAPI RPt11S7 93 0732290 0514610 465 2 American Petroleum Institute TABLE OF CONTENTS Page POLICY . 4 FOREWORD . 5 SECTION 1 - GENERAL 1.1 Introduction E 1.2 Scope 6 SECTION 2 - DEFINITIONS . 7 SECTIO
3、N 3 - FUNCTIONS OF THE SEAL CHAMBER SECTION 3.1 General . 8 3.3 Pressure Equalization . 8 3.4 Exclude Well Fluids 8 3.5 Thrust Compensation 8 3.6 Torque Transmittal . 8 4.1 ShaR . 9 4.2 ShaR Seals . 9 4.3 Static Seals 9 4.4 Bearings . 9 4.5 Bladder . 9 4.6 Housings 9 4.7 Labyrinth Chamber . 9 4.8 Bl
4、ocking Fluid . 10 4.9 Bladder Chamber 10 4.10 Relief Valves 10 4.11 Check Valves . 10 4.12 Couplings . 10 5.1 Temperature 16 5.2 Fluid Characteristics . 16 5.3 Well Geometry . 16 5.4 Equipment 16 5.5 Operating Conditions 16 6.1 Shafts . 18 6.2 Shaft Seals, Joints and Vents 18 6.3 Idle Power Loss . 1
5、8 6.4 elief Valves 18 6.5 Bladder Pressure Test . 18 SECTION 7 - SUPPLEMENTAL VIBRATION TESTING 20 8.1 Check for Leaks . 21 8.2 Thrust Load Testing . 21 8.3 Tests . 21 9.1 Purpose 23 9.2 General Component Analysis . 23 9.3 Additional Checks 27 3.2 Provide Oil Expansion Volume . 8 SECTION 4 - COMPONE
6、NTS SECTION 5 - APPLICATION AND SELECTION CONSIDERATIONS SECTION 6 - ACCEPTANCE TESTING SECTION 8 - RE-USE TESTING SECTION 9 - TEARDOWN ANALYSIS API RPlrLLS7 93 0732290 0514611 3TL RP 1157: Recommended Practice on Application and Testing of Electric Submersible Pump Seal Chamber Sections TABLE OF CO
7、NTENTS (Continued) 3 Page 10.1 Shipping . 28 10.2 Handling 28 10.3 Storage . 28 SECTION 10 - HANDLING, SHIPPING, AND STORAGE API RP*lLS7 93 W 0732290 05l4bl2 238 4 American Petroleum Institute POLICY API PUBLICATIONS NECESSARILY ADDRESS PROB- LEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRC
8、UMSTANCES, LOCAL, STATE AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING TO MEET DUTIES OF EMPLOYERS, MANUFACTURERS, OR SUPPLIERS TO WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERN- ING HEALTH AND SAFETY RISKS AND PRECAU- TIONS, NOR UNDERTAKI
9、NG THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPA- PATENT. NEITHER SHOULD ANYTHING CON- RATUS, OR PRODUCT COVERED BY LETTERS
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12、VE YEARS. SOMETIMES A ONE-TIME EX- PUBLICATION DATE AS AN OPERATIVE API STAN- IS PUBLISHED ANNUALLY AND UPDATED QUAR- API RPxLLS7 93 H 0732290 05L4b13 374 H RP llS7: Recommended Practice on Application and Testing of Electric Submersible Pump Seal Chamber Sections FOREWORD 5 (a) This publication is
13、under the jurisdiction of the API Committee on Standardization of Production Equipment. (b) American Petroleum Institute (API) Recommended Practices are published to facilitate the broad availabil- ity of proven, sound engineering and operating practices. These Recommended Practices are not intended
14、 to obvi- ate the need for applying sound judgement to when and where these Recommended Practices should be utilized. (c) The formulation and publication of API Recommended Practices is not intended to, in any way, inhibit anyone from using any other practice. (d) Any Recommended Practice may be use
15、d by anyone desiring to do so, and a diligent effort has been made by API to assure the accuracy and reliability of the data contained herein. However the Institute makes no rep- resentation, warranty or guarantee in connection with the publication of any Recommended Practice and hereby expressly di
16、sclaims any liability or responsibility for loss or damage resulting from its use, for any violation of any federal, state or municipal regulation with which an API recommendation may conflict, or for the infringement of any patent resulting from the use of this publication. API RP*11S7 93 m O732290
17、 0514614 O00 m 6 American Petroleum Institute SECTION 1 GENERAL 1.1 Introduction This recommended practice applies to the seal chamber section used in support of an electric submersible motor. Seal chamber sections are assemblies connected in tan- dem with oil filled motors to provide several suppor
18、ting functions to the ESP system. They are also referred to as protectors, equalizers, or seal sections. 1.2 scope This RP contains tutorial, testing, and failure evaluation information. It provides a general understanding of con- struction and functioning of seal chamber sections and identification
19、 of well conditions, system requirements and characteristics that influence component selection and application. Also included is information needed to evaluate causes of seal chamber section failures. Testing sections establish acceptable test procedures and criteria to help verify seal chamber sec
20、tion functionality. General shipping and handling information is also included. API RPU11S7 93 0732290 0514615 T47 RP 1157: Recommended Practice on Application and Testing of Electric Submersible Pump Seal Chamber Sections 7 SECTION 2 DEFINITIONS Bag - The bladder. Barrier Fluid - Blocking Fluid. Bl
21、adder - An elastomeric membrane within the seal chamber section that separates the filling fluid from the well fluid. Blocking Fluid - A heavy fluid occasionally used to separate well fluid and filling fluid. Chamber - The enclosed compartment which houses the labyrinth or bladdeds). Check Valve - M
22、echanical devices that allow one- directional flow of fluid when a differential pressure exists across the valve. It may not seal against positive pressure. Communication Hole - A passage to allow flow of fluid between chambers and from the top chamber to the wellbore. Coupling - The splined concent
23、ric mechanical connec- tion between the seal chamber section shaft and adjacent shafts. Drain Port - A port to allow draining of fluid from a chamber. Equalizer - Seal chamber section. ESP - Electric submersible pump. Filling Fluid - Motor oil. FIM - Full Indicator Movement: the total movement of an
24、 indicator when appropriately applied to a surface to measure its variation (per ANSI Y14.5M). Housing - A cylindrical casing that contains the com- ponents of the seal chambers. Labyrinth Chamber - A labyrinth chamber provides a fluid interface between the well fluid and motor oil. Separation is ma
25、intained by the difference in specific gravity of the fluids. Motor Oil - A dielectric oil used to insulate, lubricate, and cool the motor and seal chamber section. Motor Seal Section - An obsolete term for seal cham- ber section. Operating Temperature - Temperature of the compo- nent during operati
26、on. Protector - Seal chamber section. Relief Valves - Mechanical devices that allow one- directional flow of fluid when a pre-set differential pres- sure is exceeded across the valve. Seal Section - Seal chamber section. Shaft Seal - A device used to seal the interface be- tween the shaft and a stat
27、ionary component. Thrust - Axial force transmitted from the pump shaft to the top of the seal section shaft. Thrust Chamber -An assembly or a section of the seal chamber section which houses the thrust bearing assembly. Vent Port - A port to allow venting of air during the filling process. API RP+lZ
28、S7 93 m 0732290 0514blb 983 m i3 American Petroleum Institute SECTION 3 FUNCTIONS OF THE SEAL CHAMBER SECTION 3.1 General The seal chamber section has several functions that support operation of the liquid filled submersible motor and the centrifugal pump. These supporting functions must be addresse
29、d in any ESP confijpration. 3.2 Provide Oil Expansion Volume The motor and seal chamber section are filled with a dielectric oil that lubricates the bearings and cools the motor. During system installation, operation, and pull- ing, the motor oil will expand or contract. This change in the motor oil
30、 volume is accommodated by the seal chamber section. 3.3 Pressure Equalization The seal chamber section equalizes the pressure inside the motor with the well bore pressure and thus elimi- nates pressure differences across the shaft seals. 3.4 Exclude Well Fluids The seal chamber section prevents ent
31、ry of well fluid into the motor. 3.5 Thrust Compensation The seal chamber section carries downthrust transmit- ted from the pump to prevent loading the motor thrust system. An upthrust system is usually included to pro- tect the seal chamber section should an unusual operat- ing condition cause the
32、pump to develop upthrust. 3.6 Torque Transmittal The seal chamber section transmits torque from the motor shaft to the pump shaft. This function includes the reac- tion torque transmitted through the housings. API RP+LLS7 93 O732290 051YbL7 BIT FE 1157: Recommended Practice on Application and Testin
33、g of Electric Submersible Pump Seal Chamber Sections SECTION 4 COMPONENTS 9 See Figures 4.14 4.1B, and 4.1C for a general depiction of the seal chamber section. 4.1 Shaft: The shaft transmits torque from the motor to the pump. It also transmits the axial thrust generated by the pump to the thrust be
34、aring. Shaft straightness is fundamentally important in the reduction of vibration and assuring proper function of shaft seals and bearings. ShaR runout of 0.002“ FIM or more between bearing locations is likely to result in unacceptable vibration levels. 4.2 Shaft Seals: Shaft seals are used to seal
35、 the inter- face between the shaft and a stationary component. The most commonly used types are elastomeric bellows and metal bellows mechanical face seals. Radial lip seals are sometimes used. 4.2.1 Mechanical Face Seal: The sealing function of the face seal is accomplished by a stationary, primary
36、 seal ring bearing against the face of a mating ring mounted on a shaft. Axial pressure maintains the con- tact between the stationary and rotating mating rings. See Figures 4.2 and 4.3 for a description of components. 4.2.2 Raial Lip Seals: Sometimes used to provide the same function as Mechanical
37、Face Seals. Composed of a “U“ shaped stationary elastomeric or plastic ring sealing against the shaft or a shaft sleeve. See Figure 4.4 for a description of components. 4.3 Static seals are installed between surfaces where no relative motion exists. 4.3.1 O-Rings are elastomeric ring type seals used
38、 to keep well fluids from entering the seal chamber through housing joints, mechanical seals and flanges. Elastomeric O-rings have become widely used in static sealing applications because of their flexibility and resistance to compression set. O-rings are prone to damage during installation. Care m
39、ust be taken to insure that the O-ring sealing area is clean and free of scratches across the grooves in order to insure proper sealing. A small amount of lu- brication on the O-ring aids in assembly, but excessive lubrication can defeat sealing ability. The O-ring should never be forced over sharp
40、corners, threads, keyways, slots, or splines nor should its ID be stretched more than 100% upon installation. The O-ring should be placed in the groove so that it is not damaged as the components are assembled. It is good practice to not reuse O-rings. 4.3.2 Lead gaskets are commonly used to seal ve
41、nt plugs and drain and fill valves. Never re-use lead gaskets. 4.3.3 Fiber gaskets may be used under shipping caps during shipping but must not be used during unit installation. 4.4 Bearings: Both radial and thrust bearings are used in seal chamber sections. Sleeve and roller bearings are common exa
42、mples of radial bearings. Typical thrust bear- ings are fixed and pivot shoe types. 3 3 4.5 Bladder: The bladder forms a flexible barrier be- tween the motor oil and the well fluid thus preventing comingling of the two fluids. (See 4.9) 4.6 Housings (See Figures 4.1 the material should be matched to
43、 its intended operating temperature. Consider all temperatures (high and low) that the material will see in all other condi- tions of unit life, i.e. storage, shipping, testing, and installation. Also be aware that a “high temperature“ elastomer may not be the best selection for a low tem- perature
44、application. There are many different formulations with widely divergent properties and performance. Generally, ESP manufacturers specify the elastomer formulation used in various components and offer several choices for varying well conditions. Typical maximum service tem- peratures for several ela
45、stomers are shown below: Nitrile: 250 OF (121 “C) Highly Saturated Nitrile (HSN): 275 OF (135 “Cl Fluoroelastomer compounds: 325 OF (163 “C) Tetrafluoroethylendpropylene copolymer (TFEF): 350 OF (177 “C) It is important to ensure that the specific formulations selected are compatible with the operat
46、ing environ- ment. Each application should be reviewed with the ESP manufacturer for specific recommendations. 5.1.2 Operating temperature should be considered when selecting motor oil. In general, motor oil viscosity decreases as temperature increases. At operating tem- perature the motor oil visco
47、sity must be sufficient to provide lubrication for the seal chamber section bear- ings. ESP manufacturers typically offer several types of motor oil to accommodate a range of operating tem- peratures. Motor oil should be selected based on the manufacturers recommendation to ensure proper bear- ing o
48、peration. 5.1.3 The motor oil used in the seal chamber section must be compatible with the motor oil used in the motor. If the seal chamber section is to be serviced (filled) in a cold climate, the pour point of the motor oil should be considered to ensure proper filling of the unit. 5.2 Fluid Chara
49、cteristics 5.2.1 Water, oil, gas and brine are among the many fluids to be considered when selecting materials for the “wetted“ (in contact with well fluid) components of the seal chamber section. The wetted parts of the seal chamber section include housings, head, base, shaft, and shaft seal. Generally, housings, heads, and bases are available in carbon steel or high chrome alloys for added corrosion resistance. Special coatings can also be applied to these components for additional corrosion protection. Corrosion resistant materials such as monel, stainless steel, and inconel are commonl
