GB/T 17389-2026Manufacture, inspection and application of electric submersible pump cable (English PDF)

4.1 Classification

4.1.1 According to their function, they are divided into. power cables and lead cables.

4.1.2 According to the shape of the cable cross-section, cables are classified as. round cables and flat cables.

4.1.3 According to the rated voltage level, they are divided into. 3kV and 6kV.

4.1.4 According to the temperature resistance rating, they are divided into. 90°C, 120°C, 150°C, 180°C, and 204°C.

4.2 Structure Typical cable structures are shown in Figures 1 and 2.

5.1 General Requirements

5.1.1 The three-phase DC resistance imbalance rate should not exceed 2%.

5.1.2 The measured insulation resistance value of the cable, when converted to 15.6°C, shall not be less than the minimum insulation resistance value of the cable specified in Appendix A.

5.1.3 The DC withstand voltage of the cable shall be tested according to method 7.3.5, and the withstand voltage shall be maintained for 5 minutes without breakdown.

5.1.4 The DC withstand voltage of the cable with cable head shall be tested according to method 7.3.5, and the withstand voltage shall be maintained for 5 minutes without breakdown.

5.1.5 The DC leakage current of the cable shall be tested according to method 7.3.6.When the test value is converted to 15.6°C, it shall not exceed the specification in Appendix A.

5.2 Materials

5.2.1 The conductor is generally made of copper, and the conductor surface should be smooth, without obvious oxidation marks or rust spots. When polypropylene insulation is used... When this is done, the copper conductor should be tin-plated.

5.2.2 The measured DC resistance of the conductor at 20°C should not exceed the standard value specified in Table 1.

5.2.3 Polyimide film should be used in environments not exceeding 232°C. When used as insulation for submersible electric pump cables, it should be used in conjunction with ternary dielectric film. Ethylene propylene rubber or fluoroplastics are used together.

5.2.4 Polyimide film is generally preferred when the dielectric strength (V/mm) is high and the insulation layer thickness is small.

5.2.5 The lead sheath shall be free from defects such as pinholes, cracks and impurities.

5.2.6 A layer of polytetrafluoroethylene film or polyester film shall be wrapped around the outer sheath of flat cables, and the outer layer shall be wrapped with nylon cloth or polyester yarn. Braiding. When the inner sheath is a lead sheath, wrapping tape or braided layers may be used directly on the outside of the sheath. The insulation layer of the round cable core and the sheath layer... An oil-resistant padding layer is permitted between layers. The overlap ratio of the wrapping layer should be no less than 50%, and the density of the braided layer should be no less than 90%.

5.2.7 The weld joints of the armored tape should be flat and firm, free from defects such as cracks, loosening, and dents.

5.2.8 The mechanical connection between the cable head armor and the cable head housing shall be secure.

5.2.9 Before connecting the lead cable with a cable head to the power cable, measure its insulation resistance value. The insulation resistance value of thermoplastic cables should be greater than [value missing]. The insulation resistance of thermosetting resin should be greater than 800 MOmega·km, with a resistance of 1000 MOmega·km.

5.2.10 Other manufacturing technical parameters of submersible pump cables shall comply with the provisions of GB/T 16750.

5.2.11 Commonly used materials for submersible electric pump cables are shown in Table 2.

5.3 Dimensions

5.3.1 The external dimensions of the cable shall conform to the provisions of Table 3.

5.3.2 Conductor nominal diameter tolerance. conductor nominal diameter ±1%.

5.4 Factory Inspection The factory testing items and test methods for submersible electric pump cables shall comply with the provisions of GB/T 16750.

6.1 General Rules

6.1.1 Generally, round cables should be selected. When the annular space of the oil jacket does not meet the installation conditions of round cables, flat cables should be selected.

6.1.2 Flat groove pulleys should be used when installing flat cables, and angle-wrapped pulleys should be used when installing round cables. The pulley diameter should not be less than [missing value]. 1220mm.

6.1.3 The bending radius of the cable shall comply with the provisions of JB/T 5332.1.

6.1.4 The cable specifications and dimensions should be selected based on conductivity and well annular gap. The minimum conductor size should be determined based on the required current of the motor and... Permissible voltage drop selection (see Appendix B).

6.1.5 The selection of submersible pump cables should take into account factors such as the actual oil well environment, gas type, and gas concentration.

6.1.6 The armor should be interlocking, which minimizes the possibility of the armor coming loose and does not hinder the lifting and lowering operations.

6.1.7 When installing flat armored cables, the exposed side of the steel strip should face upwards.

6.2 Material Selection

6.2.1 The selection of insulation materials for submersible electric pump cables shall comply with the provisions of Table 4.

6.2.2 Lead sheaths are recommended for H2S wells.

6.2.3 Galvanized steel strips are suitable for most oil well environments.

6.2.4 Stainless steel strips are recommended for oil well environments with strong corrosiveness. Generally, stainless steel grades 304 and 316L are preferred.

6.2.5 Monel steel strips are recommended for harsh well conditions containing CO2, H2S, and high-temperature concentrated salt solutions.

6.3 Connection A connection refers to the connection between two cables. The following connection methods are used.

a) A connection method in which the ends of two conductors are directly fused together using a welding process;

b) A connection method in which the crimping tube and the conductor are tightly bonded by mechanical crimping. When welding equipment and conditions are available, fusion welding is the preferred method for joining.

6.4 Termination For applications such as wellheads, submersible motors, and downhole packers, the following connection method is used for termination. the wellhead and packer termination uses a submersible motor... Pump lead cable connection; if there is sufficient space between the motor and the bushing, the cable head should be directly connected to the power cable.

6.5 Fixes

6.5.1 The main repair methods for insulation, sheathing, and armor are.

a) Use thermoplastic materials as insulation and perform molding repair using a high-temperature molding process;

b) Use uncured thermosetting tape as insulation and sheath, and perform vulcanization repair using a high-temperature molding process;

c) Use thermoplastic materials, such as vulcanized, non-vulcanized, or low-temperature vulcanizable tapes, as insulation and sheathing materials, and wrap them using a winding process. repair;

d) Use lead sheet as a lead sheath, wrap it around the outside of the insulation layer, overlap it with the original lead sheath, and repair the lead sheath by welding;

e) Spiral-wrap the armor around the entire joint, with its end overlapping the original armor. Secure the armor using welding or crimping techniques. Repair of the coating layers.

6.5.2 See Appendix C for a schematic diagram of cable repair.

7.3.1 Preparations before testing

7.3.1.1 Cables with cable heads Before inspecting cables with cable heads, prepare them according to the following regulations.

a) Prepare cable ends, cable heads, connectors, and wire ends. Before cleaning, avoid electrical contact and ensure adequate electrical supply. Insulation performance should be ensured to prevent arcing during testing. Cable heads should be thoroughly cleaned with a non-conductive solvent and... It must be completely dry. The heat shrink tubing, motor oil, and other insulating components to be tested should be kept clean.

b) Ensure that the cable system is at room temperature and that gases are vented.

c) Perform a continuity check; a continuous conductive path should be formed between the cable head sheath and the cable armor. Each phase conductor should be continuously checked. Conduct a resistance test to ensure the cable cores or connections are intact. Simultaneously, the conductor resistance of each phase cable core should be tested to identify... Are there any weak connections or conductor defects?

7.3.1.2 Cables without cable heads Before testing cables without cable heads, prepare them according to the following regulations.

a) Remove all materials except the armor and insulation layer, including the sheath and oil-resistant pad, leaving only the insulation layer. At both ends of the cable... At the end, the exposed length of the insulation material should not be less than 300mm.

b) Thoroughly clean the surface with a non-conductive solvent and then dry it completely.

c) The insulation layer at the cable test end should be stripped for a length of not less than 15mm, exposing the conductor (the phase under test) end to the conductors of other phases. The distance between the ground and the surface should be no less than 150mm.

d) At the other end of the cable, silica gel putty, electrostatic putty, or a plastic cap should be used for corona discharge protection, or the conductor end of the phase under test should be connected to... The distance between conductors or ground in other phases should be no less than 150 mm.

7.3.2 Appearance and Structural Dimensions

7.3.2.1 Armor Quality Visually inspect the surface of the armor belt.

7.3.2.2 Cable External Dimensions Use vernier calipers to measure the external dimensions of the cable.

7.3.2.3 Conductor Diameter Select three evenly spaced points on the bare wire at least 100mm from the cable end, and measure them using a vernier caliper or micrometer. At each point... The measurement results must be accurate to two decimal places.

7.3.3 Three-phase DC resistance imbalance rate

7.3.3.1 Measurement Method 7.3.3.1.1 When using a DC double bridge or micro-ohmmeter for measurement, the distance between the potential clamp and the current clamp should not be less than the circumference of the core wire.

1.5 times. 7.3.3.1.2 Measure the DC resistance Ru, Rv, and Rw of the three-phase cable respectively.

7.3.3.2 Calculation of Measurement Results 7.3.3.2.1 The DC resistance between phases of a three-phase cable is calculated according to formula (1).

7.3.4 Insulation Resistance

7.3.4.1 Measurement Method An insulation resistance tester was used to measure the insulation resistance to ground and between phases of each phase of the three-phase cable (the other two phases are connected to the armor tape). Discharge to ground after each phase measurement.

7.3.4.2 Calculation of Measurement Results 7.3.4.2.1 The temperature coefficient refers to the value at a temperature of 15.6°C. For field testing, it should be corrected using a temperature correction factor. The value at 15.6°C. Different insulating materials exhibit different temperature coefficients. In fact, the temperature coefficient of most insulating materials is 1.03.Table 6 lists the temperature coefficients. The temperature correction factor is 1.03.For temperatures not listed in Table 6, the temperature correction factor is calculated according to formula (3).

7.3.5 DC withstand voltage DC voltage measurements are performed according to the following steps.

a) A DC withstand voltage tester shall be used. The device shall have short-circuit instantaneous overcurrent protection and reliable grounding.

b) Apply the DC voltage specified in Table 7 to each of the three-phase cables (and the DC voltage specified in Table 8 to each of the cables with cable ends). The voltage is applied to the first phase (the other two phases are connected to the armor strip and grounded, see Figure 3 for wiring method). The applied voltage during repeated withstand voltage tests is as shown in Table 7. Or 80% of the voltage specified in Table 8.

c) Begin applying pressure at a starting value 40% lower than the specified voltage, gradually increasing it to (100±3)% of the specified voltage, and maintaining this level. 5 minutes; then, reduce the voltage to below 40% of the specified voltage and disconnect the power supply. Power should not be suddenly cut off while the voltage is high. To prevent overvoltage.

7.3.6 DC Leakage

7.3.6.1 Measurement Method 7.3.6.1.1 A DC leakage tester was used to measure the armor strip on each of the three phases (see Figure 4 for wiring method). 7.3.6.1.2 The test voltage shall conform to the specifications in Table 7 or Table

8.The pressure shall be applied evenly and smoothly, and the time to reach the maximum voltage shall not be less than [amount missing]. After 10 seconds, once the specified voltage value is reached, maintain this voltage for 5 minutes and record the leakage current. The voltage reduction should be slow and steady.

7.3.6.2 Calculation of Standard DC Leakage Current Value The standard DC leakage current value is calculated at 15.6°C based on the ratio of the corresponding test voltage to the cable's minimum insulation resistance value, according to the formula... Calculate using equation (6).

7.3.7 Time Domain Reflectometer (TDR) Testing The time domain reflectometer (TDR) testing steps are as follows:

a) Preparations for testing the cable system in accordance with the procedures specified in 7.3.1.

b) Because the velocity coefficient (the ratio of pulse velocity in the cable to the velocity in the air) is affected by temperature, pressure, medium, etc., it is necessary to use a pre-existing test kit before testing. The time-domain reflectometer is calibrated based on the cable length.

c) Establish an initial characteristic spectrum for the newly installed cable, recording the pulse duration, pulse amplitude, and velocity coefficient settings. Data such as...

d) Use the minimum pulse width to ensure the reflected pulse has a sufficiently large amplitude and shape, and record the pulse duration, amplitude, and shape. Parameters such as velocity coefficients are compared and analyzed with the original characteristic spectrum.

e) By analyzing the data, determine the location of the fault point where a significant change in insulation impedance occurs. If the fault is determined to be at the top of the cable, allow... The operator does not remove the entire tubing string.

7.3.8 Molai Loop Location (Bridge Fault Detector) Detection The detection steps for the Molai loop location (bridge fault detector) are as follows:

a) After the equipment is pulled out of the well, prepare the cable for testing in accordance with the procedure specified in 7.3.1.

b) Use a Molex loop locator to perform a DC high voltage test on the cable.

c) Connect the two wires of the bridge circuit correctly to the two ends of the conductor to be measured. Use a DC voltage and adjust the potentiometer to make the bridge circuit... The displayed value is zero. The potentiometer reading is related to the percentage of cable length remaining; the location of the fault is determined by the potentiometer reading.

d) The instrument should be reconnected when testing for phase-to-phase faults.