Thickened oil machine pumping horizontal well optical fiber monitoring production fluid profile testing system

Abstract

The invention relates to the technical field of oil and gas field development, in particular to a thickened oil machine pumping horizontal well optical fiber monitoring production fluid profile testing system which comprises an optical fiber, a slotted small-diameter oil pipe, a crossover coupling, a pump body, an oil pipe, an oil pipe hanger, an oil extraction four-way joint, a sucker rod and a ground control unit. 2, penetrating an optical fiber from the uppermost slit of the slit small-diameter oil pipe, and fixing the optical fiber on the inner side of the lower end of the slit small-diameter oil pipe; and thirdly, the slotted small-diameter oil pipe is put into a preset position in the well. According to the method, the purpose of monitoring the multi-section fracturing fluid production profile of the thickened oil pumping horizontal well is achieved, the problems that a flowmeter of the thickened oil well is not suitable and a pumping pipe column in the well is not easy to test are solved, the fluid production contribution rate and the fracturing effect of each cluster of reservoir are accurately known through accurate monitoring of the fluid production profile, and the method is suitable for large-scale popularization and application. And an important basis is provided for reservoir understanding and fracturing transformation scheme optimization.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and is a fiber optic monitoring liquid production profile testing system for heavy oil rod pumped horizontal wells. Background Art

[0002] China is rich in heavy oil resources, with huge proven and controlled reserves. Currently, it has become the fourth largest heavy oil producing country in the world. Due to the high viscosity and density of heavy oil, the flow resistance is large during the exploitation process, the driving efficiency is low, and the volumetric sweep efficiency is low. With the continuous deepening of heavy oil development, deep heavy oil with thin interbeds and poor physical properties has become an important target. For deep heavy oil, in order to improve the reservoir utilization rate, horizontal well staged fracturing has become the main process for heavy oil cold production. However, due to the strong reservoir heterogeneity, the productivity difference is large after fracturing. It is urgent to conduct liquid production profile testing on the post-fracture horizontal well to understand the productivity of each section and cluster, and provide an important basis for reservoir understanding and optimization of the fracturing transformation plan.

[0003] At present, the liquid production profile testing technologies for horizontal wells mainly include crawlers, continuous tubing connected flow meters (turbine flow meters, ultrasonic flow meters, electromagnetic flow meters) for monitoring, pre-set liquid production profile testing instruments in the horizontal section for monitoring, and fiber optic continuous tubing monitoring technology. Since heavy oil has a high viscosity and generally no natural productivity, when monitoring the liquid production profile of heavy oil horizontal wells, it is necessary to not only ensure normal bottom hole flow and production, but also overcome the problems that high-viscosity oil adheres to the turbine and probe, affecting the testing.

[0004] At present, the patent documents for the liquid production profile testing methods of rod pumped horizontal wells are as follows: The patent document with the publication number CN103075143A and the name of a liquid production profile testing method for rod pumped horizontal wells discloses connecting a long plunger hollow sucker rod pump to the bottom of the tubing, lowering it to the designed pump depth in the horizontal well, and seating the long plunger hollow sucker rod pump in the casing. The coiled tubing and the logging cable are synchronously lowered from the tubing to the lower part of the horizontal well liquid production profile to be tested section. By pressurizing the coiled tubing on the ground, the release sub is separated from the coiled tubing, and the coiled tubing is retrieved. A reciprocating ground lifting device is connected to the upper end of the tubing to perform reciprocating pumping actions, and the liquid production profile tester is started. By slowly lifting the test cable and moving the liquid production profile tester upward, the operation of testing while producing is carried out. Testing by dragging easily disturbs the oil-water distribution in the casing. At the same time, for wells with thick oil, it is easy for the sensors such as the turbine and probe to be adhered, resulting in large measurement errors.

[0005] The patent document with the publication number CN101403292 and the name of the liquid production profile testing process method for gas lift in rod pumped horizontal wells discloses using a gas lift production string to implement lifting, connecting the crawler to the liquid production profile tester and transporting it through the gas lift production string to the lower end of the test section. Nitrogen is used for lifting on the ground, and after stabilization, the cable is lifted to conduct liquid production profile testing. This method is applicable to horizontal wells with large production, and is not applicable to the liquid production profile testing of rod pumped horizontal wells with low production. Summary of the invention

[0006] The present invention provides a system for testing the production profile of a heavy oil horizontal well using optical fiber for monitoring the production of liquid, which overcomes the deficiencies of the prior art and can effectively solve the problems in the existing monitoring of the production profile of heavy oil horizontal wells that the flow meter for the heavy oil well is not applicable and the pumping pipe string in the well is difficult to test.

[0007] The technical solution of the present invention is achieved through the following measures: A system for testing the production profile of a heavy oil machine-pumped horizontal well using optical fiber to monitor the production, including an optical fiber, a slotted small-diameter oil pipe, a conversion joint, a pump body, an oil pipe, an oil pipe hanger, an oil production spool, a pump rod and a ground control unit, and the following steps are performed: The first step is to clean the wellbore; The second step is to insert the optical fiber through the slit at the top of the slit small-diameter oil pipe, and fix the optical fiber inside the lower end of the slit small-diameter oil pipe; The third step is to lower the slotted small diameter oil pipe into the predetermined position in the well; The fourth step is to connect the upper end of the slit small diameter oil pipe with the lower end of the conversion joint, the upper end of the conversion joint with the lower end of the pump body, the upper end of the pump body with the lower end of the oil pipe, and push the lower end of the slit small diameter oil pipe into the target position at the bottom of the well by lowering the oil pipe; The fifth step is to install a tubing hanger between the lower end of the oil production spool and the upper end of the oil pipe, and then set a through hole connecting the inside and the outside on the upper part of the tubing hanger, and finally pass the upper end of the optical fiber through the through hole into the tubing hanger and lead it out from the top screw hole of the oil production spool and connect it to the ground control unit; Step 6: Pass the lower end of the sucker rod through the oil production spool, the tubing hanger and the tubing from top to bottom in sequence and then insert it into the pump body; Step 7: After the well is shut down for a certain period of time, measure the formation background temperature in the well; Step 8: Start production and collect DAS / DTS data through optical fiber; In the ninth step, the DAS / DTS data is parsed by the ground control unit to obtain the output of a single cluster.

[0008] The following are further optimizations and / or improvements to the above technical solutions: In the third step, when the slit small diameter oil pipe drives the optical fiber into the well, the optical loss of the optical fiber is measured every 400 to 600 meters of the slit small diameter oil pipe. If the optical loss of the optical fiber is abnormal, the slit small diameter oil pipe is taken out and the optical fiber is checked. Otherwise, the slit small diameter oil pipe is used to drive the optical fiber to continue to be lowered into the well.

[0009] In the seventh step above, after the well is shut in for 48 hours, the ground control unit measures the formation background temperature in the well through DAS / DTS data collected by optical fiber.

[0010] In the second step above, the length of the slotted small-diameter tubing is the distance between the lower end of the pump body and the artificial bottom hole. A suspension joint is fixed to the inner side of the lower end of the slotted small-diameter tubing, and the suspension joint is fixedly connected to the lower end of the optical fiber. In the fifth step, a sealing plug is installed between the outer side of the upper part of the optical fiber and the set screw hole of the production manifold.

[0011] The second step above further includes fixedly installing a plurality of first clamps at intervals along the length on the outer side of the slotted small-diameter tubing at each slotted position. In the fourth step, before lowering the tubing, a plurality of second clamps are fixedly installed at intervals along the length on the outer side of the cable-laid optical fiber at the position between the uppermost slot and the through hole.

[0012] The present invention achieves the purpose of monitoring the fluid production profile of multi-stage fracturing in heavy oil rod-pumped horizontal wells, solves the problems that the flow meters in heavy oil wells are not applicable and it is difficult to test the well with a pump tubing string in the well. Through accurate monitoring of the fluid production profile, the fluid production contribution rate of each cluster of reservoirs and the fracturing effect are accurately understood, providing an important basis for reservoir understanding and optimization of the fracturing transformation plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] APPENDIX Figure 1 It is the front view sectional structure schematic diagram of Embodiment 1 to Embodiment 5 of the present invention.

[0014] The codes in the drawings are respectively: 1 is the optical fiber, 2 is the slotted small-diameter tubing, 3 is the adapter, 4 is the pump body, 5 is the tubing, 6 is the tubing hanger, 7 is the production manifold, 8 is the sucker rod, 9 is the ground control unit, 10 is the slot, 11 is the through hole, 12 is the suspension joint, 13 is the sealing plug, 14 is the first clamp, and 15 is the second clamp. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present invention is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical solutions of the present invention and the actual situation.

[0016] In the present invention, for the convenience of description, the description of the relative position relationship of each component is based on the layout mode of the attached drawings of the specification. For example, the position relationships such as front, rear, upper, lower, left, and right are determined according to the layout direction of the attached drawings of the specification. Figure 1 The position relationships such as front, rear, upper, lower, left, and right are determined according to the layout direction of the attached drawings of the specification.

[0017] The present invention will be further described below in conjunction with the embodiments and the drawings: Embodiment 1: As shown in the appendix Figure 1 The optical fiber monitoring fluid production profile test system for heavy oil rod-pumped horizontal wells includes an optical fiber 1, a slotted small-diameter tubing 2, an adapter 3, a pump body 4, a tubing 5, a tubing hanger 6, a production manifold 7, a sucker rod 8, and a ground control unit 9, and is carried out according to the following steps: The first step is to clean the wellbore; In the second step, insert the optical fiber 1 through the slit 10 at the uppermost part of the small-diameter slotted tubing 2, and fix the optical fiber 1 inside the lower end of the small-diameter slotted tubing 2. In the third step, lower the small-diameter slotted tubing 2 to the predetermined position in the well. In the fourth step, at the wellhead, connect the upper end of the small-diameter slotted tubing 2 to the lower end of the adapter 3, connect the upper end of the adapter 3 to the lower end of the pump body 4, connect the upper end of the pump body 4 to the lower end of the tubing 5, and lower the tubing 5 to push the lower end of the small-diameter slotted tubing 2 to the target position at the bottom of the well. In the fifth step, install a tubing hanger 6 between the lower end of the production cross-over 7 and the upper end of the tubing 5. Then, set a through-hole 11 that is internally and externally connected above the tubing hanger 6. Finally, pass the upper end of the optical fiber 1 through the through-hole 11 into the tubing hanger 6 and lead it out from the set screw hole of the production cross-over 7 and connect it to the ground control unit 9. In the sixth step, pass the lower end of the sucker rod 8 through the production cross-over 7, the tubing hanger 6, and the tubing 5 from top to bottom in sequence and then sleeve it inside the pump body 4. In the seventh step, measure the background temperature of the formation in the well after shutting in the well for a certain period of time. In the eighth step, open the well for production and collect DAS / DTS data through the optical fiber 1. In the ninth step, analyze the DAS / DTS data through the ground control unit 9 to obtain the production situation of a single cluster.

[0018] As required, both the optical fiber 1 and the ground control unit 9 are existing well-known technologies. The present invention achieves the purpose of monitoring the liquid production profile of multi-stage fracturing in heavy oil rod-pumped horizontal wells, solves the problems that the flowmeter in heavy oil wells is not applicable and it is difficult to test the well with a pump tubing string in the well. By collecting DAS / DTS data through the optical fiber 1, the liquid production profile is accurately monitored, and the liquid production contribution rate of each cluster of reservoirs and the fracturing effect are accurately understood, providing an important basis for reservoir understanding and optimization of the fracturing transformation plan.

[0019] According to actual needs, the above-mentioned optical fiber monitoring liquid production profile test system for heavy oil rod-pumped horizontal wells can be further optimized and / or improved: Embodiment 2: As an optimization of the above embodiment, as shown in the appendix Figure 1 When the small-diameter slotted tubing 2 drives the optical fiber 1 to be lowered into the well, as shown, every time the small-diameter slotted tubing 2 is lowered by 400 to 600 meters, measure the optical loss of the optical fiber 1. If the optical loss of the optical fiber 1 is abnormal, then pull out the small-diameter slotted tubing 2 and check the optical fiber 1. Otherwise, continue to lower the small-diameter slotted tubing 2 with the optical fiber 1 into the well. When the small-diameter slotted tubing 2 drives the optical fiber 1 to be lowered into the well, measure the optical loss of the optical fiber 1 every time the small-diameter slotted tubing 2 is lowered by 500 meters. This can timely detect the failure of the optical fiber 1 and avoid the phenomenon of rework caused by re-pulling out the tubing string after the optical fiber 1 fails after being lowered into the artificial bottom hole with the small-diameter slotted tubing 2.

[0020] Example 3: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, in the seventh step, after shutting in the well for 48 hours, the ground control unit 9 measures the background temperature of the formation in the well through the DAS / DTS data collected by the optical fiber 1. After shutting in the well for 48 hours, the background temperature of the formation in the well is more stable, so that the measurement of the background temperature of the formation in the well is more accurate, facilitating the subsequent data analysis.

[0021] Example 4: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, in the second step, the length of the slotted small-diameter tubing 2 is the distance between the lower end of the pump body 4 and the artificial bottom hole. A suspension joint 12 is fixedly installed inside the lower end of the slotted small-diameter tubing 2, and the suspension joint 12 is fixedly connected to the lower end of the optical fiber 1; in the fifth step, a sealing plug 13 is installed between the outer side of the upper part of the optical fiber 1 and the set screw hole of the production cross 7. According to requirements, the suspension joint 12 is a known technology in the art, such as an optical fiber joint. By setting the suspension joint 12, it can prevent the optical fiber 1 from being displaced and affecting data collection. By setting the sealing plug 13, the sealing between the set screw hole of the production cross 7 and the optical fiber can be achieved, avoiding affecting the production process.

[0022] Example 5: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, the second step further includes fixedly installing a plurality of first clamps 14 at intervals along the length direction on the outer side of the slotted small-diameter tubing 2 at each slotted position 10; in the fourth step, before lowering the tubing 5, a plurality of second clamps 15 are fixedly installed at intervals along the length direction on the outer side of the optical fiber 1 at the position between the uppermost slot 10 and the through-hole 11. A plurality of slots 10 are arranged at intervals along the length direction on the outer side of the slotted small-diameter tubing 2, and the distance between two adjacent first clamps 14 is 5 meters. By setting the first clamps 14, it can avoid the phenomenon that the optical fiber 1 fails after passing through the slot 10 during data collection. The plurality of second clamps 15 are respectively fixedly installed together with the adapter 3, the pump body 4, and the outer side of the tubing 5. In this way, the optical fiber 1 can be fixed on the outer side of the adapter 3, the outer side of the pump body 4, and the outer side of the tubing 5, which can suspend the optical fiber 1 and avoid the phenomenon of the optical fiber 1 breaking. When lowering the tubing 5 to push the slotted small-diameter tubing 2 forward to the bottom of the well, install the second clamps 15 while lowering the tubing.

[0023] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effects. Non-essential technical features can be increased or decreased according to actual needs to meet the requirements of different situations.

[0024] The usage process of the best embodiment of the present invention: First step: For the heavy oil multi-stage fractured horizontal well J09 with a vertical depth of 1700 m and a horizontal section length of 800 m, after perforating and bridge plugging for staged fracturing transformation, liquid withdrawal and trial production are carried out. Before the production profile test, coiled tubing is used to drill and mill the bridge plug and flush the wellbore clean. Second step: Prepare a slotted small-diameter tubing 2 with a length of 900 m and an outer diameter of 38 mm, an optical fiber 1 composed of 2 single-mode optical fibers and 2 multi-mode optical fibers with a length of 3000 m, lower the pump body 4 to a depth of 1600 m, and prepare a tubing 5 with a length of 1600 m and an outer diameter of 73 mm. There is a suspension joint 12 at the lower end of the slotted small-diameter tubing 2. After passing the optical fiber 1 through the slot 10 at the uppermost part of the slotted small-diameter tubing 2, it is fixedly connected to the suspension joint 12, and a first clamp 14 is fixed every 5 m on the outside of the slotted small-diameter tubing 2. Third step: Lower the slotted small-diameter tubing 2 into the well. Every time the slotted small-diameter tubing 2 is lowered by 500 m, the optical loss of the optical fiber 1 is measured to be normal. Finally, lower the lower end of the slotted small-diameter tubing 2 to a predetermined position of 900 m in the well. Fourth step: Connect the upper end of the slotted small-diameter tubing 2 to the lower end of a 38 mm to 73 mm adapter 3, connect the upper end of the adapter 3 to the lower end of the pump body 4, connect the upper end of the pump body 4 to the lower end of the tubing 5 with an outer diameter of 73 mm. Along the length direction, a second clamp 15 is installed every 10 m on the outside of the optical fiber 1 at the position between the uppermost slot 10 and the through-hole 11. Fix the optical fiber 1 on the outside of the adapter 3, the pump body 4, and the tubing 5 from bottom to top in sequence. Lower the tubing 5 to push the lower end of the slotted small-diameter tubing 2 to the bottom target position. Fifth step: After lowering the tubing 5 to make the lower end of the slotted small-diameter tubing 2 reach the bottom target position, install a tubing hanger 6 between the lower end of the production cross 7 and the upper end of the tubing 5. The upper end of the optical fiber 1 passes through the through-hole 11 into the tubing hanger 6 and is led out through the top screw hole of the production cross 7 and then connected to the ground control unit 9. A sealing plug 13 is installed between the optical fiber 1 and the top screw hole of the production cross 7. Sixth step: Pass the lower end of the sucker rod 8 through the production cross 7, the tubing hanger 6, and the tubing 5 from top to bottom in sequence and then sleeve it into the pump body 4, and install the production wellhead. Seventh step: After shutting in the well for a certain period of time, measure the background temperature of the formation in the well; after shutting in the well for 48 hours, the ground control unit 9 collects DAS / DTS data through the optical fiber 1 to measure the background temperature of the formation in the well. The pumping unit produces at 30 m³ / day. After the oil content is stable, collect the optical fiber DAS / DTS data. Eighth step: Open the well for production. The pumping unit produces at 30 m³ / day. After the oil content is stable, collect the DAS / DTS data through the optical fiber 1. Ninth step: Analyze the DAS / DTS data through the ground control unit 9 to obtain the production situation of a single cluster.

Claims

1. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs, comprising an optical fiber, a slotted small-diameter tubing, a transition joint, a pump body, a tubing, a tubing hanger, a production cross, a sucker rod, and a ground control unit. It is characterized in that it is carried out according to the following steps: The first step is to clean the wellbore thoroughly. The second step is to insert the optical fiber through the slot at the top of the slotted small-diameter tubing and fix the optical fiber inside the lower end of the slotted small-diameter tubing. The third step is to lower the slotted small-diameter tubing to a predetermined position in the well. The fourth step is to connect the upper end of the slotted small-diameter tubing to the lower end of the transition joint, connect the upper end of the transition joint to the lower end of the pump body, connect the upper end of the pump body to the lower end of the tubing, and lower the tubing to push the lower end of the slotted small-diameter tubing to the target position at the bottom of the well. The fifth step is to install a tubing hanger between the lower end of the production cross and the upper end of the tubing, then set a through hole that is internally and externally connected above the tubing hanger, and finally pass the upper end of the optical fiber through the through hole into the tubing hanger and lead it out from the top screw hole of the production cross and connect it to the ground control unit. The sixth step is to pass the lower end of the sucker rod through the production cross, the tubing hanger, and the tubing from top to bottom and then sleeve it inside the pump body. The seventh step is to measure the background temperature of the formation in the well after shutting in the well for a certain period of time. The eighth step is to start production by opening the well and collect DAS / DTS data through the optical fiber. The ninth step is to analyze the DAS / DTS data through the ground control unit to obtain the production situation of a single cluster.

2. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs according to claim 1, it is characterized in that in the third step, when the slotted small-diameter tubing drives the optical fiber into the well, measure the optical loss of the optical fiber every 400 to 600 meters of the slotted small-diameter tubing lowered. If the optical loss of the optical fiber is abnormal, pull out the slotted small-diameter tubing to check the optical fiber. Otherwise, continue to lower the slotted small-diameter tubing with the optical fiber into the well.

3. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs according to claim 1 or 2, it is characterized in that in the seventh step, after shutting in the well for 48 hours, the ground control unit measures the background temperature of the formation in the well through the DAS / DTS data collected by the optical fiber.

4. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs according to claim 1 or 2, it is characterized in that in the second step, the length of the slotted small-diameter tubing is the distance between the lower end of the pump body and the artificial bottom hole. A suspension joint is fixed inside the lower end of the slotted small-diameter tubing, and the suspension joint is fixedly connected to the lower end of the optical fiber; in the fifth step, a sealing plug is installed between the outer side of the upper part of the optical fiber and the inner side of the top screw hole of the production cross.

5. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs according to claim 3, it is characterized in that in the second step, the length of the slotted small-diameter tubing is the distance between the lower end of the pump body and the artificial bottom hole. A suspension joint is fixed inside the lower end of the slotted small-diameter tubing, and the suspension joint is fixedly connected to the lower end of the optical fiber; in the fifth step, a sealing plug is installed between the outer side of the upper part of the optical fiber and the inner side of the top screw hole of the production cross.

6. A fiber optic monitoring liquid production profile test system for rod pumped horizontal wells in heavy oil reservoirs according to claim 1 or 2 or 5, it is characterized in that The second step further includes fixedly installing a plurality of first clamps at intervals along the length direction on the outer side of the slotted small-diameter tubing at each slotted position; in the fourth step, before lowering the tubing, a plurality of second clamps are fixedly installed at intervals along the length direction on the outer side of the cable-laid optical fiber at the position between the uppermost slot and the through hole.

7. A fiber optic monitoring liquid production profile test system for heavy oil rod pumped horizontal wells according to claim 3, characterized in that the second step further includes fixedly installing a plurality of first clamps at intervals along the length direction on the outer side of the slotted small-diameter tubing at each slotted position; in the fourth step, before lowering the tubing, a plurality of second clamps are fixedly installed at intervals along the length direction on the outer side of the cable-laid optical fiber at the position between the uppermost slot and the through hole.

8. A fiber optic monitoring liquid production profile test system for heavy oil rod pumped horizontal wells according to claim 4, characterized in that the second step further includes fixedly installing a plurality of first clamps at intervals along the length direction on the outer side of the slotted small-diameter tubing at each slotted position; in the fourth step, before lowering the tubing, a plurality of second clamps are fixedly installed at intervals along the length direction on the outer side of the cable-laid optical fiber at the position between the uppermost slot and the through hole.

Images