Method for drawing and using diagnosis image of eccentric wear risk of underground rod tube of oil pumping unit

Abstract

The invention discloses a method for drawing and using a diagnostic image of an eccentric wear risk of an underground rod tube of a pumping unit, and belongs to the technical field of visual diagnostic tools of the eccentric wear risk of the rod tube. The method includes the following steps that firstly, the operation stroke frequency of the oil pumping unit is obtained; 2, determining the lateral contact force of the rod and the pipe of the oil pumping unit; 3, performing dimensionless treatment on the lateral contact force and the operation stroke frequency of the oil pumping unit; 4, establishing a coordinate system, and loading the data subjected to dimensionless processing to the coordinate system to form an eccentric wear risk diagnosis image; and 5, evaluating the eccentric wear risk of the rod tube according to the eccentric wear risk diagnosis image, and proposing a coping strategy. The method has the beneficial effects that the rod and pipe eccentric wear risk diagnosis diagram provided by the invention can evaluate the rod and pipe eccentric wear reasons in time and guide the adjustment of an anti-eccentric wear technology, the proportion of a safe area is expanded, and the repair-free period of an oil well is prolonged.

Description

Technical Field

[0001] This invention relates to a diagnostic image drawing and usage method for the risk of rod and tubing wear in downhole pumping units, belonging to the technical field of visual diagnostic tools for rod and tubing wear risk. Background Technology

[0002] Oil well failures necessitate well workover maintenance. Uneven wear between the sucker rod and tubing is a major cause of well failures and a significant impact on the maintenance-free period, accounting for more than half of all workovers. Developing an effective anti-wear technology that is both technically and economically suitable is crucial for extending the wear cycle. Previously, a reactive approach was adopted, summarizing historical workover data on wear cycles, locations, and morphologies to dynamically adjust anti-wear technologies for the maintenance-free period. However, this approach, adjusting anti-wear technology after a well failure has occurred, is essentially a trial-and-error method with long evaluation cycles, delayed guidance, and poor anti-wear effectiveness. Summary of the Invention

[0003] To address the lag in the evaluation of causes and technical support for oil well wear, a visual diagnostic tool has been invented to evaluate the risk and causes of rod and tubing wear based on the operating conditions of the oil well. This tool can predict the risk of rod and tubing wear and adjust anti-wear technical countermeasures accordingly, thus shifting from post-event summary to pre-event prediction.

[0004] Under the same operating conditions, the wear degree of sucker rod tubing depends on the lateral contact force and the number of strokes. The lateral contact force determines the amount of wear per stroke; the greater the lateral contact force, the greater the amount of wear per stroke. The number of strokes determines the total number of wear cycles; the faster the strokes, the more wear cycles in total. Based on the principle of rod tubing wear, considering both lateral contact force and the number of strokes, a risk diagnosis chart for rod tubing wear in sucker wells is used to evaluate the causes of rod tubing wear and guide adjustments to anti-wear techniques.

[0005] The technical solution of this invention is: a method for drawing and using diagnostic images of downhole tubing wear risk in oil pumping units, comprising the following steps:

[0006] Step 1: Obtain the number of pumping unit operating strokes;

[0007] Step 2: Determine the magnitude of the lateral contact force on the pumping unit rod tube;

[0008] Step 3: Dimensionless processing of lateral contact force and pumping unit operating strokes;

[0009] Step 4: Establish a coordinate system and load the dimensionless data onto the coordinate system to form a wear risk diagnosis image;

[0010] Step 5: Based on the wear risk diagnosis image, evaluate the wear risk of the rod and tube and propose corresponding strategies.

[0011] Step one specifically involves collecting dynamic data on oil well production and obtaining the number of pumping unit strokes.

[0012] Step two specifically involves dividing the wellbore trajectory into several segments with a certain step length, calculating the lateral contact force of the rod and tubing longitudinally along each segment, and selecting the maximum value as the magnitude of the lateral contact force of the rod and tubing in this well.

[0013] The formula for calculating the lateral contact force of the rod tube along the longitudinal direction of the sucker rod string is as follows:

[0014]

[0015] In equation (1), N i p represents the lateral contact force of the rod and tubing in any section of the well, expressed in N / m. i R represents the sucker rod load in any well section, in N (Newtons). i The radius of curvature of the projection of any section of the wellbore axis onto the vertical plane, in meters (m); r i is the radius of curvature of any section of the wellbore axis projected onto the horizontal plane, in meters; S is the pumping unit stroke, in meters; n is the pumping unit strokes per minute; f ri This represents the cross-sectional area of ​​the sucker rod for any well section, in meters (m²). 2 ;ρ s This refers to the density of the sucker rod material, expressed in kg / m³. 3 ;α vi This represents the average well inclination angle at both ends of any well section, in degrees.

[0016] The lateral contact force and the number of pumping unit operating strokes are dimensionless according to the following formula:

[0017]

[0018] In equations (2) and (3), N′ mj N represents the dimensionless lateral contact force of the j-th well, which is dimensionless. mj The lateral contact force of the j-th well is expressed in N / m; N Max n′ represents the maximum lateral contact force for all wells, in N / m. j For the dimensionless stroke of the j-th well, n is dimensionless; j The number of strokes for the j-th well is expressed in strokes per minute; n Max This represents the maximum number of well strokes across all wells, expressed in strokes per minute.

[0019] Step four is as follows: Using the dimensionless stroke rate of the oil well as the horizontal axis and the dimensionless lateral contact force of the rod and tube as the vertical axis, load all the dimensionless data points of the oil wells onto the coordinate system, and divide the graph into four regions: the safe zone, the stroke abnormal zone, the stress abnormal zone, and the danger zone.

[0020] If the dimensionless lateral contact force and dimensionless stroke count in the safe zone are <0.5 and <0.5 respectively, and the actual data point of the oil well falls within the safe zone, it means that the risk of rod and tubing wear is low and the current production status can be maintained.

[0021] In the abnormal stroke zone, the dimensionless lateral contact force is <0.5 and the dimensionless stroke is ≥0.5. If the actual data point of the oil well falls in the abnormal stroke zone, it means that the stroke is too fast and the risk of rod and tubing wear is high. The operating stroke should be reduced.

[0022] In the abnormal stress zone, the dimensionless lateral contact force is ≥0.5 and the dimensionless stroke is <0.5. If the actual data point of the oil well falls in the abnormal stress zone, it means that the lateral contact force is too large, which leads to a high risk of rod and tube wear. Measures should be taken to reduce the lateral contact force, including increasing the rod and tube clearance.

[0023] If the dimensionless lateral contact force in the danger zone is ≥0.5 and the dimensionless stroke rate is ≥0.5, and the actual data point of the oil well falls in the danger zone, it indicates a high risk of rod and tubing wear. The stroke rate and lateral contact force should be reduced simultaneously.

[0024] The beneficial effects of the present invention are as follows: The rod and tube wear risk diagnosis map proposed in this invention can evaluate the causes of rod and tube wear in a timely manner and guide the adjustment of anti-wear technology, expand the proportion of safe zone, and extend the maintenance-free period of oil wells. Attached Figure Description

[0025] Figure 1 Diagram for risk diagnosis of rod and tubing wear in oil pumping units;

[0026] Figure 2 This is a diagnostic diagram of the risk of uneven wear on the rod and tubing of the pumping unit after treatment. Detailed Implementation

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0031] Example 1

[0032] A method for creating and using diagnostic images of downhole tubing wear risk in oil pumping units, comprising the following steps:

[0033] Step 1: Collect dynamic data on oil well production and obtain the number of pumping unit operating strokes;

[0034] Step 2: Divide the wellbore trajectory into several segments according to a certain step length, calculate the lateral contact force of the rod and tubing in the longitudinal direction of the sucker rod string for each segment, and select the maximum value as the magnitude of the lateral contact force of the rod and tubing in this well.

[0035] The formula for calculating the lateral contact force of the rod tube along the longitudinal direction of the sucker rod string is as follows:

[0036]

[0037] In equation (1), N i p represents the lateral contact force of the rod and tubing in any section of the well, expressed in N / m. i R represents the sucker rod load in any well section, in N (Newtons). i The radius of curvature of the projection of any section of the wellbore axis onto the vertical plane, in meters (m); r i is the radius of curvature of any section of the wellbore axis projected onto the horizontal plane, in meters; S is the pumping unit stroke, in meters; n is the pumping unit strokes per minute; f ri This represents the cross-sectional area of ​​the sucker rod for any well section, in meters (m²). 2 ;ρ s This refers to the density of the sucker rod material, expressed in kg / m³. 3 ;α vi This represents the average well inclination angle at both ends of any well section, in degrees.

[0038] Step 3: Dimensionless processing of the lateral contact force and the number of pumping unit strokes is performed according to the following formula:

[0039]

[0040] In equations (2) and (3), N′ mj N represents the dimensionless lateral contact force of the j-th well, which is dimensionless. mj The lateral contact force of the j-th well is expressed in N / m; N Max n′ represents the maximum lateral contact force for all wells, in N / m.j For the dimensionless stroke of the j-th well, n is dimensionless; j The number of strokes for the j-th well is expressed in strokes per minute; n Max This represents the maximum number of well strokes, expressed in strokes per minute.

[0041] Step 4: Establish a coordinate system with dimensionless stroke frequency of the oil well as the x-axis and dimensionless rod and tube lateral contact force as the y-axis. Load all the dimensionless data points of the oil wells onto the coordinate system and divide the graph into four regions: safe zone, stroke abnormal zone, stress abnormal zone and danger zone, to form a wear risk diagnosis image.

[0042] Step 5: Based on the wear risk diagnosis image, evaluate the wear risk of the rod and tube and propose corresponding strategies.

[0043] If the dimensionless lateral contact force and dimensionless stroke count in the safe zone are <0.5 and <0.5 respectively, and the actual data point of the oil well falls within the safe zone, it means that the risk of rod and tubing wear is low and the current production status can be maintained.

[0044] In the abnormal stroke zone, the dimensionless lateral contact force is <0.5 and the dimensionless stroke is ≥0.5. If the actual data point of the oil well falls in the abnormal stroke zone, it means that the stroke is too fast and the risk of rod and tubing wear is high. The operating stroke should be reduced.

[0045] In the abnormal stress zone, the dimensionless lateral contact force is ≥0.5 and the dimensionless stroke is <0.5. If the actual data point of the oil well falls in the abnormal stress zone, it means that the lateral contact force is too large, which leads to a high risk of rod and tube wear. Measures should be taken to reduce the lateral contact force, including increasing the rod and tube clearance.

[0046] If the dimensionless lateral contact force in the danger zone is ≥0.5 and the dimensionless stroke rate is ≥0.5, and the actual data point of the oil well falls in the danger zone, it indicates a high risk of rod and tubing wear. The stroke rate and lateral contact force should be reduced simultaneously.

[0047] Example 2

[0048] The following is in conjunction with the appendix Figure 1-2 The present invention will be described in further detail as follows:

[0049] Evaluation of the risk of rod and tube wear in a certain oilfield block

[0050] A certain block has a total of 40 oil wells. The risk diagnosis chart of rod and tubing wear in pumping wells is used to evaluate the causes of rod and tubing wear in a timely manner and guide the adjustment of anti-wear technology.

[0051] (1) Collect production dynamic data from 40 oil wells and obtain the number of pumping unit strokes.

[0052] (2) Divide the wellbore trajectory into several segments according to a certain step length, and calculate the longitudinal lateral contact force N of the sucker rod string according to formula (1). i Select the maximum value N. m This represents the magnitude of the lateral contact force in this well. The same method was used to obtain the lateral contact forces of 40 oil wells.

[0053] (3) The lateral contact force and pumping unit operating stroke of 40 oil wells were dimensionless according to Equations (2) and (3). The specific data are shown in Table 1.

[0054] Table 1 Data from 40 wells in a certain block

[0055]

[0056]

[0057] (4) Using dimensionless stroke count as the abscissa and dimensionless rod and tubing lateral contact force as the ordinate, load all dimensionless data points of all oil wells onto the coordinate system, and divide the graph into four regions: safe zone, stroke anomaly zone, stress anomaly zone, and danger zone. For example... Figure 1 As shown.

[0058] (5) Evaluate the risk of rod and tubing wear based on the region where the oil well is located and propose mitigation measures.

[0059] (5-1) The actual data points of 14 oil wells fall within the safe zone, with dimensionless lateral contact force <0.5 and dimensionless stroke <0.5, indicating a low risk of rod and tubing wear, and maintaining the current production status.

[0060] (5-2) The actual data points of 11 oil wells fell within the abnormal stroke rate zone, with dimensionless lateral contact force <0.5 and dimensionless stroke rate ≥0.5, indicating that the excessive stroke rate led to a high risk of rod and tubing wear, and the stroke rate needed to be reduced. Among them, the motor wheel was replaced in 5 wells, and the stroke rate was reduced from an average of 4.5 strokes / min to an average of 2.8 strokes / min;

[0061] (5-3) The actual data points of 4 oil wells fall in the abnormal stress zone, with dimensionless lateral contact force ≥ 0.5 and dimensionless strokes < 0.5, indicating that the excessive lateral contact force leads to a high risk of rod and tubing wear, and it is necessary to reduce the rod and tubing contact force. Among them, the 27 / 8" tubing in 2 wells was replaced with 31 / 2" tubing to increase the rod and tubing clearance and reduce the contact force;

[0062] (5-4) The actual data points of 11 oil wells fall in the danger zone, with dimensionless lateral contact force ≥0.5 and dimensionless stroke rate ≥0.5, indicating a high risk of rod and tubing wear. It is necessary to reduce both stroke rate and lateral contact force. Among them, the motor impeller was replaced in 4 wells, and the stroke rate was reduced from an average of 4.3 strokes / min to an average of 2.8 strokes / min. At the same time, the 27 / 8" tubing was replaced with 31 / 2" tubing to increase the rod and tubing clearance and reduce the contact force.

[0063] (6) Guided by the risk diagnosis chart for rod and tubing wear in pumping unit wells, remediation work has been carried out on 120 wells, increasing the proportion of safe zones from 35% to 62.5% after remediation (e.g., ...). Figure 2 As shown in the figure, the maintenance-free period for oil wells has been increased by 80 days.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for creating and using diagnostic images of downhole tubing wear risk in oil pumping units, characterized in that, Includes the following steps: Step 1: Obtain the number of pumping unit operating strokes; Step 2: Determine the magnitude of the lateral contact force on the pumping unit rod tube; Step 3: Dimensionless processing of lateral contact force and pumping unit operating strokes; Step 4: Establish a coordinate system and load the dimensionless data onto the coordinate system to form a wear risk diagnosis image; Step 5: Based on the wear risk diagnosis image, evaluate the wear risk of the rod and tube and propose corresponding strategies.

2. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 1, characterized in that, Step one specifically involves collecting dynamic data on oil well production and obtaining the number of pumping unit strokes.

3. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 1, characterized in that, Step two specifically involves dividing the wellbore trajectory into several segments with a certain step length, calculating the lateral contact force of the rod and tubing longitudinally along each segment, and selecting the maximum value as the magnitude of the lateral contact force of the rod and tubing in this well.

4. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 3, characterized in that, The formula for calculating the lateral contact force of the rod tube along the longitudinal direction of the sucker rod string is as follows: In equation (1), N i p represents the lateral contact force of the rod and tubing in any section of the well, expressed in N / m. i R represents the sucker rod load in any well section, in N (Newtons). i The radius of curvature of the projection of any section of the wellbore axis onto the vertical plane, in meters (m); r i The radius of curvature of any section of the wellbore axis projected onto the horizontal plane is given in meters. S represents the pumping unit stroke, in meters (m); n represents the pumping unit strokes per minute (strokes / minute); f ri This represents the cross-sectional area of ​​the sucker rod for any well section, in meters (m²). 2 ; ρ s This refers to the density of the sucker rod material, expressed in kg / m³. 3 ;α vi This represents the average well inclination angle at both ends of any well section, in degrees.

5. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 1, characterized in that, The lateral contact force and the number of pumping unit operating strokes are dimensionless according to the following formula: In equations (2) and (3), N′ mj N represents the dimensionless lateral contact force of the j-th well, which is dimensionless. mj The lateral contact force of the j-th well is expressed in N / m; N Max n′ represents the maximum lateral contact force for all wells, in N / m. j For the dimensionless stroke of the j-th well, n is dimensionless; j The number of strokes for the j-th well is expressed in strokes per minute; n Max This represents the maximum number of well strokes across all wells, expressed in strokes per minute.

6. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 1, characterized in that, Step four is as follows: Using the dimensionless stroke rate of the oil well as the horizontal axis and the dimensionless lateral contact force of the rod and tube as the vertical axis, load all the dimensionless data points of the oil wells onto the coordinate system, and divide the graph into four regions: the safe zone, the stroke abnormal zone, the stress abnormal zone, and the danger zone.

7. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 6, characterized in that, If the dimensionless lateral contact force and dimensionless stroke count in the safe zone are <0.5 and <0.5 respectively, and the actual data point of the oil well falls within the safe zone, it means that the risk of rod and tubing wear is low and the current production status can be maintained.

8. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 6, characterized in that, In the abnormal stroke zone, the dimensionless lateral contact force is <0.5 and the dimensionless stroke is ≥0.

5. If the actual data point of the oil well falls in the abnormal stroke zone, it means that the stroke is too fast and the risk of rod and tubing wear is high. The operating stroke should be reduced.

9. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 6, characterized in that, In the abnormal stress zone, the dimensionless lateral contact force is ≥0.5 and the dimensionless stroke is <0.

5. If the actual data point of the oil well falls in the abnormal stress zone, it means that the lateral contact force is too large, which leads to a high risk of rod and tube wear. Measures should be taken to reduce the lateral contact force, including increasing the rod and tube clearance.

10. The method for drawing and using diagnostic images of downhole tubing wear risk in pumping units according to claim 6, characterized in that, If the dimensionless lateral contact force in the danger zone is ≥0.5 and the dimensionless stroke rate is ≥0.5, and the actual data point of the oil well falls in the danger zone, it indicates a high risk of rod and tubing wear. The stroke rate and lateral contact force should be reduced simultaneously.

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