Gas well liquid production profile and underground television integrated test tubular column and test method

Abstract

The invention relates to the technical field of oil and gas well oil testing and production testing, in particular to a gas well liquid production profile and underground television integrated testing tubular column and a testing method.The gas well liquid production profile and underground television integrated testing tubular column comprises a photoelectric composite cable, a continuous oil pipe, a centralizer, a check valve, a light source and an underground television terminal, and the continuous oil pipe, the centralizer, the check valve, the light source and the underground television terminal are sequentially connected together from top to bottom; a plurality of circulating well washing nozzles are arranged on the outer side of the check valve at intervals, the lower end of the photoelectric composite cable sequentially penetrates through the coiled tubing, the centralizer and the check valve and then is connected with the light source and the underground television terminal, and the photoelectric composite cable can collect temperature data and sound data. The device is reasonable and compact in structure, collection of liquid production profile data and monitoring of the opening condition of each perforation cluster are completed through one test tubular column, and the problems that the construction period is long and the cost is high when gas well liquid production profile monitoring and underground television perforation monitoring after fracturing are conducted respectively are solved; and powerful guidance is provided for reservoir and fracturing effect evaluation and fracturing scheme optimization.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas well oil testing and production testing, and is a gas well production liquid profile and downhole television integrated test pipe string and a test method. Background Art

[0002] China is rich in low-permeability and shale oil and gas resources, which are expected to become important replacement resources. Pilot tests of low-permeability and shale oil and gas have been carried out in the Songliao Basin, Ordos, Junggar, and Sichuan Basins. It has been confirmed that multi-stage cluster volume fracturing of horizontal wells has become a key technology for improving EUR and efficient development. However, due to the strong heterogeneity of the reservoir, the production capacity after staged fracturing is very different. It is urgent to understand the production capacity and fracturing effect of each stage and cluster, so as to provide an important basis for fine classification of reservoirs, optimization of fracturing transformation schemes, and selection of layers for repeated fracturing.

[0003] The patent document with application number 201811193875.2 and titled "Horizontal Well Continuous Tubing Downhole TV Test String and Test Method" discloses: using a continuous tubing with an optical fiber cable, the upper end of the optical fiber cable is connected to a ground display instrument terminal, and the lower end of the optical fiber cable is connected to a downhole TV test terminal. The optical fiber plays a role in signal transmission, and the cable plays a role in providing power transmission. The horizontal well continuous tubing downhole TV test string can complete visual detection in the horizontal well section, and has the characteristics of simple operation and precise effect.

[0004] The patent document with application number CN201910640346.0 and titled "A production profile monitoring method based on distributed optical fiber sound monitoring and distributed optical fiber temperature monitoring" discloses: the sound signal reflected by the single-mode acoustic optical fiber and the temperature signal reflected by the multi-mode temperature-sensitive optical fiber are processed by the DTS / DAS injection and production well production profile interpretation module, and finally the real-time flow rate and water content of each production layer section of the injection and production well are obtained, which can complete "a single well operation to achieve full well section production profile testing".

[0005] The journal article titled "Analysis of Uniform Fracturing Degree of Multiple Clusters of Fractures Based on Perforation Imaging Monitoring" disclosed that: through the use of cable continuous tubing transportation, the degree of perforation abrasion is monitored using perforation imaging, and then the uniformity of fracturing of each cluster of fractures and the entry of proppant are analyzed, providing an important basis for optimizing the pumping program, reducing blasthole erosion, and improving the success rate of temporary plugging.

[0006] Post-fracturing perforation visualization monitoring and fluid production profile monitoring are two testing methods that can evaluate reservoirs and fracturing effects from different perspectives. The two processes have their own advantages. Among them, for gas well fluid production profile testing, distributed fiber optic monitoring has obvious advantages over array multi-probe testing technology. However, currently the visualization and fluid production profile monitoring processes are carried out separately, and the complementary advantages of the two technologies have not been achieved. Summary of the invention

[0007] The present invention provides a gas well production fluid profile and downhole television integrated test string and test method, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problems of long construction period and high cost in the existing separate monitoring of gas well production fluid profile and downhole television blasthole monitoring after fracturing.

[0008] One of the technical solutions of the present invention is achieved through the following measures: a gas well production liquid profile and downhole television integrated test string and test method, including an optoelectronic composite cable and a continuous oil pipe, a centralizer, a check valve, a light source and a downhole television terminal connected together from top to bottom, a plurality of circulating well washing nozzles are arranged at intervals on the outside of the check valve, the lower end of the optoelectronic composite cable passes through the continuous oil pipe, the centralizer, and the check valve in sequence and is connected to the light source and the downhole television terminal respectively, and the optoelectronic composite cable can collect temperature data and sound data.

[0009] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The above-mentioned optoelectronic composite cable may include at least three single-mode optical fibers and at least one multi-mode optical fiber, one of which is used to collect sound data, one of which is used to collect temperature data, and the other two single-mode optical fibers are respectively connected to the light source and the downhole television terminal.

[0010] The second technical solution of the present invention is achieved by the following measures: A testing method comprises the following steps: The first step is to clean the sand and debris in the wellbore and then shut down the well; The second step is to assemble the gas well production profile and the downhole TV integrated test string, and then test whether the gas well production profile and the downhole TV integrated test string are working normally. If yes, proceed to the third step. If not, check the gas well production profile and the downhole TV integrated test string; The third step is to run the gas well production profile and downhole TV integrated test string in the shut-in state. After running 150 to 250 meters, check the gas well production profile and downhole TV integrated test string. If normal, continue running; if abnormal, take it out for later inspection; Step 4: After the gas well production profile and downhole TV integrated test string is lowered to 20 to 30 meters above the perforation cluster, the lowering speed is reduced, the ground data acquisition equipment is connected to the photoelectric composite cable, and the changes in the perforation holes are monitored using the downhole TV terminal. After completing the monitoring of all perforation clusters, the connection between the ground data acquisition equipment and the photoelectric composite cable is disconnected; The fifth step is to use the photoelectric composite cable to monitor the formation temperature when the well is shut in. When the formation temperature is stable, the well is opened for production. Step 6: Select 2 to 3 nozzles for production. When the production is stable under each production system, collect temperature data and sound data. After receiving qualified temperature data and sound data, propose the gas well production profile and downhole TV integrated test string. The seventh step is to analyze the abrasion of the holes of each perforation cluster according to the opening status of each perforation cluster monitored by the downhole TV terminal, and evaluate the crack initiation law of each perforation cluster and the uniformity of the opening of each perforation cluster under different fracturing pumping parameters. According to the temperature data and sound data collected by the optoelectronic composite cable, combined with the opening status of each perforation cluster monitored by the downhole TV terminal, the interpretation results of the fluid production profile are obtained.

[0011] The following is a further optimization and / or improvement of the second technical solution of the above invention: In the sixth step, when the output is stable under each production system, one of the single-mode optical fibers of the optoelectronic composite cable collects temperature data, and one of the multi-mode optical fibers of the composite cable collects sound data, and then the qualified temperature data and sound data are recorded.

[0012] The second step of testing the gas well production profile and whether the downhole TV integrated test string is working properly includes: testing whether the optical fiber loss of the optoelectronic composite cable is normal; testing whether the light source is normal; and testing whether the downhole TV terminal monitors the opening status of each perforation cluster clearly.

[0013] The second step of testing the gas well production profile and the downhole television integrated test string to see if it is working properly also includes: pumping clean water into the coiled tubing at a displacement of 44 to 55 liters / minute to test whether the circulating well washing nozzle is working properly.

[0014] The inspection of the gas well production profile and the downhole television integrated test string in the third step includes: testing whether the optical fiber loss of the optoelectronic composite cable is normal; and testing whether the light source and the downhole television terminal can clearly observe the casing coupling.

[0015] In the fourth step, if the area in front of the downhole TV terminal is blurred and the hole is covered with sand, clean water is pumped into the coiled tubing and water is sprayed from the circulating well washing nozzle for cleaning.

[0016] The present invention has a reasonable and compact structure and is easy to use. It has been applied and verified in multiple blocks such as deep shale gas. It realizes the collection of production profile data and the monitoring of the opening status of each perforation cluster in one test string, and solves the problem of long construction period and high cost for separately monitoring the production profile of gas wells and monitoring the downhole TV perforation holes after fracturing. It improves the accuracy of the interpretation results and provides powerful guidance for reservoir and fracturing effect evaluation and fracturing scheme optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 This is a schematic diagram of the front cross-sectional structure of the first embodiment when in use.

[0018] The codes in the attached drawings are: 1 is a photoelectric composite cable, 2 is a continuous oil pipe, 3 is a centralizer, 4 is a check valve, 5 is a light source, 6 is a downhole TV terminal, and 7 is a circulating well washing nozzle. DETAILED DESCRIPTION

[0019] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0020] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0021] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As shown in the attached Figure 1 As shown, the gas well production liquid profile and downhole television integrated test string includes an optoelectronic composite cable 1 and a continuous oil pipe 2, a centralizer 3, a check valve 4, a light source 5 and a downhole television terminal 6 connected together from top to bottom. A plurality of circulating well washing nozzles 7 are arranged at intervals outside the check valve 4. The lower end of the optoelectronic composite cable 1 passes through the continuous oil pipe 2, the centralizer 3, and the check valve 4 in sequence and is respectively connected to the light source 5 and the downhole television terminal 6, and the optoelectronic composite cable 1 can collect temperature data and sound data.

[0022] According to the requirements, the light source 5 is an existing well-known LED light source, and the downhole TV terminal 6 is an existing well-known downhole imaging device. The present invention has been applied and verified in multiple blocks such as deep shale gas, and has achieved the collection of production profile data and the monitoring of the opening status of each perforation cluster in one test string, solving the problem of long construction period and high cost for monitoring the production profile of gas wells and monitoring the perforation holes of downhole TV after fracturing, improving the accuracy of the interpretation results, and providing powerful guidance for reservoir and fracturing effect evaluation and fracturing scheme optimization.

[0023] The above-mentioned gas well production profile and downhole TV integrated test string can be further optimized and / or improved according to actual needs: Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the optoelectronic composite cable 1 includes at least three single-mode optical fibers and at least one multi-mode optical fiber, one of which is used to collect sound data, one of which is used to collect temperature data, and the other two single-mode optical fibers are connected to the light source 5 and the downhole television terminal 6 respectively.

[0024] According to the requirements, the optoelectronic composite cable 1 also includes a cable, which has at least two core cables, one of which is connected to the light source 5 for supplying power to the light source 5; one of which is connected to the downhole TV terminal 6 for supplying power to the downhole TV terminal 6. The single-mode optical fiber is an existing well-known distributed optical fiber temperature sensing system (DTS), and the multi-mode optical fiber is an existing well-known distributed optical fiber acoustic sensing system (DAS), so that accurate data can be obtained underground.

[0025] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the test method comprises the following steps: The first step is to clean the sand and debris in the wellbore and then shut down the well; The second step is to assemble the gas well production profile and the downhole TV integrated test string, and then test whether the gas well production profile and the downhole TV integrated test string are working normally. If yes, proceed to the third step. If not, check the gas well production profile and the downhole TV integrated test string; The third step is to run the gas well production profile and downhole TV integrated test string in the shut-in state. After running 150 to 250 meters, check the gas well production profile and downhole TV integrated test string. If normal, continue running; if abnormal, take it out for later inspection; Step 4: After the gas well production profile and downhole television integrated test string are lowered to 20 to 30 meters above the perforation cluster, the lowering speed is reduced, the ground data acquisition equipment is connected to the photoelectric composite cable 1, and the perforation hole changes are monitored by the downhole television terminal 6. After the monitoring of all perforation clusters is completed, the connection between the ground data acquisition equipment and the photoelectric composite cable 1 is disconnected; Step 5: Use the photoelectric composite cable 1 to monitor the formation temperature in the well-shut state, and start production when the formation temperature is stable; Step 6: Select 2 to 3 nozzles for production. When the production is stable under each production system, collect temperature data and sound data. After receiving qualified temperature data and sound data, propose the gas well production profile and downhole TV integrated test string. The seventh step is to analyze the abrasion of the holes of each perforation cluster according to the opening status of each perforation cluster monitored by the downhole TV terminal 6, and evaluate the crack initiation law of each perforation cluster and the uniformity of the opening of each perforation cluster under different fracturing pumping parameters; based on the temperature data and sound data collected by the optoelectronic composite cable 1, combined with the opening status of each perforation cluster monitored by the downhole TV terminal 6, obtain the interpretation results of the fluid production profile.

[0026] In this way, the interpretation results of the liquid production profile can reflect the main contribution sections of gas production at the toe and heel ends, optimize the fracturing scheme for reservoirs with poor physical properties and oil and gas content, improve the reservoir utilization rate, and provide powerful guidance for reservoir and fracturing effect evaluation and fracturing scheme optimization.

[0027] The above test method can be further optimized and / or improved according to actual needs: Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, in the sixth step, when the output is stable under each production system, one of the single-mode optical fibers of the optoelectronic composite cable 1 collects temperature data, and one of the multi-mode optical fibers of the composite cable collects sound data, and then the qualified temperature data and sound data are recorded.

[0028] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the second step of testing the gas well production profile and the downhole TV integrated test string to see if they are working properly includes: testing whether the optical fiber loss of the photoelectric composite cable 1 is normal; testing whether the light source 5 is normal; and testing whether the downhole TV terminal 6 monitors the opening of each perforation cluster to see if it is clear. This can timely detect abnormalities in the gas well production profile and the downhole TV integrated test string, avoid monitoring failures caused by abnormalities in the well, and reduce monitoring costs.

[0029] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the second step of testing the gas well production profile and whether the downhole TV integrated test string is working properly also includes: pumping clean water into the coiled tubing 2 at a displacement of 44 to 55 liters / minute to test whether the circulating well-washing nozzle 7 is working properly. This can ensure that the circulating well-washing nozzle 7 can work properly in the wellbore, and can timely flush the places where the downhole TV terminal 6 is not clearly photographed, so that the wellbore can be clearly observed.

[0030] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the third step of checking the gas well production profile and the downhole TV integrated test string includes: testing whether the optical fiber loss of the photoelectric composite cable 1 is normal; testing whether the light source 5 and the downhole TV terminal 6 can clearly observe the casing collar. In this way, the abnormal conditions of the gas well production profile and the downhole TV integrated test string can be discovered in time, and the phenomenon of monitoring failure caused by abnormalities in the well can be avoided, which can reduce the monitoring cost.

[0031] Embodiment 8: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, in the fourth step, if the area in front of the downhole TV terminal 6 is blurred and the hole is covered with sand, clean water is pumped into the coiled tubing 2, and water is sprayed out from the circulating well washing nozzle 7 for cleaning. This can ensure that the area in front of the downhole TV terminal 6 is clean, which is convenient for the downhole TV terminal 6 to monitor the wellbore.

[0032] The specific process of the test method of this embodiment is as follows: The first step is to use a perforated bridge plug to drill and grind the bridge plug and flush the well clean. The wellbore is filled with clean water and the well is shut in.

[0033] The second step is to assemble a 6,600-meter-long gas well production profile and downhole television integrated test string. The optoelectronic composite cable 1 passed through the coiled tubing 2 includes a 3-core cable and 6 optical fibers. Among the 6 optical fibers, 2 are multi-mode optical fibers, and the other 4 are single-mode optical fibers. One of the 2 multi-mode optical fibers is used to collect sound data, and the other multi-mode optical fiber is spare. Two of the 4 single-mode optical fibers are connected to the light source 5 and the downhole television terminal 6 respectively, and the other single-mode optical fiber collects temperature data. The remaining single-mode optical fiber is spare. The 3-core electric cable 1 is used to collect sound data, and the other single-mode optical fiber is used to collect sound data. The first core cable in the cable is connected to the light source 5, the second core cable is connected to the downhole TV terminal 6, and the third core cable is reserved. After the ground data acquisition equipment is connected to the photoelectric composite cable 1, the optical fiber loss of the photoelectric composite cable 1 is tested to see if it is normal; the light source 5 is tested to see if it is normal; the downhole TV terminal 6 is tested to see if the opening of each perforation cluster is clear; clean water is pumped into the coiled tubing 2 at a displacement of 44 to 55 liters / minute to test whether the circulating well washing nozzle 7 is normal; the next step is carried out after the gas well production profile and the downhole TV integrated test string are working normally; The third step is to lower the gas well production profile and downhole TV integrated test string into the well under the shut-in state. After lowering 200 meters, test whether the optical fiber loss of the photoelectric composite cable 1 is normal, and then continue to lower it to test whether the light source 5 and the downhole TV terminal 6 can clearly observe the casing coupling. After the gas well production profile and the downhole TV integrated test string are normal, continue to lower it; Step 4: After the gas well production profile and downhole TV integrated test string is lowered to 20 meters above the 23rd perforation cluster (3890-3892 meters), it is lowered at a speed of 3 meters per minute. When the lower end of the gas well production profile and downhole TV integrated test string reaches the 23rd perforation cluster, it is lowered at a speed of 1 meter per minute to monitor the changes in the perforation holes of the 23rd perforation cluster. After the monitoring of the 23rd perforation cluster was completed, the gas well production profile and downhole TV integrated test string continued to be lowered at a speed of 3 meters per minute. When it reached the 22nd perforation cluster (4000-4002 meters), it was lowered at a speed of 1 meter per minute and the changes in the perforation holes of the 22nd perforation cluster were monitored. When the 18th perforation cluster is monitored, the bottom of the front casing is found to have sand covering the perforation holes through the downhole TV terminal 6, and the surface pump is started to pump clean water into the coiled tubing 2 at a displacement of 50 liters / minute. The downhole circulating well washing nozzle 7 sprays water to wash the sand, and then continues monitoring. After completing the monitoring of all perforation clusters, the connection between the ground data acquisition equipment and the optoelectronic composite cable is disconnected; The fifth step is to connect the ground data acquisition equipment to the single-mode optical fiber used to collect temperature information to monitor the formation temperature when the well is shut in. After the well is shut in for 36 hours, the formation temperature stabilizes and the well is opened for production.

[0034] Step 6: Select 4mm, 5mm, and 6mm nozzles for production respectively. Produce for 12 hours under each production system. When the output is stable, record qualified temperature and sound data. After the monitoring is completed, propose the gas well production profile and downhole TV integrated test string; Step 7. According to the opening status of each perforation cluster monitored by the downhole TV terminal 6, 70% of the holes in Well X1707 have proppant entering. At the toe and heel ends, the degree of cracking is uniform and good, the degree of hole abrasion is 20%-270%, and the average value is 75%. The 12th, 13th, and 14th perforation clusters with high shale content have low hole abrasion and less proppant entering. The interpretation results of the production profile show that the toe and heel ends are the main contribution sections for gas production. The 12th, 13th, and 14th perforation clusters with high shale content have a low contribution rate to gas production. The logging and well logging data interpretation of the 12th, 13th, and 14th perforation clusters show that the physical properties and oil and gas content are poor, the degree of fracturing transformation is low, and the production capacity improvement effect is poor. This type of reservoir should be avoided during geo-steering drilling to increase the drilling rate of high-quality reservoirs. At the same time, for reservoirs with poor physical properties and oil and gas content, it is necessary to continuously optimize the fracturing plan to improve the reservoir utilization rate.

[0035] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A gas well production profile and downhole television integrated test string, characterized in that The invention comprises a photoelectric composite cable and a continuous tubing, a centralizer, a check valve, a light source and a downhole television terminal which are sequentially connected from top to bottom. A plurality of circulating well-washing nozzles are arranged at intervals on the outside of the check valve. The lower end of the photoelectric composite cable sequentially passes through the continuous tubing, the centralizer and the check valve and is respectively connected to the light source and the downhole television terminal. The photoelectric composite cable can collect temperature data and sound data.

2. The gas well production profile and downhole television integrated test string according to claim 1, characterized in that The optoelectronic composite cable includes at least three single-mode optical fibers and at least one multi-mode optical fiber, one of which is used to collect sound data, one of which is used to collect temperature data, and the other two single-mode optical fibers are respectively connected to the light source and the downhole television terminal.

3. A testing method using the gas well production liquid profile and downhole television integrated testing string according to claim 1 or 2, characterized in that The steps include: The first step is to clean the sand and debris in the wellbore and then shut down the well; The second step is to assemble the gas well production profile and the downhole TV integrated test string, and then test whether the gas well production profile and the downhole TV integrated test string are working normally. If yes, proceed to the third step. If not, check the gas well production profile and the downhole TV integrated test string; The third step is to run the gas well production profile and downhole TV integrated test string in the shut-in state. After running 150 to 250 meters, check the gas well production profile and downhole TV integrated test string. If normal, continue running; if abnormal, take it out for later inspection; Step 4: After the gas well production profile and downhole TV integrated test string is lowered to 20 to 30 meters above the perforation cluster, the lowering speed is reduced, the ground data acquisition equipment is connected to the photoelectric composite cable, and the changes in the perforation holes are monitored using the downhole TV terminal. After completing the monitoring of all perforation clusters, the connection between the ground data acquisition equipment and the photoelectric composite cable is disconnected; The fifth step is to use the photoelectric composite cable to monitor the formation temperature when the well is shut in. When the formation temperature is stable, the well is opened for production. Step 6: Select 2 to 3 nozzles for production. When the production is stable under each production system, collect temperature data and sound data. After receiving qualified temperature data and sound data, propose the gas well production profile and downhole TV integrated test string. Step 7: According to the opening status of each perforation cluster monitored by the downhole TV terminal, the abrasion of each perforation cluster is analyzed, and the crack initiation law of each perforation cluster and the uniformity of the opening of each perforation cluster under different fracturing pumping parameters are evaluated; The interpretation results of the fluid production profile are obtained based on the temperature and sound data collected by the optoelectronic composite cable and the opening status of each perforation cluster monitored by the downhole TV terminal.

4. The testing method according to claim 3, characterized in that In the sixth step, when the output is stable under each production system, one of the single-mode optical fibers of the optoelectronic composite cable collects temperature data, and one of the multi-mode optical fibers of the composite cable collects sound data, and then the qualified temperature data and sound data are recorded.

5. The test method according to claim 3 or 4, characterized in that The second step of testing the gas well production profile and whether the downhole TV integrated test string is working properly includes: testing whether the optical fiber loss of the optoelectronic composite cable is normal; testing whether the light source is normal; and testing whether the downhole TV terminal monitors the opening status of each perforation cluster clearly.

6. The testing method according to claim 5, characterized in that The second step of testing the gas well production profile and the downhole TV integrated test string to see if it is working properly also includes: pumping clean water into the coiled tubing at a displacement of 44 to 55 liters / minute to test whether the circulating well washing nozzle is normal.

7. The test method according to claim 3, 4 or 6, characterized in that In the third step, the gas well production profile and the downhole TV integrated test string are inspected, including: testing whether the optical fiber loss of the optoelectronic composite cable is normal; testing whether the light source and the downhole TV terminal can clearly observe the casing coupling.

8. The testing method according to claim 5, characterized in that In the third step, the gas well production profile and the downhole TV integrated test string are inspected, including: testing whether the optical fiber loss of the optoelectronic composite cable is normal; testing whether the light source and the downhole TV terminal can clearly observe the casing coupling.

9. The test method according to claim 3 or 4 or 6 or 8, characterized in that In the fourth step, if the area in front of the downhole TV terminal is blurred and the hole is covered with sand, clean water is pumped into the coiled tubing and water is sprayed out from the circulating well washing nozzle for cleaning.

10. The testing method according to claim 5, characterized in that In the fourth step, if the area in front of the downhole TV terminal is blurred and the hole is covered with sand, clean water is pumped into the coiled tubing and water is sprayed out from the circulating well washing nozzle for cleaning.

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