Shaft treatment potential coefficient determination method

Abstract

The invention relates to the technical field of oil production engineering, in particular to a shaft treatment potential coefficient determination method which comprises the steps that the number of wells corresponding to each pump inspection problem of each type of wells in a work area and the target pump inspection period and the actual pump inspection period of each type of wells are obtained; according to the number of the wells corresponding to each pump inspection problem of each type of wells, the proportion of the number of the wells corresponding to each pump inspection problem in the type of wells where the wells are located is determined, and the proportion is the proportion of the first pump inspection reason; and determining a first potential coefficient corresponding to each pump inspection problem of each type of wells according to the first pump inspection reason proportion and the target pump inspection period and the actual pump inspection period of each type of wells, and treating the work area shaft according to the first potential coefficient. The problems that in the prior art, when a treatment sequence is selected through human experience analysis, the treatment opportunity of the most urgent pump inspection problem is possibly delayed, and therefore a shaft is greatly damaged, and the production maintenance and labor cost is increased are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production engineering, and in particular to a method for determining a wellbore management potential coefficient. Background Art

[0002] Wellbore management is a long-term and complex project. Machine-drilled wells are large in size, with diverse lifting and displacement methods, and multiple nodes are involved in the management. During maintenance operations on machine-drilled wells, it was found that the location and form of downhole tool damage were complex and diverse. In the past, when managing wells, the priority of management was selected based on personal experience. Human-level personalized analysis could not provide guidance for the management of the next problem, and there was a possibility of delaying the timing of managing the most important and urgent detected problems. Given the long management cycle and limited production costs, there is an urgent need for a systematic method that can scientifically guide the thinking behind wellbore management. Summary of the Invention

[0003] The present invention proposes a method for determining the potential coefficient of wellbore treatment to solve the problem that in the past, when performing wellbore treatment, the treatment sequence was selected through human experience analysis, which may delay the treatment of the most urgent pump inspection problem, thereby causing greater damage to the wellbore and leading to increased production maintenance and labor costs.

[0004] According to one aspect of the present invention, a method for determining a wellbore remediation potential coefficient is provided, comprising:

[0005] Obtain the number of wells corresponding to each pump inspection problem for each type of well in the work area, as well as the target pump inspection cycle and actual pump inspection cycle for each type of well;

[0006] According to the number of wells corresponding to each pump inspection problem of each type of well, respectively determine the proportion of the number of wells corresponding to each pump inspection problem in the type of wells to which it belongs, and the proportion is the proportion of the first pump inspection reason;

[0007] According to the proportion of the first pump inspection reasons, the target pump inspection cycle and the actual pump inspection cycle of each type of well, the first potential coefficient corresponding to each pump inspection problem of each type of well is determined, and the wellbore in the work area is treated according to the first potential coefficient.

[0008] Preferably, each type of well includes at least: a pumping well, a screw pump well, and an electric pump well;

[0009] And / or, each pump inspection problem for each type of well is:

[0010] The pump inspection problems of the pumping well at least include: eccentric wear inspection, disconnection inspection, stuck pump inspection and leakage inspection;

[0011] The pump inspection problems of the screw pump well at least include: pump inspection for eccentric wear, pump inspection for stuck pump, pump inspection for disconnection and pump inspection for leakage;

[0012] The pump inspection problems of the electric pump well include at least: unreasonable operation, low insulation burning of the pump and failure of the protector.

[0013] Preferably, before obtaining the target pump inspection period for each type of well, the target pump inspection period for each type of well is determined, and the method includes:

[0014] Using the multivariate linear regression method, a quantitative relationship expression is established between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter, and pump diameter. Based on the quantitative relationship expression, the first pump inspection cycle is determined;

[0015] Using the cumulative distribution function and probability density distribution function of the three-parameter Weibull distribution, a reliability function of the target oil well under any time condition is established, and based on the reliability function, a second pump inspection period is determined;

[0016] Establishing an oil well failure risk assessment prediction model, determining a relationship curve between the risk coefficient and the number of operating days based on the prediction model, and determining a third pump inspection cycle based on the relationship curve;

[0017] Establishing simulation models of a sucker rod string, a tubing string, a rod-and-tube combination structure, a floating valve cover of a sucker pump, and a lost oil pump respectively, performing a minimum fatigue life simulation on the sucker rod string, the tubing string, the rod-and-tube combination structure, and the floating valve cover of the sucker pump, determining the corresponding fourth pump inspection cycle based on the minimum fatigue life, and establishing a relationship curve between displacement and wear times based on the simulation model of the lost oil pump, and determining the corresponding fourth pump inspection cycle based on the relationship curve;

[0018] Determine the average of the first pump inspection cycle, the second pump inspection cycle, the third pump inspection cycle, and the fourth pump inspection cycle as the target pump inspection cycle for the pumping well and the screw pump well;

[0019] The target pump inspection period of the electric pump well=average value+a, wherein the value range of a is 300-500.

[0020] Preferably, the established quantitative relationship expression between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter and pump diameter is:

[0021]

[0022] Where: T is the first pump inspection cycle, is a constant, They are stroke s, stroke number n, daily liquid output Q, water content f, and rod diameter d. r and pump diameter d p The corresponding coefficient.

[0023] Preferably, the reliability function is:

[0024]

[0025] Where: T is the standard number of days for the pump inspection cycle, d; m is the shape parameter, m>0; γ is the location parameter, γ≥0, when γ=0, it degenerates to a two-parameter Weibull distribution; η is the scale parameter, η>0; t s is the starting date of the forecast period; t e The end date of the forecast period.

[0026]

[0027] Where: M is the total number of wells in the pump inspection operation sample, dimensionless; L is the number of oil wells that have undergone pump inspection operation at working time T, dimensionless, and T is the second pump inspection cycle.

[0028] Preferably, the established oil well failure risk assessment prediction model is:

[0029]

[0030] Where: T is the second pump inspection period, γ is the position parameter, m is the shape parameter, and η is the scale parameter.

[0031] Preferably, the method for determining the proportion of the number of wells corresponding to each pump inspection problem in the category of wells to which the well belongs includes:

[0032] The proportion of the first pump inspection reason = the number of wells corresponding to the pump inspection problem / the total number of pump inspection wells corresponding to the type of wells in which the pump inspection problem occurs;

[0033] And / or, the method for determining the first potential coefficient corresponding to each pump inspection problem of each type of well based on the first pump inspection reason proportion, the target pump inspection period and the actual pump inspection period of each type of well includes:

[0034]

[0035] Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection problem occurs.

[0036] Preferably, it also includes:

[0037] Obtain the number of wells corresponding to each pump inspection factor for each pump inspection problem of the pumping wells, and the number of wells corresponding to each pump inspection factor for eccentric wear inspection, stuck pump inspection, and disconnected pump inspection in the screw pump wells;

[0038] Determine the proportion of each pump inspection factor in the pump inspection problem according to the number of wells corresponding to the pump inspection factor, and the proportion is the proportion of the second pump inspection reason;

[0039] According to the proportion of the second pump inspection reasons, the target pump inspection cycle and the actual pump inspection cycle, the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well is determined, and the wellbore in the work area is treated according to the second potential coefficient.

[0040] Preferably, each pump inspection factor of each pump inspection problem of each type of well includes:

[0041] Among the pump inspection problems of the pumping well, the inspection factors of the eccentric wear inspection include at least: oil pipe leakage, rod breakage, pipe wear and rod wear; the inspection factors of the broken pump inspection include at least: rod breakage, disconnector breakage, pipe breakage and centralizer breakage; the inspection factors of the stuck pump inspection include at least: sand sticking, wax sticking, piston strain and scale sticking; the inspection factors of the leakage inspection include at least: piston valve cover breakage and fixed valve leakage;

[0042] Among the pump inspection problems of the screw pump well, the inspection factors of the eccentric wear inspection include at least: rod breakage and pipe leakage, the inspection factors of the stuck pump inspection include at least: wax sticking, sand sticking and scale sticking, and the inspection factors of the broken and detached pump inspection include at least: rod breakage, tubing detachment, rod detachment and rod buckling.

[0043] Preferably, the method for determining the proportion of each pump inspection factor in the pump inspection problem in which it is located includes:

[0044] The proportion of the second pump inspection reason = the number of wells corresponding to the pump inspection factor / the total number of pump inspection wells corresponding to the pump inspection problem of the pump inspection factor;

[0045] And / or, the method for determining the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well based on the second pump inspection reason proportion, the target pump inspection cycle, and the actual pump inspection cycle includes:

[0046]

[0047] Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection factor is located.

[0048] The present invention has at least the following beneficial effects:

[0049] The present invention proposes a method for determining the potential coefficient of wellbore treatment. By determining the potential coefficient corresponding to each pump inspection problem of each type of well, it is possible to fully analyze and evaluate the importance and urgency of the currently detected problems, thereby implementing targeted treatment measures, reducing the pump inspection rate of machine-drilled wells, and lowering production maintenance and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0051] Figure 1 A flow chart showing a method for determining a wellbore remediation potential coefficient according to an embodiment of the present invention;

[0052] Figure 2 A first potential coefficient chart corresponding to each pump inspection problem of a pumping well according to an embodiment of the present invention is shown;

[0053] Figure 3 A second potential coefficient chart corresponding to each pump inspection factor of each pump inspection problem of a pumping well according to an embodiment of the present invention is shown;

[0054] Figure 4 A first potential coefficient chart corresponding to each pump inspection problem of a screw pump well according to an embodiment of the present invention is shown;

[0055] Figure 5 A second potential coefficient chart corresponding to each pump inspection factor of each pump inspection problem of a screw pump well according to an embodiment of the present invention is shown;

[0056] Figure 6 A first potential coefficient chart corresponding to each pump inspection problem of an electric pump well according to an embodiment of the present invention is shown;

[0057] Figure 7 A curve showing the relationship between the risk coefficient of an oil well and the number of operating days according to an embodiment of the present invention is shown;

[0058] Figure 8 A curve showing the relationship between the oil well discharge rate and the number of wear times according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0059] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0060] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0061] The term "and / or" herein simply describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of three situations: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0062] In addition, numerous specific details are provided in the following detailed description to better illustrate the present invention. Those skilled in the art will appreciate that the present invention may be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of the present invention.

[0063] Figure 1 A flow chart showing a method for determining a wellbore remediation potential coefficient according to an embodiment of the present invention; Figure 2 A first potential coefficient chart corresponding to each pump inspection problem of a pumping well according to an embodiment of the present invention is shown; Figure 3 A second potential coefficient chart corresponding to each pump inspection factor of each pump inspection problem of a pumping well according to an embodiment of the present invention is shown; Figure 4 A first potential coefficient chart corresponding to each pump inspection problem of a screw pump well according to an embodiment of the present invention is shown; Figure 5 A second potential coefficient chart corresponding to each pump inspection factor of each pump inspection problem of a screw pump well according to an embodiment of the present invention is shown; Figure 6 A first potential coefficient chart corresponding to each pump inspection problem of an electric pump well according to an embodiment of the present invention is shown; Figure 7 A curve showing the relationship between the risk coefficient of an oil well and the number of operating days according to an embodiment of the present invention is shown; Figure 8 The relationship curve between the oil well discharge volume and the number of wear times according to the embodiment of the present invention is shown. Figure 1-8 As shown, a method for determining a potential coefficient of wellbore treatment includes: step S01: obtaining the number of wells corresponding to each pump inspection problem of each type of well in the work area, as well as the target pump inspection cycle and actual pump inspection cycle of each type of well; step S02: according to the number of wells corresponding to each pump inspection problem of each type of well, determining the proportion of the number of wells corresponding to each pump inspection problem in the type of wells in which it is located, and the proportion is the first pump inspection reason proportion; step S03: according to the first pump inspection reason proportion, the target pump inspection cycle and actual pump inspection cycle of each type of well, determining the first potential coefficient corresponding to each pump inspection problem of each type of well, and treating the wellbore in the work area according to the first potential coefficient.

[0064] A method for determining a wellbore remediation potential coefficient provided by an embodiment of the present invention specifically includes the following steps:

[0065] Step S01: Obtain the number of wells corresponding to each pump inspection problem for each type of well in the work area, as well as the target pump inspection cycle and actual pump inspection cycle for each type of well.

[0066] In the present invention, each type of well includes at least: oil pumping wells, screw pump wells and electric pump wells; and / or, each pump inspection problem of each type of well is: the pump inspection problems of the oil pumping wells include at least: eccentric wear pump inspection, disconnection pump inspection, stuck pump inspection and leakage pump inspection; the pump inspection problems of the screw pump wells include at least: eccentric wear pump inspection, stuck pump inspection, disconnection pump inspection and leakage pump inspection; the pump inspection problems of the electric pump wells include at least: unreasonable operation, low insulation burning pump and protector failure.

[0067] In an embodiment of the present invention, by analyzing the pump inspection conditions of the three most commonly used wells in oil fields, namely, pumping wells, screw pump wells and electric pump wells, it is found that the pump inspection problems of pumping wells and screw pump wells mainly include four problems: eccentric wear, disconnection, pump sticking, and leakage. The problems of electric pump wells include three problems: unreasonable operation, low insulation burning of the pump, and protector failure. The order of treating each pump inspection problem is particularly critical. Targeted treatment should be given priority to the most important and urgent detection problems to prevent major production accidents or greater losses due to delays.

[0068] In the present invention, before obtaining the target pump inspection cycle for each type of well, the target pump inspection cycle for each type of well is determined, and the method includes: using the multivariate linear regression method to establish a quantitative relationship expression between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter and pump diameter, and determining the first pump inspection cycle based on the quantitative relationship expression; using the cumulative distribution function and probability density distribution function of the three-parameter Weibull distribution to establish a reliability function of the target oil well under any time condition, and determining the second pump inspection cycle based on the reliability function; establishing an oil well failure risk assessment prediction model, determining a relationship curve between the risk coefficient and the number of operating days based on the prediction model, and determining the third pump inspection cycle based on the relationship curve; respectively establishing A simulation model of a sucker rod string, a tubing string, a rod-and-pipe combination structure, a floating valve cover of a pump, and leakage of a pump is established, and a minimum fatigue life simulation is performed on the sucker rod string, the tubing string, the rod-and-pipe combination structure, and the floating valve cover of the pump. Based on the minimum fatigue life, the corresponding fourth pump inspection cycle is determined. Based on the simulation model of leakage of the pump, a relationship curve between displacement and wear times is established, and based on the relationship curve, the corresponding fourth pump inspection cycle is determined; the average value of the first pump inspection cycle, the second pump inspection cycle, the third pump inspection cycle, and the fourth pump inspection cycle is determined as the target pump inspection cycle for the pumping well and the screw pump well; the target pump inspection cycle of the electric pump well = average value + a, where a ranges from 300 to 500.

[0069] In an embodiment of the present invention, the target pump inspection cycle of the target oil well in the work area can be predicted by a variety of methods. The present invention adopts four methods to determine the pump inspection cycle. The first method to determine the pump inspection cycle is to use multiple linear regression to predict the pump inspection cycle. Since the pump inspection cycle is affected by multiple factors, the regression analysis method can be used to study the main factors that can be controlled artificially, and establish an empirical expression of the quantitative relationship between the oil well pump inspection cycle and its influencing factors. Multiple linear regression uses multiple factors that affect the pump inspection cycle as independent variables, such as pump diameter, rod diameter, stroke, stroke frequency, water content, daily liquid production, etc., and the pump inspection cycle as the dependent variable to establish a quantitative relationship expression between the independent variable and the multiple dependent variables, that is, a regression equation.

[0070] In the present invention, the quantitative relationship between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter and pump diameter is expressed as follows:

[0071]

[0072] Where: T is the first pump inspection cycle, is a constant, They are stroke s, stroke number n, daily liquid output Q, water content f, and rod diameter d. r and pump diameter d p The corresponding coefficient.

[0073] In the embodiment of the present invention, the values ​​of the various parameter coefficients in formula (1) are obtained by obtaining previous data and performing multiple linear regression. The specific values ​​of the parameter coefficients are shown in Table 1 below.

[0074] Table 1: Multiple linear regression coefficient value table for pump inspection cycle

[0075] factor constant stroke rush Daily liquid production Moisture content Rod diameter Pump diameter coefficient 265.182 -211.68 93.65 9.596 -2.952 39.152 25.129

[0076] Therefore, the quantitative relationship expression between the pump inspection cycle and the stroke, stroke frequency, daily liquid production, water content, rod diameter, and pump diameter is obtained, namely:

[0077]

[0078] By substituting the various parameter values ​​of the target well into the above formula (1-1), it is obtained that the first pump inspection cycle of the target well is 893 days.

[0079] The second method for determining pump inspection cycles is to use the three-parameter Weibull distribution to predict pump inspection cycles. During oil well operation, downhole equipment failures are somewhat random. While the time a piece of equipment can remain operational before a failure can vary significantly, the operating life of the same type of equipment under similar conditions generally follows certain statistical patterns. The theory of macroscopically predicting equipment life and oil well pump inspection cycles using statistical analysis and probability distribution models is known as reliability theory. Through statistical analysis of pump inspection cycles in pumping wells, the three-parameter Weibull distribution was chosen to establish a probability density distribution model for the pump inspection cycle.

[0080] The cumulative distribution function of the three-parameter Weibull distribution of the pump inspection period is:

[0081]

[0082] The probability density function of the Weibull distribution of the pump inspection period obtained according to (2-2) is:

[0083]

[0084] Where: m is the shape parameter, m>0; γ is the location parameter, γ≥0, when γ=0, it degenerates into a two-parameter Weibull distribution; η is the scale parameter, η>0; T is the standard number of days of the pump inspection cycle, d.

[0085] Here, the ratio of the number of wells that have undergone pump inspections to the total number of operational wells at a pump inspection time T is defined as the equipment reliability corresponding to that operational lifespan. Based on the established pump inspection cycle probability density function, a reliability function can be constructed for oil wells operating for any desired time (i.e., pump inspection cycle length) T.

[0086] In the present invention, the reliability function is:

[0087]

[0088] Where: T is the standard number of days for the pump inspection cycle, d; m is the shape parameter, m>0; γ is the location parameter, γ≥0, when γ=0, it degenerates to a two-parameter Weibull distribution; η is the scale parameter, η>0; t s is the starting date of the forecast period; t e is the end date of the forecast period, and d is the differential symbol.

[0089]

[0090] Where: M is the total number of wells in the pump inspection operation sample, dimensionless; L is the number of oil wells that have undergone pump inspection operation at working time T, dimensionless, and T is the second pump inspection cycle.

[0091] According to the reliability function of formula (2) and (2-1), the second pump inspection period T is calculated to be 933 days.

[0092] A third method for determining pump inspection cycles is to predict them by establishing an oil well failure risk assessment model. Oil well failure risk refers to the probability that a well will fail or require pump inspection during normal operation. The oil well failure rate is the proportion of wells that have not yet undergone pump inspection at a certain point in time, representing the probability of failure of any single well per unit time after that point. A predictive model for oil well failure risk assessment is developed based on the three parameters of the Weibull distribution.

[0093] In the present invention, the established oil well failure risk assessment prediction model is:

[0094]

[0095] Where: T is the second pump inspection period, γ is the position parameter, m is the shape parameter, and η is the scale parameter.

[0096] Using risk assessment models, we can conduct risk assessments on individual wells and all wells in a block. We can also classify oil well failure risk factors based on the probability of failure, establish a risk early warning mechanism, and guide planned pump inspections on oil wells.

[0097] Using the above prediction model, the risk coefficient of failure of any oil well at a certain time can be predicted. Taking 437 pump inspection operations of 119 pump inspection wells in a certain work area as statistical samples, a regression analysis is performed on the parameter values ​​of the Weibull distribution of the pump inspection cycle. The regression calculation results are: shape parameter m = 0.7719, scale parameter η = 711.21, and position parameter γ = 0.3296. Based on the three parameter values ​​obtained by the above regression analysis, the relationship between the single well risk coefficient of the target oil well and the number of operating days is calculated using formula (3), and a relationship curve is drawn. The results are shown as follows: Figure 7 The inflection point of the relationship curve, or the number of operating days corresponding to the predetermined risk coefficient value, is the predicted third pump inspection cycle. The predetermined risk coefficient is 0.9, meaning that when the failure risk is greater than 0.9, the system is identified as being in the high-risk failure zone.

[0098] Depend on Figure 7 The results show that after the well undergoes a pump inspection and is put into production, its failure risk factor gradually increases with the number of operating days, then gradually approaches 1. For the target oil well, at 1400 days of production (the third pump inspection cycle), the risk factor is 0.9 (the predetermined risk factor), which puts it in the high-risk failure zone, emphasizing the need to be vigilant about the risk of well failure.

[0099] The fourth method to determine the pump inspection cycle is to simulate the service life of the sucker rod string, tubing string, rod-tubing combination structure and the sucker pump. The most commonly used sucker rods have nominal diameters of 22mm and 25mm respectively. This embodiment takes 25mm as an example, establishes a simulation model of the sucker rod string in the ANSYS Workbench environment, and simulates the fatigue of the sucker rod under actual alternating loads. The simulation results show that the most prone location for fatigue damage in the sucker rod is the middle of the sucker rod body, and the minimum fatigue life of the sucker rod string is 5.78*10 6 times, according to the 4min rush -1 Calculate the safe working time of the uppermost sucker rod, where the calculation formula for the fourth pump inspection cycle is:

[0100] The fourth pump inspection cycle T = minimum fatigue life / (strokes per minute * 60 minutes * 24 hours) (4);

[0101] Therefore, the fourth pump check cycle of the sucker rod = 5.78*10 6 / (4*60*24)=1004 days.

[0102] A simulation model of the tubing string was established in ANSYS. The most commonly used tubing specifications are 2-7 / 8” and 3-1 / 2”. The fatigue condition of the tubing under actual alternating loads was simulated, and the minimum fatigue life of the tubing string was found to be 7.63*10 6 times, according to the stroke 4min -1 Calculate and substitute into formula (4) to obtain the safe working time of the tubing string, that is, the fourth pump inspection cycle of the tubing string is 1325 days.

[0103] The presence of eccentric wear between the rod and the tubing (rod and tubing combination structure) will further increase the rate of tool damage. Since the installation density of downhole sucker rod centralizers is usually 5-10m, the minimum bending radius of the sucker rod section between the two centralizers is 3.96m, and the deflection y at the midpoint of the rod section is 1. max =41.95mm, a simulation model of the rod-tube assembly was established, and the dynamic simulation of the rod-tube assembly structure was performed using the simulation model to analyze its fatigue life. Based on the minimum fatigue life of the sucker rod and tubing string at the rod-tube assembly structure obtained by simulation, the equivalent life of the sucker rod at the rod-tube assembly structure was calculated by substituting them into formula (4), i.e., the fourth pump inspection cycle of the sucker rod at the rod-tube assembly structure was 895.4 days. The equivalent working days of the tubing body were calculated, i.e., the fourth pump inspection cycle of the tubing at the rod-tube assembly structure was 1019 days.

[0104] The most widely used oil well pumps are tubular pumps with diameters of ф57, ф70, ф83, and ф95. This embodiment uses a ф57 pump as an example to establish an oil well pump simulation model. The simulation model is used to simulate and analyze the fatigue life of the floating valve cover and oil well pump leakage of the oil well pump. Based on the obtained life distribution of the oil well pump valve body, the fatigue life at the upper edge of its oil outlet groove, that is, the fourth pump inspection cycle of the floating valve cover oil outlet groove, is calculated using formula (4) to be 954 days, while the fatigue life at the root of the upper thread, that is, the fourth pump inspection cycle of the floating valve cover thread, is 1009 days. The pump inspection cycles at the two locations are relatively close in value. Considering the close distance between the two locations, the fracture failures in the two cases can be regarded as the same failure location, and the smaller value is taken, that is, the fourth pump inspection cycle of the floating valve cover of the oil well pump is 954 days.

[0105] As the reciprocating motion progresses, the outer surface of the plunger and the inner surface of the bushing continuously rub against each other, causing the annular gap between the plunger and the pump barrel to continue to expand, causing the leakage of the oil pump to intensify. Similar to the leakage phenomenon of the oil pipe, when the leakage flow exceeds the acceptable range of economic production, the pump must be inspected. Through the established oil pump simulation model, the oil pump leakage is simulated, the leakage change is observed, and the relationship table between the number of reciprocating wear and displacement is established. The results are as follows: Figure 8 According to the relationship table, the number of wear times corresponding to when the actual liquid production (displacement) is lower than the predetermined percentage of the ideal displacement is determined. The number of operating days corresponding to this number of wear times is the fourth pump inspection cycle corresponding to the oil well pump leakage. The predetermined percentage is 80%.

[0106] Figure 8 Shown in experienced wear 5.37*10 6 After the leakage of the annular fluid is 0.015m 3 / s, equivalent to a mass flow rate of 1.12t / d; the actual liquid flow rate lifted to the wellhead is 0.182m 3 / s, which is equivalent to a mass flow rate of 14.28t / d and a loss ratio of 7.27%. The actual production of the oil well is 80% lower than the ideal displacement, and the lifting efficiency of the oil well no longer meets the production requirements. At this time, the wear times are 5.37*10 6 The number of days corresponding to the fourth pump inspection cycle corresponding to the oil pump leakage is 933 days.

[0107] The first pump inspection cycle, the second pump inspection cycle, the third pump inspection cycle and the fourth pump inspection cycle corresponding to the sucker rod string, the tubing string, the rod-tubing combination structure, the floating valve cover of the sucker pump and the sucker pump leakage obtained according to the above process are summed and the average value is taken. The specific results are shown in Table 2 below.

[0108] Table 2: Statistics of pump inspection cycles for target wells

[0109]

[0110]

[0111] Pumping wells and screw pump wells are both lifted by rod pumps, so the target pump inspection cycle for these two types of wells is. Since electric pump wells are lifted by rodless pumps and are not affected by eccentric wear, the target pump inspection cycle should be 300 to 500 days longer than that of pumping wells.

[0112] Step S02: According to the number of wells corresponding to each pump inspection problem of each type of well, respectively determine the proportion of the number of wells corresponding to each pump inspection problem in the type of wells to which it belongs, and the proportion is the proportion of the first pump inspection reason.

[0113] Step S03: Determine a first potential coefficient corresponding to each pump inspection problem of each type of well based on the first pump inspection reason ratio, the target pump inspection cycle and the actual pump inspection cycle of each type of well, and treat the wellbore in the work area based on the first potential coefficient.

[0114] In the present invention, the method for determining the proportion of the number of wells corresponding to each pump inspection problem in the category of wells to which the well belongs includes:

[0115] The proportion of the first pump inspection reason = the number of wells corresponding to the pump inspection problem / the total number of pump inspection wells corresponding to the type of wells in which the pump inspection problem occurs (5);

[0116] And / or, the method for determining the first potential coefficient corresponding to each pump inspection problem of each type of well based on the first pump inspection reason proportion, the target pump inspection period and the actual pump inspection period of each type of well includes:

[0117]

[0118] Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection problem occurs.

[0119] In an embodiment of the present invention, the first potential coefficient calculation formula includes two calculation factors: the influence of the proportion of pump inspection reasons and the influence of the pump inspection cycle. The larger the sum of the two factors, the larger the potential coefficient, which proves that the more prominent the detection problem is, the more efforts should be made to control it. Conversely, the smaller the potential coefficient, the fewer the detection problems occur and the longer the pump inspection cycle.

[0120] Taking the pumping wells in a certain work area as an example, the number of wells that have four types of pump inspection problems, namely, eccentric wear pump inspection, disconnection pump inspection, stuck pump inspection, and leakage pump inspection, is obtained during the predetermined period. The well type corresponding to the pump inspection problem is also obtained, that is, the total number of pump inspection wells of the pumping wells. Substituting it into formula (5) is calculated to obtain the proportion of the first pump inspection reason corresponding to the pumping wells.

[0121] Obtain the actual pump inspection cycle of the pumping wells in the work area, substitute the first pump inspection reason ratio, actual pump inspection cycle, and target pump inspection cycle (1039.6≈1000d) of the pumping wells obtained according to the above process into formula (6), and calculate the first potential coefficient corresponding to each pump inspection problem of the pumping wells. The results are as follows: Figure 2 As shown, in Figure 2 In the figure, a is the proportion of the first pump inspection reason, b is That is, the cycle coefficient, c is the distance coefficient from the target pump inspection cycle (the number of days between the actual pump inspection cycle and the target pump inspection cycle), which is calculated by Figure 2 It can be seen that the first potential coefficients of various pump inspection problems of the pumping wells are ranked from high to low as wear, breakage, sticking, and leakage. Therefore, when treating the wellbore of the pumping wells in the work area, the treatment should be carried out in the order of the pump inspection problems.

[0122] The number of screw pump wells that have four types of pump inspection problems, namely, eccentric wear, disconnection, stuck pumps, and leakage, is obtained during the predetermined period of time. The well types corresponding to the pump inspection problems are also obtained, namely, the total number of screw pump inspection wells. Substitute them into formula (5) to calculate the proportion of the first pump inspection reason corresponding to the screw pump wells.

[0123] Obtain the actual pump inspection cycle of the screw pump wells in the work area, substitute the first pump inspection reason proportion, actual pump inspection cycle, and the target pump inspection cycle (1000d) of the screw pump wells obtained according to the above process into formula (6), and calculate the first potential coefficient corresponding to each pump inspection problem of the screw pump wells. The results are as follows: Figure 4 As shown by Figure 4 It can be seen that the first potential coefficients of various pump inspection problems of screw pump wells are ranked from high to low as wear, sticking, breaking and leakage. Therefore, when treating the wellbore of the screw pump well in the work area, the treatment should be carried out in the order of the pump inspection problems.

[0124] The number of wells with three types of pump inspection problems, namely, unreasonable operation, low insulation burning pump, and protector failure, in the work area electric pump wells during the predetermined period is obtained respectively, and the well type corresponding to the pump inspection problem is obtained, that is, the total number of pump inspection wells of the electric pump wells. Substitute it into formula (5) to calculate the proportion of the first pump inspection reason corresponding to the electric pump wells.

[0125] Obtain the actual pump inspection cycle of the electric pump wells in the work area, substitute the first pump inspection reason ratio, actual pump inspection cycle, and the target pump inspection cycle (1500d) of the electric pump wells obtained according to the above process into formula (6), and calculate the first potential coefficient corresponding to each pump inspection problem of the electric pump wells. The results are as follows: Figure 6 As shown by Figure 6It can be seen that the first potential coefficients of various pump inspection problems of the electric pump well are ranked from high to low as unreasonable operation, low insulation pump burning and protector failure. Therefore, when conducting the treatment of the electric pump well in the work area, the treatment should be carried out in the order of the pump inspection problems.

[0126] The present invention also includes: obtaining the number of wells corresponding to each pump inspection factor of each pump inspection problem of the pumping wells and the number of wells corresponding to each pump inspection factor of the eccentric wear pump inspection, stuck pump inspection and disconnected pump inspection of the screw pump wells; according to the number of wells corresponding to the pump inspection factors, determining the proportion of each pump inspection factor in the pump inspection problem in which it is located, and the proportion is the second pump inspection cause proportion; according to the second pump inspection cause proportion, the target pump inspection cycle and the actual pump inspection cycle, determining the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well, and treating the wellbore in the work area according to the second potential coefficient.

[0127] In the present invention, each pump inspection factor of each pump inspection problem of each type of well includes: among the pump inspection problems of the pumping wells, the pump inspection factors of the eccentric wear pump inspection include at least: oil pipe leakage, rod breakage, pipe wear and rod wear, the pump inspection factors of the broken pump inspection include at least: rod breakage, connector breakage, pipe breakage and stabilizer breakage, the pump inspection factors of the stuck pump inspection include at least: sand sticking, wax sticking (wax leakage), piston strain and scale sticking, the pump inspection factors of the leakage pump inspection include at least: piston valve cover breakage and fixed valve leakage; among the pump inspection problems of the screw pump wells, the pump inspection factors of the eccentric wear pump inspection include at least: rod breakage and pipe leakage, the pump inspection factors of the stuck pump inspection include at least: wax sticking, sand sticking and scale sticking, the pump inspection factors of the broken pump inspection include at least: rod breakage, oil pipe loss, rod loss and rod buckling.

[0128] In the present invention, the method for determining the proportion of each pump inspection factor in the pump inspection problem in which it is located includes:

[0129] The proportion of the second pump inspection reason = the number of wells corresponding to the pump inspection factor / the total number of pump inspection wells corresponding to the pump inspection problem where the pump inspection factor is located (7);

[0130] And / or, the method for determining the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well based on the second pump inspection reason proportion, the target pump inspection cycle, and the actual pump inspection cycle includes:

[0131]

[0132] Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection factor is located.

[0133] In an embodiment of the present invention, after determining the priority order for treating various pump inspection problems for each type of well, each pump inspection problem also includes multiple specific pump inspection factors. After determining the pump inspection problem to be treated first, the priority order for treating the pump inspection factors included in each pump inspection problem, that is, the second potential coefficient, can also be determined.

[0134] Taking the eccentric wear pump inspection problem of the pumping wells in a certain work area as an example, the number of wells corresponding to the four pump inspection factors, namely, tubing leakage, rod wear, pipe wear and rod wear, is obtained within a predetermined period, and the pump inspection problems corresponding to these pump inspection factors, namely, the total number of pump inspection wells with eccentric wear pump inspection, are obtained. Substituting them into formula (7), the proportion of the second pump inspection reason corresponding to each pump inspection factor of the eccentric wear pump inspection problem is calculated.

[0135] Substitute the second pump inspection reason proportion corresponding to each pump inspection factor of the above-mentioned pumping well eccentric wear pump inspection problem, the actual pump inspection cycle of the pumping well, and the target pump inspection cycle (1000d) of the pumping well obtained according to the above process into formula (8), and calculate the second potential coefficient corresponding to each pump inspection factor of the pumping well eccentric wear pump inspection problem. The results are as follows: Figure 3 As shown in Figure a, Figure 3 As can be seen from Figure a, the second potential coefficients of the eccentric wear problem of the pumping wells are ranked from high to low as oil pipe leakage, rod breakage, pipe wear and rod wear. Therefore, when treating the eccentric wear and pump inspection problem of the pumping wells in the work area, the treatment should be carried out in the order of the pump inspection factors. Similarly, the second potential coefficient corresponding to each pump inspection factor of the pumping well breakage and pump inspection problem is determined, and the results are as follows. Figure 3 As shown in Figure b, the order of pump inspection factors is: rod breakage, disconnector breakage, pipe breakage, and stabilizer breakage; determine the second potential coefficient corresponding to each pump inspection factor of the pumping well stuck pump inspection problem, and the result is as follows Figure 3 As shown in Figure c, the order of pump inspection factors is: sand sticking, wax sticking, piston strain and scale sticking; determine the second potential coefficient corresponding to each pump inspection factor of the pumping well leakage inspection problem, the result is as follows Figure 3 As shown in Figure d, the order of pump inspection factors is: piston valve cover breakage and fixed valve leakage.

[0136] According to the above process, the second potential coefficient corresponding to the pump inspection factor of the eccentric wear pump in the pump inspection problem of the screw pump well is determined. The results are as follows: Figure 5 As shown in Figure A, the order of pump inspection factors is: rod wear and tear, pipe wear and leakage; determine the second potential coefficient corresponding to the pump inspection factor of the screw pump well in the pump inspection problem, the result is as follows Figure 5 As shown in Figure B, the order of pump inspection factors is: wax sticking, sand sticking and scale sticking; the second potential coefficient corresponding to the pump inspection factor of the screw pump well is determined. The results are as follows Figure 5As shown in Figure C, the order of pump inspection factors is: rod breakage, oil pipe detachment, rod detachment and rod buckling.

[0137] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, the present invention will not elaborate on them.

[0138] Those skilled in the art will understand that in the above-mentioned method of the specific implementation method, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0139] In view of the current situation that the wellbore management cycle is long, the pump inspection rate of machine-generated wells is increasing, the pump inspection cycle is shortened, and the maintenance operation cost is rising, the present invention proposes a method that can scientifically guide wellbore management. By introducing the concept of "potential coefficient", the three factors of the proportion of pump inspection reasons, the target pump inspection cycle, and the actual pump inspection cycle are studied, and a set of methods that can effectively evaluate the urgency of the management of pump inspection problems is developed. It can fully evaluate the "importance and urgency" of the currently detected problems, so as to implement targeted management measures and reduce the pump inspection rate of machine-generated wells.

[0140] The method of the present invention was applied to a certain work area of ​​an oil field to implement targeted treatment technical measures. Targeted treatment measures were carried out for the four main influencing factors of "eccentric wear, breakage, pump sticking, and leakage" in more than 6,000 wells. The results showed that the pump inspection rate of machine-drilled wells decreased by 5.9 percentage points, the pump inspection cycle was extended by 22 days, 226 wells were inspected less, and the pump inspection cost was saved by more than 30 million yuan. It is expected to generate economic benefits of 29.84 million yuan.

[0141] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for determining a wellbore remediation potential coefficient, characterized in that: include: Obtain the number of wells corresponding to each pump inspection problem for each type of well in the work area, as well as the target pump inspection cycle and actual pump inspection cycle for each type of well; According to the number of wells corresponding to each pump inspection problem of each type of well, respectively determine the proportion of the number of wells corresponding to each pump inspection problem in the type of wells to which it belongs, and the proportion is the proportion of the first pump inspection reason; According to the proportion of the first pump inspection reasons, the target pump inspection cycle and the actual pump inspection cycle of each type of well, the first potential coefficient corresponding to each pump inspection problem of each type of well is determined, and the wellbore in the work area is treated according to the first potential coefficient.

2. The method for determining the wellbore treatment potential coefficient according to claim 1, characterized in that: Each type of well at least includes: a pumping well, a screw pump well, and an electric pump well; And / or, each pump inspection problem for each type of well is: The pump inspection problems of the pumping well at least include: eccentric wear inspection, disconnection inspection, stuck pump inspection and leakage inspection; The pump inspection problems of the screw pump well at least include: eccentric wear inspection, stuck pump inspection, disconnection inspection and leakage inspection; The pump inspection problems of the electric pump well include at least: unreasonable operation, low insulation burning of the pump and failure of the protector.

3. The method for determining the wellbore treatment potential coefficient according to claim 2, characterized in that: Before obtaining the target pump inspection period for each type of well, the target pump inspection period for each type of well is determined, and the method includes: Using the multivariate linear regression method, a quantitative relationship expression is established between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter, and pump diameter. Based on the quantitative relationship expression, the first pump inspection cycle is determined; Using the cumulative distribution function and probability density distribution function of the three-parameter Weibull distribution, a reliability function of the target oil well under any time condition is established, and based on the reliability function, a second pump inspection period is determined; Establishing an oil well failure risk assessment prediction model, determining a relationship curve between the risk coefficient and the number of operating days based on the prediction model, and determining a third pump inspection cycle based on the relationship curve; Establishing simulation models of a sucker rod string, a tubing string, a rod-and-tube combination structure, a floating valve cover of a sucker pump, and a lost oil pump respectively, performing a minimum fatigue life simulation on the sucker rod string, the tubing string, the rod-and-tube combination structure, and the floating valve cover of the sucker pump, determining the corresponding fourth pump inspection cycle based on the minimum fatigue life, and establishing a relationship curve between displacement and wear times based on the simulation model of the lost oil pump, and determining the corresponding fourth pump inspection cycle based on the relationship curve; Determine the average of the first pump inspection cycle, the second pump inspection cycle, the third pump inspection cycle, and the fourth pump inspection cycle as the target pump inspection cycle for the pumping well and the screw pump well; The target pump inspection period of the electric pump well=average value+a, wherein the value range of a is 300-500.

4. The method for determining the wellbore treatment potential coefficient according to claim 3, characterized in that: The quantitative relationship expression between the pump inspection cycle and the stroke, number of strokes, daily liquid production, water content, rod diameter and pump diameter is as follows: Where: T is the first pump inspection cycle, is a constant, They are stroke s, stroke number n, daily liquid output Q, water content f, and rod diameter d. r and pump diameter d p The corresponding coefficient.

5. The method for determining the wellbore treatment potential coefficient according to claim 3, characterized in that: The reliability function is: Where: T is the standard number of days for the pump inspection cycle, d; m is the shape parameter, m>0; γ is the location parameter, γ≥0, when γ=0, it degenerates to a two-parameter Weibull distribution; η is the scale parameter, η>0; t s is the starting date of the forecast period; t e is the end date of the forecast period; Where: M is the total number of wells in the pump inspection operation sample, dimensionless; L is the number of oil wells that have undergone pump inspection operation at working time T, dimensionless, and T is the second pump inspection cycle.

6. The method for determining the wellbore treatment potential coefficient according to claim 3, characterized in that: The established oil well failure risk assessment prediction model is: Where: T is the second pump inspection period, γ is the position parameter, m is the shape parameter, and η is the scale parameter.

7. The method for determining the wellbore remediation potential coefficient according to claim 1, characterized in that: The method for determining the proportion of the number of wells corresponding to each pump inspection problem in the category of wells to which the well belongs includes: The proportion of the first pump inspection reason = the number of wells corresponding to the pump inspection problem / the total number of pump inspection wells corresponding to the type of wells in which the pump inspection problem occurs; And / or, the method for determining the first potential coefficient corresponding to each pump inspection problem of each type of well based on the first pump inspection reason proportion, the target pump inspection period and the actual pump inspection period of each type of well includes: Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection problem occurs.

8. The method for determining the wellbore treatment potential coefficient according to any one of claims 2 to 7, characterized in that: Also includes: Obtain the number of wells corresponding to each pump inspection factor for each pump inspection problem of the pumping wells, and the number of wells corresponding to each pump inspection factor for the eccentric wear inspection, stuck pump inspection, and disconnected pump inspection of the screw pump wells; Determine the proportion of each pump inspection factor in the pump inspection problem according to the number of wells corresponding to the pump inspection factor, and the proportion is the proportion of the second pump inspection reason; According to the proportion of the second pump inspection reasons, the target pump inspection cycle and the actual pump inspection cycle, the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well is determined, and the wellbore in the work area is treated according to the second potential coefficient.

9. The method for determining the wellbore treatment potential coefficient according to claim 8, characterized in that: Each pump inspection factor for each pump inspection problem in each type of well includes: Among the pump inspection problems of the pumping well, the inspection factors of the eccentric wear inspection include at least: oil pipe leakage, rod breakage, pipe wear and rod wear; the inspection factors of the broken pump inspection include at least: rod breakage, disconnector breakage, pipe breakage and centralizer breakage; the inspection factors of the stuck pump inspection include at least: sand sticking, wax sticking, piston strain and scale sticking; the inspection factors of the leakage inspection include at least: piston valve cover breakage and fixed valve leakage; Among the pump inspection problems of the screw pump well, the inspection factors of the eccentric wear inspection include at least: rod breakage and pipe leakage, the inspection factors of the stuck pump inspection include at least: wax sticking, sand sticking and scale sticking, and the inspection factors of the broken and detached pump inspection include at least: rod breakage, tubing detachment, rod detachment and rod buckling.

10. The method for determining the wellbore remediation potential coefficient according to claim 9, characterized in that: The method for determining the proportion of each pump inspection factor in the pump inspection problem in which it is located includes: The proportion of the second pump inspection reason = the number of wells corresponding to the pump inspection factor / the total number of pump inspection wells corresponding to the pump inspection problem of the pump inspection factor; And / or, the method for determining the second potential coefficient corresponding to each pump inspection factor of each pump inspection problem of each type of well based on the second pump inspection reason proportion, the target pump inspection cycle, and the actual pump inspection cycle includes: Where, the target pump inspection period and the actual pump inspection period are the target pump inspection period and the actual pump inspection period corresponding to the type of well where the pump inspection factor is located.

Images