Method for determining optimal adjustment stroke frequency of well with insufficient liquid supply

Abstract

The invention belongs to the technical field of sucker-rod pump oil extraction processes, and discloses a method for determining the optimal adjustment stroke frequency of a well with insufficient liquid supply. Comprising the steps of recording an actual indicator diagram on site, calculating fullness coefficients, calculating stroke frequencies under different fullness coefficients, making a fullness coefficient-stroke frequency relation table, drawing a fullness coefficient-stroke frequency relation curve according to the fullness coefficient-stroke frequency relation table, analyzing the fullness coefficient-stroke frequency relation curve, finding out a change rule and guiding on-site pump condition management. The method is high in pertinence, simple, rapid, accurate and suitable for all wells with insufficient liquid supply, and has wide application prospects.

Description

Technical Field

[0001] This invention belongs to the field of rod pump oil production technology, specifically relating to a method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply. Background Technology

[0002] Due to unreasonable operating procedures, dynamometer card tests showed insufficient fluid supply in some pumping wells. To improve system efficiency and reduce energy consumption, various oilfields have promoted the use of rod pump optimization design software. For the issue of pumping system depletion, an adaptive intelligent oil production control system has been adopted to achieve remote, real-time, efficient, dynamically adjustable, and flexible intermittent oil production control. Even after optimization using the rod pump optimization software, some wells still exhibit insufficient fluid supply. For these wells, adjusting the pump stroke frequency to improve pump efficiency and reduce energy consumption has been implemented, and the widespread use of frequency converters has made adjusting the stroke frequency simpler. However, there is currently no simple and quick method to determine the optimal stroke frequency, often requiring multiple adjustments on-site, increasing workload. While the intermittent oil production control system effectively solves the problems of low system efficiency and high energy consumption in wells with severe fluid supply deficiencies, it has limitations due to high initial investment per well, frequent well equipment failures, and freezing and blockage of surface pipelines in intermittent wells during cold winters in northern regions. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply. It utilizes measured dynamometer cards to quickly determine the optimal adjustment stroke frequency, ensuring continuous production of the pumping unit well under low energy consumption. Reducing the stroke frequency decreases the number of pipe and rod contacts, reducing pipe and rod wear and metal filings. Simultaneously, it reduces the number of opening and closing operations of the traveling valve and fixed valve, reducing collision wear on the ball and seat. This reduces the probability of pipe leakage, rod breakage, metal filings causing pump jamming, and pump leakage, extending the pump inspection cycle.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: a method for determining the optimal adjustment flushing frequency for wells with insufficient fluid supply, comprising the following steps:

[0005] 1. Record the actual dynamometer diagram on site;

[0006] 2. Calculate the filling coefficient;

[0007] 3. Calculate the number of strokes under different fill coefficients and create a table showing the relationship between fill coefficient and number of strokes;

[0008] 4. Based on the table of filling coefficient-strokes, draw the curve of filling coefficient-strokes.

[0009] 5. Analyze the filling coefficient-stroke relationship curve to identify the changing patterns and guide on-site pump condition management.

[0010] Furthermore, step 2 specifically involves: using the measured dynamometer diagram to read the stroke, number of strokes, effective piston stroke, and stroke loss, and calculating the fill factor.

[0011] Furthermore, step 3 specifically involves: under the condition that the output of the work chart remains unchanged, using the formula: n2=(s1×n1) / (β×SP) to calculate the number of strokes under different full-fill coefficients and to create a full-fill coefficient-stroke relationship table;

[0012] In the formula: n2 --- the number of strokes to be adjusted, min -1 ;

[0013] n1 --- Measured dynamometer pulses, min -1 ;

[0014] s1---Measured effective stroke of the plunger on the dynamometer diagram, in meters;

[0015] SP---Measured dynamometer diagram of piston stroke, in meters.

[0016] Furthermore, in the analysis process of step 5, based on the relationship curve between the filling coefficient and the number of strokes, the change in the number of strokes (the decrease in value) is divided into three regions: the filling coefficient is 0.1-0.3, the change in the number of strokes is the largest (the decrease in value is the largest); the filling coefficient is 0.3-0.6, the change in the number of strokes is relatively large (the decrease in value is relatively large); and the filling coefficient is 0.6-0.1, the change in the number of strokes is the smallest (the decrease in value is the smallest).

[0017] Under otherwise unchanged conditions, stroke rate is the only factor affecting power consumption. Decreasing stroke rate increases the fill factor, and power consumption decreases accordingly. Using three energy consumption zones guides on-site pump management, achieving scientific well management. In the high energy consumption zone (fill factor 0.1-0.3), the stroke rate variation with the fill factor is the largest (maximum decrease in stroke rate). Pumps should not operate in this zone; reducing stroke rate or adjusting pump diameter during inspections can help move the fill factor out of this zone. In the medium energy consumption zone (fill factor 0.3-0.6), the stroke rate variation with the fill factor is relatively large (relatively large decrease in stroke rate). In the low energy consumption zone (fill factor 0.6-1), the stroke rate variation with the fill factor is small (small decrease in stroke rate). Pumps should operate in this zone for the lowest energy consumption.

[0018] If the pumping well is not in the low-energy consumption zone, the optimal adjustment stroke frequency for the well with insufficient fluid supply can be quickly determined using the formula: n2=(s1×n1) / (β×SP) to make it operate in this range; if adjusting the stroke frequency still cannot make it in the low-energy consumption zone, the pump diameter should be reduced to make it operate in the low-energy consumption zone.

[0019] The beneficial effects of this invention compared with the prior art are as follows: This invention eliminates various influencing factors such as pump diameter, pump hanger, tubing structure, tubing leakage, crude oil viscosity, water content, oil pressure, casing pressure, pumping unit structure, and pumping unit size. The three power consumption zones (high energy consumption zone, medium energy consumption zone, and low energy consumption zone) and the optimal adjustment stroke formula are only related to the pump filling coefficient. This invention is highly targeted, simple, fast, and accurate, suitable for all wells with insufficient fluid supply, and has broad application prospects. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is the measured dynamometer diagram of well number 66-1-11 in Embodiment 1 of the present invention;

[0022] Figure 2 This is a curve showing the relationship between the filling coefficient and the number of strokes in Embodiment 1 of the present invention;

[0023] Figure 3 This is a graph showing the relationship between the filling coefficient and the number of strokes in Embodiment 1 of the present invention. Detailed Implementation

[0024] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0025] Example 1

[0026] A method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply

[0027] 1. Calculate the number of strokes under different fill coefficients based on the measured dynamometer diagram.

[0028] Based on the measured dynamometer diagram, the stroke loss is 0.36m, the effective plunger stroke is 1m, and the calculated plunger stroke is 2.64m, with a fill factor of 0.38. The number of strokes under different fill factors is calculated using the formula: n2=(s1×n1) / (β×SP), as shown in the table below:

[0029] Table 1. Relationship between Fill Coefficient and Stroke Count

[0030]

[0031]

[0032] 2. Plot the fill coefficient-stroke relationship curve: Based on the data in the table above, the following fill coefficient-stroke relationship curve is obtained: Figure 2 ;

[0033] 3. Curve Analysis: The calculated stroke data under different filling coefficients are processed to obtain the curve showing the relationship between the filling coefficient and the number of strokes, as shown below. Figure 3 .

[0034] Based on the relationship curve between the filling coefficient and the number of strokes, the change in the number of strokes (the decrease in value) is divided into three regions: the filling coefficient is 0.1-0.3, the change in the number of strokes is the largest (the decrease in value is the largest); the filling coefficient is 0.3-0.6, the change in the number of strokes is relatively large (the decrease in value is relatively large); and the filling coefficient is 0.6-0.1, the change in the number of strokes is the smallest (the decrease in value is the smallest).

[0035] Under otherwise unchanged conditions, stroke rate is the only factor affecting power consumption. Decreasing stroke rate increases the fill factor, and power consumption decreases accordingly. Using three energy consumption zones guides on-site pump management, achieving scientific well management. In the high energy consumption zone (fill factor 0.1-0.3), the stroke rate variation with the fill factor is the largest (maximum decrease in stroke rate). Pumps should not operate in this zone; reducing stroke rate or adjusting pump diameter during inspections can help move the fill factor out of this zone. In the medium energy consumption zone (fill factor 0.3-0.6), the stroke rate variation with the fill factor is relatively large (relatively large decrease in stroke rate). In the low energy consumption zone (fill factor 0.6-1), the stroke rate variation with the fill factor is small (small decrease in stroke rate). Pumps should operate in this zone for the lowest energy consumption.

[0036] If the pumping well is not in the low-energy consumption zone, the optimal adjustment stroke frequency for the well with insufficient supply can be quickly determined using the formula: n2=(s1×n1) / (β×SP) to make it operate in this range; if adjusting the stroke frequency still cannot make it in the low-energy consumption zone, the pump diameter should be reduced to make it operate in the low-energy consumption zone.

[0037] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply, characterized in that, The steps are: S1. Record the actual dynamometer diagram on site; S2. Calculate the filling coefficient; S3. Calculate the number of strokes under different full-fill coefficients and create a table showing the relationship between full-fill coefficient and number of strokes; S4. Based on the table of filling coefficient-stroke relationship, draw the curve of filling coefficient-stroke relationship; S5. Analyze the filling coefficient-stroke relationship curve to find the changing pattern and guide on-site pump condition management.

2. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 1, characterized in that, Step S2 specifically involves: using the measured dynamometer diagram to read the stroke, number of strokes, effective piston stroke, and stroke loss, and calculating the fullness coefficient.

3. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 1, characterized in that, Specifically, step S3 involves: under the condition that the output of the work chart remains unchanged, using the formula: n2=(s1×n1) / (β×SP) to calculate the number of strokes under different full-fill coefficients and to create a full-fill coefficient-stroke relationship table; In the formula: n2 --- the number of strokes to be adjusted, min -1 ; n1 --- Measured dynamometer pulses, min -1 ; s1---Measured effective stroke of the plunger on the dynamometer diagram, in meters; SP---Measured dynamometer diagram of piston stroke, in meters.

4. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 1, characterized in that, In the analysis process of step S5, the change in the number of strokes is divided into three regions according to the relationship curve between the filling coefficient and the number of strokes.

5. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 4, characterized in that, The division of the three zones is specifically based on the fill coefficient.

6. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 5, characterized in that, The method of dividing by the filling coefficient is as follows: filling coefficient 0.1-0.3; filling coefficient 0.3-0.6; filling coefficient 0.6-1.

7. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 6, characterized in that, A fill factor of 0.1-0.3 indicates the maximum variation in stroke count.

8. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 6, characterized in that, A fill factor of 0.3-0.6 indicates a large variation in stroke count.

9. The method for determining the optimal adjustment stroke frequency for wells with insufficient fluid supply according to claim 6, characterized in that, A fill factor of 0.6-1 represents the minimum change in stroke rate.

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