Method for determining pump inspection reason of oil well and treatment method

Abstract

The present application relates to a kind of determining oil well pump inspection reason and treatment method, comprising the following steps: S1, determining the reason of oil well pump inspection, the reason includes leakage, tubing leakage or pumping pump fixed valve movement trajectory and pumping machine stroke, stroke is not coordinated;S2, for the reason of oil well pump inspection, determine the oil well treatment method;The method of the present application is applied in 67 oil wells in recent 5 years, 54 oil wells are exempted from pump inspection operation;Oil well needs 50,000 yuan each time pump inspection operation, from no liquid to pump inspection operation to restore normal daily oil production (daily liquid production minus daily water production) needs 6-7 days, the average daily oil production of oil well is calculated as 3.4 tons, and the crude oil production is increased by 20.4 tons-23.8 tons.

Description

Technical Field

[0001] This invention belongs to the field of oil production engineering technology, and in particular relates to a method for determining the cause of pump inspection in oil wells and a method for remediation. Background Technology

[0002] Pump inspection is a routine task in oilfield development, and determining and analyzing the causes of pump inspection is one of the important tasks of technicians.

[0003] Liu Gang's article, "Reasons for Oil Well Pump Inspection and Measures to Extend the Inspection Cycle," published in *Chemical Engineering & Equipment* in January 2021, states that with the increasing oilfield development activities and the continuous and stable acquisition of oil and gas resources, strict requirements are placed on oil pump performance and inspection cycles. This article first analyzes the reasons for oil well pump inspections, and then focuses on exploring effective measures to extend the inspection cycle. The aim is to control oil production costs, increase the profit margins of oilfield enterprises, and lay a solid foundation for future pump inspection work.

[0004] Wu Xiaowen's article "Analysis of Causes and Countermeasures for Oil Well Pump Inspection Operations in Oilfields," published in *Chemical Engineering & Equipment* in January 2021, records that in actual production, the causes of oil well pump inspection operations include many factors such as unreasonable parameters, inappropriate rod and tubing selection, formation sand and wax production, downhole tool quality issues, and rod and tubing wear. Pump inspection not only affects crude oil production but also increases production costs and labor intensity. This article analyzes the causes of pump inspection operations in a certain oilfield in recent years, studies the influencing factors, analyzes the effectiveness of existing technical measures, and proposes technical countermeasures to extend the pump inspection cycle in the future.

[0005] Yuan Wei's article, "Causes and Countermeasures Affecting Oil Well Pump Inspection Cycles," published in the *Journal of Jianghan Petroleum Staff University* in July 2021, states that most crude oil production in the Jianghan area of ​​the Jianghan Oilfield has entered the secondary production stage, currently relying primarily on mechanical pumping for enhanced oil recovery. Due to the long service life of oil wells, changes in geological formations and engineering factors, the maintenance cycle for some wells has shortened. Pump inspection operations have increased operating costs and impacted production in the Jianghan area. To improve pump inspection cycles, based on the actual work conditions at the pump inspection site, and considering the different influencing factors, countermeasures include wax removal and prevention techniques, appropriate selection of sand control processes, prevention of sucker rod breakage, management of tubing and pump leakage, and refined injection-production management.

[0006] Chinese patent CN 110276493 A discloses a method, device, and storage medium for predicting the pump inspection cycle of an oil well. The method includes acquiring a sample dataset that affects the pump inspection cycle of an oil well, the sample dataset including multiple index data affecting the pump inspection cycle; determining multiple principal component data affecting the pump inspection cycle from the multiple index data in the sample dataset through principal component analysis; performing regression analysis on the multiple principal component data to obtain regression analysis results; and predicting the pump inspection cycle of the oil well based on the regression analysis results.

[0007] Chinese Patent CN 107798209 A discloses a method and apparatus for calculating the benchmark value of pump inspection cycle for oil pumping units. The method includes: forming basic parameter values ​​for analyzing the benchmark value of pump inspection cycle based on the one-time investment cost of the producing well, the daily maintenance cost of a single well, and the actual production data of the oil well; calculating the first oil well's break-even pump inspection cycle value based on the basic parameter values ​​of the oil well's pump inspection cycle analysis, using daily oil production as a variable; calculating the second oil well's break-even pump inspection cycle value based on the basic parameter values ​​of the oil well's pump inspection cycle analysis, using a fixed production cycle as a variable; and obtaining the oil well's benchmark value of pump inspection cycle based on the first and second oil well break-even pump inspection cycle values. The basic data of this invention mainly comes from the supporting model of the lifting process technology and the actual production situation of the oil well, ensuring its authenticity and reliability, objective and accurate calculation, and avoiding human error.

[0008] Chinese Patent CN 113987933 A discloses a method for predicting pump inspection cycles in oil wells based on a BP neural network algorithm. The method includes acquiring relevant production datasets; preprocessing the data; performing feature engineering; building a model based on the BP neural network algorithm and finding the optimal accuracy model for prediction; and finally predicting the pump inspection cycle using the model. This invention, by adopting the above technical solutions, can predict future pump inspection cycles based solely on the analysis of existing data. By leveraging the BP neural network, this invention can better discover hidden relationships between data points and predict pump inspection cycles more accurately than other algorithms, providing better decision-making services for oil well construction.

[0009] Chinese Patent CN 113869405 A discloses a method for predicting pump inspection cycles in oil wells based on the K-means algorithm. The method includes acquiring relevant production datasets; labeling; data preprocessing; feature engineering; building a model based on the K-means algorithm and finding the optimal accuracy model for prediction; and finally predicting the production status of daily production data through the model, thereby statistically determining the time between two production shutdowns, i.e., the pump inspection cycle. This invention, by adopting the above technical solutions, can predict whether pump inspection is needed based on existing real-time production status data monitoring, reducing additional system development costs, minimizing manpower and material resources, and avoiding the subjectivity of pump inspection personnel. This will have a significant impact on improving oilfield development efficiency.

[0010] In fact, the main causes of pump failures reflected on the dynamometer card include: pump leakage, tubing leakage, sucker rod breakage, sucker rod disengagement, floating valve cover breakage, sand jamming, and wax jamming. Most of these causes can be confirmed during the pump inspection process. However, some wells show pump and tubing leakage on the dynamometer card, and the well is no longer producing fluid, but the pump inspection does not reveal these causes, and no cause can be found. This has become a bottleneck technology restricting well management. Summary of the Invention

[0011] The purpose of this invention is to provide a method for determining the cause of oil well pump inspection and its remedial measures, thereby improving oil well management and saving on oil well pump inspection costs.

[0012] The technical problem solved by this invention is achieved through the following technical solution:

[0013] A method for determining the cause of oil well pump inspection and its remedial measures includes the following steps:

[0014] S1. Determine the cause of pump failure in the oil well. The cause may include pump leakage, tubing leakage, or incompatibility between the fixed valve movement trajectory of the oil pump and the stroke and frequency of the pumping unit.

[0015] S2. Determine the treatment method for oil wells based on the reasons for pump inspection.

[0016] Furthermore, the determination of the reason for the oil well pump inspection includes the following steps:

[0017] S101. The indicator diagram reflects the wellhead pressure at the wellhead due to pump or tubing leakage. If there is no pressure response within 5 minutes, proceed with pump inspection. If the pressure fluctuates between 0.1 MPa and 0.3 MPa within 5 minutes, pull the plunger of the well pump out of the working barrel and remove 30m of water or clean water from the annulus using oilfield crude oil. 3 -50m 3 Heat to 65℃-70℃ for hot washing;

[0018] S102. After the oil well is hot-washed, put the plunger of the oil well pump back into the working barrel, start the pumping unit for 20-30 minutes, and pressurize the oil wellhead. If the pressurization pressure is between 0.1MPa and 0.3MPa after 5 minutes, the oil well is inspected.

[0019] S103. For wells undergoing pump testing, according to the engineering construction plan, remove the polished rod and 3-4 sucker rods from the well. Then, pressure test 10MPa-15MPa through the tubing. If the pressure drops to 0-5MPa within 15-30 minutes, the well is experiencing pump or tubing leakage. If the pressure drop is within 0.5MPa within 15-30 minutes, the well is not experiencing pump or tubing leakage, and it may be due to a mismatch between the fixed valve movement trajectory of the pump and the stroke and frequency of the pumping unit, resulting in no fluid output from the well.

[0020] Furthermore, the determination of the oil well treatment method based on the cause of the oil well pump inspection includes the following steps:

[0021] For wells with pump or tubing leaks, perform pump inspection operations until the wells are restored to normal production;

[0022] For oil wells where the problem is not pump leakage or tubing leakage, the following steps should be taken for well treatment:

[0023] S201. Lower the sucker rod and polished rod retrieved in step S103 into the oil well and adjust the anti-surge distance.

[0024] S202. Analyze the changes in daily fluid production in the 20-30 days before the well stops producing fluid; if the well production decreases by 10%-20%, adjust the well stroke frequency; if the well production decreases by 20%-40%, adjust the well stroke frequency or stroke length.

[0025] Furthermore, if the oil well production decreases by 10%-20%, the pumping frequency of the oil well should be adjusted from the normal production frequency to 1.5 times. The well should be started for 2-3 hours. If the dynamometer card shows normal operation, the well should continue production for 24-48 hours. If the dynamometer card is still normal, the pumping frequency should be adjusted back to the normal production frequency before the well stopped producing fluid. If the dynamometer card still reflects pump leakage or tubing leakage, pump inspection should be performed.

[0026] Furthermore, if the oil well production decreases by 20%-40%, the well pumping frequency should be adjusted from the normal production frequency to 1.5 times. After starting the pumping well for 2-3 hours, if the well indicator chart shows normal operation, continue production for 24-48 hours and if the indicator chart remains normal, adjust the well pumping frequency back to the normal production frequency before the well stopped producing fluid. If the well indicator chart still reflects pump or tubing leakage, then pump inspection should be performed.

[0027] Furthermore, if the oil well production decreases by 20%-40%, the oil well stroke rate is adjusted from the normal production stroke rate to 1.5 strokes. The well is started pumping for 2-3 hours. If the oil well dynamometer shows insufficient fluid supply, the oil well stroke rate is reduced by one level, and the oil well continues to produce. If the oil well dynamometer still reflects pump leakage or tubing leakage, pump inspection is carried out.

[0028] The advantages and positive effects of this invention are:

[0029] The method of this invention has been applied to 67 oil wells in the past 5 years, eliminating the need for pump inspection operations in 54 of them. Each pump inspection operation costs 50,000 yuan, and it takes 6-7 days for an oil well to return to normal daily oil production (daily liquid production minus daily water production) after pump inspection. Assuming an average daily oil production of 3.4 tons, this would increase crude oil production by 20.4-23.8 tons. Detailed Implementation

[0030] First, it should be noted that the specific structure, features, and advantages of the present invention will be described in detail below by way of examples. However, all descriptions are for illustrative purposes only and should not be construed as limiting the present invention in any way. Furthermore, any single technical feature described or implied in the various embodiments mentioned herein can still be arbitrarily combined or deleted among these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0032] Example 1

[0033] A method for determining the cause of oil well pump inspection and its remedial measures includes the following steps:

[0034] S1. Determine the cause of pump failure in the oil well. The cause may include pump leakage, tubing leakage, or incompatibility between the fixed valve movement trajectory of the oil pump and the stroke and frequency of the pumping unit.

[0035] S2. Determine the treatment method for oil wells based on the reasons for pump inspection.

[0036] Specifically, the reasons for determining the oil well pump inspection include the following steps:

[0037] S101. The indicator diagram reflects the wellhead pressure at the wellhead due to pump or tubing leakage. If there is no pressure response within 5 minutes, proceed with pump inspection. If the pressure fluctuates between 0.1 MPa and 0.3 MPa within 5 minutes, pull the plunger of the well pump out of the working barrel and remove 30m of water or clean water from the annulus using oilfield crude oil. 3 -50m 3 Heat to 65℃-70℃ for hot washing;

[0038] S102. After the oil well is hot-washed, put the plunger of the oil well pump back into the working barrel, start the pumping unit for 20-30 minutes, and pressurize the oil wellhead. If the pressurization pressure is between 0.1MPa and 0.3MPa after 5 minutes, the oil well is inspected.

[0039] S103. For wells undergoing pump testing, according to the engineering construction plan, remove the polished rod and 3-4 sucker rods from the well. Then, pressure test 10MPa-15MPa through the tubing. If the pressure drops to 0-5MPa within 15-30 minutes, the well is experiencing pump or tubing leakage. If the pressure drop is within 0.5MPa within 15-30 minutes, the well is not experiencing pump or tubing leakage, and it may be due to a mismatch between the fixed valve movement trajectory of the pump and the stroke and frequency of the pumping unit, resulting in no fluid output from the well.

[0040] Specifically, the determination of oil well treatment methods based on the causes of oil well pump inspection includes the following steps:

[0041] For wells with pump or tubing leaks, perform pump inspection operations until the wells are restored to normal production;

[0042] For oil wells where the problem is not pump leakage or tubing leakage, the following steps should be taken for well treatment:

[0043] S201. Lower the sucker rod and polished rod retrieved in step S103 into the oil well and adjust the anti-surge distance.

[0044] S202. Analyze the changes in daily fluid production in the 20-30 days before the well stops producing fluid; if the well production decreases by 10%-20%, adjust the well stroke frequency; if the well production decreases by 20%-40%, adjust the well stroke frequency or stroke length.

[0045] More specifically, if the oil well production decreases by 10%-20%, the well pumping frequency should be adjusted from the normal production frequency to 1.5 times. After starting the pumping well for 2-3 hours, if the well indicator chart shows normal operation, the well should continue production for 24-48 hours. If the indicator chart is still normal, the well pumping frequency should be adjusted back to the normal production frequency before the well stopped producing fluid. If the well indicator chart still reflects pump leakage or tubing leakage, pump inspection should be performed.

[0046] More specifically, if the oil well production decreases by 20%-40%, the well pumping frequency should be adjusted from the normal production frequency to 1.5 times. After starting the pumping well for 2-3 hours, if the well indicator chart shows normal operation, continue production for 24-48 hours. If the indicator chart remains normal, adjust the well pumping frequency back to the normal production frequency before the well stopped producing fluid. If the well indicator chart still reflects pump or tubing leakage, then pump inspection should be performed.

[0047] For oil well production reduction of 20%-40%, another remedial method is as follows: If oil well production decreases by 20%-40%, adjust the well stroke rate to 1.5 times, start pumping the well for 2-3 hours. If the well dynamometer card shows insufficient fluid supply, reduce the well stroke by one level (for example, adjust the stroke of a Type 14 pumping unit from 5.5m to 4.8m, and the pumping speed from 4.8m to 3.8m), and the well will continue production. If the well dynamometer card still reflects pump or tubing leakage, then pump inspection should be carried out.

[0048] The method for adjusting the stroke rate of oil wells is described in detail in the article "Development of Pumping Unit Stroke Rate Adjustment Tool" published by Liang Yueping et al. in Equipment Management and Maintenance in 2022, and is also well known to skilled or technical personnel.

[0049] The stroke of the pumping unit varies in size and increments depending on the model. This is detailed in the article "Analysis of the Historical Status and Development Trend of Pumping Units" published by Fang Renjie et al. in Drilling and Production Technology in March 2011, and is well known to those skilled in the art.

[0050] The method for adjusting the stroke of the pumping unit is detailed in the SY / T0408-2000 Pumping Unit Installation, Construction and Acceptance Specification, and is also recorded in Du Hongbo's article "Good People of China Pursuing the Dream of a Smart Oilfield" published in Trade Union Information in 2021; it is also well known to those skilled in the art.

[0051] Example 2

[0052] Application of the method in Example 1 in well XX-712

[0053] Step 1: Identification of pump leakage and tubing leakage in oil wells

[0054] ① The indicator diagram reflects the wellhead pressure at the wellhead due to pump or tubing leakage. If the pressure fluctuates between 0.1MPa and 0.3MPa over 5 minutes, the oil pump plunger is pulled out of the working barrel, and 30m of water or clean water is extracted from the annulus using oilfield crude oil. 3 -50m 3 Heat to 65℃-70℃ for hot washing;

[0055] ② After the oil well is hot-washed, put the plunger of the oil well pump back into the working barrel, start the pumping unit for 20-30 minutes, and pressurize the oil wellhead. The pressurization pressure fluctuates between 0.1MPa and 0.3MPa for 5 minutes. Then, perform pump inspection on the oil well.

[0056] ③ For oil wells undergoing pump inspection, according to the engineering construction plan, remove the polished rod and 3-4 sucker rods from the well. Then, use a 400-type pump truck to test the pressure at 10MPa-15MPa using crude oil or clean water extracted from the tubing. If the pressure drop is within 0.5MPa in 15-30 minutes, the oil well is unlikely to be leaking from the pump or tubing. It is more likely that the movement trajectory of the pump's fixed valve is not coordinated with the stroke and frequency of the pumping unit, causing the well to not produce fluid.

[0057] Step 2: Treatment of wells where the movement trajectory of the pumping unit's fixed valve is inconsistent with the stroke and frequency of the pumping unit.

[0058] ① Lower the 3-4 sucker rods and polished rods removed in step 1 ③ into the oil well and adjust the anti-surge distance;

[0059] ②Analyze the changes in daily fluid production from 20-30 days before the well stops producing fluid until the well stops producing fluid; if the well production decreases by 10%-20%, adjust the well flushing frequency;

[0060] ③ The oil well production decreased by 16.5%. The oil well pumping frequency was adjusted from 3.0 times to 1.5 times. After starting the pumping well for 2-3 hours, the oil well dynamometer was working normally. The oil well continued to produce for 24-48 hours and the dynamometer was still normal. The oil well pumping frequency was adjusted back to 3.0 times before the oil well stopped producing fluid, and the oil well production returned to normal.

[0061] After the application of the above-mentioned XX-712 well, the pump inspection operation cost was reduced by 50,000 yuan, the well occupation time for pump inspection was eliminated by 6 days, the daily oil production was 3.7 tons, and the crude oil production was increased by 22.2 tons.

[0062] Example 3:

[0063] Application of the method described in the embodiments in well XX-69

[0064] Step 1: Identification of pump leakage and tubing leakage in oil wells

[0065] ① The indicator diagram reflects the wellhead pressure at the wellhead due to pump or tubing leakage. If the pressure fluctuates between 0.1MPa and 0.3MPa over 5 minutes, the oil pump plunger is pulled out of the working barrel, and 30m of water or clean water is extracted from the annulus using oilfield crude oil. 3 -50m 3 Heat to 65℃-70℃ for hot washing;

[0066] ② After the oil well is hot-washed, put the plunger of the oil well pump back into the working barrel, start the pumping unit for 20-30 minutes, and pressurize the oil wellhead. The pressurization pressure fluctuates between 0.1MPa and 0.3MPa for 5 minutes. Then, perform pump inspection on the oil well.

[0067] ③ For oil wells undergoing pump inspection, according to the engineering construction plan, remove the polished rod and 3-4 sucker rods from the well. Then, use a 400-type pump truck to test the pressure at 10MPa-15MPa using crude oil or clean water from the tubing. If the pressure drop is 0.3MPa within 15-30 minutes, the oil well is unlikely to have pump or tubing leakage. It is more likely that the movement trajectory of the pump's fixed valve is not coordinated with the stroke and frequency of the pumping unit, causing the well to not produce fluid.

[0068] Step 2: Treatment of wells where the movement trajectory of the pumping unit's fixed valve is inconsistent with the stroke and frequency of the pumping unit.

[0069] ① Lower the 3-4 sucker rods and polished rods removed in step 1 ③ into the oil well and adjust the anti-surge distance;

[0070] ② Analyze the changes in daily fluid production from 20-30 days before the well stops producing fluid until it stops producing fluid; if the well production decreases by 20%-40%, adjust the well stroke frequency or stroke.

[0071] ③ If the oil well production decreases by 20%-40%, the oil well stroke frequency is adjusted from 4.0 times to 1.5 times. If the oil well is started up for 2-3 hours and the fluid supply on the oil well indicator is insufficient, the oil well stroke is reduced by one level, from 5.5m to 4.8m, and the oil well continues to produce.

[0072] After the application of the XX-69 well mentioned above, the pump inspection operation cost was reduced by 50,000 yuan, the well occupation time for pump inspection was eliminated by 7 days, the daily oil production was 2.9 tons, and the crude oil production was increased by 20.3 tons.

[0073] The above embodiments have provided a detailed description of the present invention, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for determining the cause of pump failure in oil wells and for remedial measures, characterized in that, Includes the following steps: S1. Determine the cause of pump failure in the oil well. The cause may include pump leakage, tubing leakage, or incompatibility between the fixed valve movement trajectory of the oil pump and the stroke and frequency of the pumping unit. S2. Determine the treatment method for oil wells based on the reasons for pump inspection; The reasons for determining the oil well pump inspection include the following steps: S101. The indicator diagram reflects the wellhead pressure at the wellhead due to pump or tubing leakage. If there is no pressure response within 5 minutes, proceed with pump inspection. If the pressure fluctuates between 0.1 MPa and 0.3 MPa within 5 minutes, pull the plunger of the well pump out of the working barrel and remove 30m of water or clean water from the annulus using oilfield crude oil. 3 -50m 3 Heat to 65℃-70℃ for hot washing; S102. After the oil well is hot-washed, put the plunger of the oil well pump back into the working barrel, start the pumping unit for 20-30 minutes, and pressurize the oil wellhead. If the pressurization pressure is between 0.1MPa and 0.3MPa after 5 minutes, the oil well is inspected. S103. For oil wells undergoing pump inspection, according to the engineering construction plan, remove the polished rod and 3-4 sucker rods from the well. Then, pressure test 10MPa-15MPa through the tubing. If the pressure drops to 0-5MPa within 15-30 minutes, the well is experiencing pump or tubing leakage. If the pressure drop is within 0.5MPa within 15-30 minutes, the well is not experiencing pump or tubing leakage, but rather a mismatch between the movement trajectory of the pump's fixed valve and the stroke and frequency of the pumping unit, causing the well to fail to produce fluid.

2. The method for determining the cause of pump inspection in oil wells and the method for remediation according to claim 1, characterized in that: The method for addressing the causes of oil well pump inspection and determining oil well remediation includes the following steps: For wells with pump or tubing leaks, perform pump inspection operations until the wells are restored to normal production; For oil wells where the problem is not pump leakage or tubing leakage, the following steps should be taken for well treatment: S201. Lower the sucker rod and polished rod retrieved in step S103 into the oil well and adjust the anti-surge distance. S202. Analyze the changes in daily fluid production in the 20-30 days before the well stops producing fluid; if the well production decreases by 10%-20%, adjust the well stroke frequency; if the well production decreases by 20%-40%, adjust the well stroke frequency or stroke length.

3. The method for determining the cause of pump inspection in oil wells and the method for remediation according to claim 2, characterized in that: If the oil well production decreases by 10%-20%, the pumping frequency of the oil well should be adjusted from the normal production frequency to 1.5 times. Start pumping the oil well for 2-3 hours. If the oil well dynamometer card shows normal operation, continue production for 24-48 hours. If the dynamometer card is still normal, adjust the pumping frequency back to the normal production frequency before the oil well stops producing fluid. If the oil well dynamometer card still reflects pump leakage or tubing leakage, then pump inspection should be performed.

4. The method for determining the cause of pump inspection in oil wells and the method for remediation according to claim 2, characterized in that: If the oil well production decreases by 20%-40%, the pumping frequency of the oil well should be adjusted from the normal production frequency to 1.5 times. After starting the pumping well for 2-3 hours, if the dynamometer card shows normal operation, continue production for 24-48 hours and if the dynamometer card remains normal, adjust the pumping frequency back to the normal production frequency before the oil well stops producing fluid. If the dynamometer card still reflects pump or tubing leakage, then pump inspection should be performed.

5. The method for determining the cause of pump inspection in oil wells and the method for remediation according to claim 2, characterized in that: If the oil well production decreases by 20%-40%, the well stroke rate is adjusted from the normal production stroke rate to 1.5 strokes. The well is started pumping for 2-3 hours. If the well dynamometer card shows insufficient fluid supply, the well stroke rate is reduced by one level and the well continues to produce. If the well dynamometer card still reflects pump leakage or tubing leakage, pump inspection is performed.