Test method for sensing operation position and speed of plunger

Abstract

The invention discloses a testing method for sensing the running position and speed of a plunger, which comprises the following steps: synchronously acquiring pressure, temperature and acceleration data by sensing the plunger, and acquiring the data with time scales; filtering high-frequency signals from the collected acceleration data by using a low-pass filter; an acceleration curve after filtering is drawn, an optimal pulse peak point is selected for a double-pulse peak signal appearing at the hoop position through an algorithm, the number of the optimal pulse peaks is recorded as K, and the number of the hoop points is the same as the number of the optimal pulse peaks; according to the well depth structure, the average speed vn of the plunger passing through the nth oil pipe and the position depth Sn corresponding to the nth coupling point are calculated; according to the method, the influence of the double-pulse peak signal can be eliminated, and the operation position and speed of the plunger can be accurately calculated, measured and sensed.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas well production control, and in particular to a testing method for sensing a plunger running position and speed. Background Art

[0002] The sensing plunger has the function of draining water and producing gas, and can also monitor parameters such as pressure and temperature during the operation of the plunger. It is crucial to the formulation of the plunger drainage and gas production system. However, the tested pressure and temperature data fail to correspond to the well depth, affecting the accurate analysis of gas well workers.

[0003] Since the plunger moves up and down in the wellbore at a non-uniform speed, and the plunger seater at the bottom of the well moves during production, the depth position of the plunger during operation cannot be calculated by combining uniform motion with the seater depth. In addition, the depth position is calculated by sensing the temperature and pressure curves of the plunger test and combining the pressure gradient curve of the well. The shortcomings are: a. The pressure gradient curve needs to be obtained by testing the pressure gauge in advance, which increases the operating cost; b. The plunger moves up very fast, and there is a serious lag in the temperature test. The gas-liquid state in the wellbore during production is discontinuous and unstable, and the error of the pressure gradient calculation result is large. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a test method for sensing the running position and speed of the plunger, which can accurately calculate and measure the running position and speed of the plunger and has universal applicability.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: a testing method for sensing the running position and speed of a plunger, comprising the following steps:

[0006] S1, sensing the acceleration data of the plunger with time scale synchronously during the downward movement of the plunger in the oil pipe;

[0007] S2, using a low-pass filter to filter out high-frequency signals from the collected acceleration data;

[0008] S3, draw the acceleration curve after filtering, select the optimal pulse peak point for the double pulse peak signal appearing at the butt collar position through an algorithm, and record the optimal pulse peak number as K, the number of collar points is the same as the optimal pulse peak number;

[0009] S4. According to the well depth structure, set the length of the nth oil pipe to L. n , set the time to pass through the nth oil pipe as t n , calculate the average speed v of the plunger passing through the nth oil pipe n ;

[0010] S5. According to the well depth structure, the depth S corresponding to the nth coupling point is calculated by accumulating the length of the tubing. n .

[0011] The algorithm in step S3 specifically includes the following steps:

[0012] S31, manually select the starting pulse peak point in the acceleration curve as the first pulse peak point P0, P0 = {t0, w0, h0}, where t0 is the time point of the first pulse peak point, w0 is the pulse peak width of the first pulse peak point, h0 is the pulse peak amplitude of the first pulse peak point, assign t0 = 0, i = 1, P i =b,P i is the i-th optimal pulse peak point;

[0013] S32, intercepting data segment a[W] according to the window width W;

[0014] S33, in the data segment a[W], determine whether the middle point data3 is greater than or equal to the first two points and the last two points, if not, return to the previous step;

[0015] S34, detect that there are n measured pulse peak points in the window, n≥1, and compare the width and amplitude of the measured pulse peak points, determine that the largest one is the optimal pulse peak point of this window, if there are the same, take the former, and assign b={t, w, h}, t is the time point of the optimal pulse peak point of the window, w is the pulse peak width of the optimal pulse peak point of the window, h is the pulse peak amplitude of the optimal pulse peak point of the window, and assign i=i+1;

[0016] S35. Repeat steps S32 to S34 until the end point of the acceleration curve is reached.

[0017] The average speed v in step S4 n The specific calculation formula is: n＝ L n / (t n -t n-1 ), where n ranges from 1 to K.

[0018] The position depth S in step S5 n The specific calculation formula is: The value range of n is 1 to K.

[0019] When the sensing plunger moves upward in the oil pipe, steps S1 to S5 are repeated to obtain upward speed and position data.

[0020] Beneficial effects of the present invention: Compared with the prior art, the present invention analyzes the acceleration curve. When a double pulse peak signal appears at the coupling position, a[w] is intercepted in the window width w, and a suitable measurement pulse is selected based on the comparison. Finally, the pulse with the largest width and amplitude is taken as the window pulse, eliminating the influence of the double pulse peak, so that the calculation, measurement and perception of the plunger running position and speed are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings:

[0022] Figure 1 is a flow chart of the present invention;

[0023] Figure 2 is a flow chart of S3 in the present invention;

[0024] Figure 3 It is a curve diagram of the filtering of the acceleration signal of the plunger passing through the coupling;

[0025] Figure 4 It is a curve diagram of the parameters of the downward movement process of the sensing plunger;

[0026] Figure 5 It is a curve diagram of the parameters of the upward movement process of the sensing plunger. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0029] Example

[0030] like Figures 1 to 4 As shown, the present invention provides a testing method for sensing the running position and speed of a plunger, comprising the following steps:

[0031] S1, sensing the acceleration data of the plunger with time scale synchronously during the downward movement of the plunger in the oil pipe;

[0032] S2. A low-pass filter is used to filter out high-frequency signals from the collected acceleration data; after filtering, the characteristic acceleration signal generated by the impact when the plunger passes through the oil pipe coupling can be highlighted;

[0033] S3, draw the acceleration curve after filtering, select the optimal pulse peak point for the double pulse peak signal appearing at the butt collar position through an algorithm, and record the optimal pulse peak number as K, the number of collar points is the same as the optimal pulse peak number;

[0034] S4. According to the well depth structure, set the length of the nth oil pipe to L. n , set the time to pass through the nth oil pipe as t n , calculate the average speed v of the plunger passing through the nth oil pipe n ;

[0035] S5. According to the well depth structure, the depth S corresponding to the nth coupling point is calculated by accumulating the length of the tubing. n .

[0036] like Figure 4 As shown, the sensing plunger can also synchronously collect pressure and temperature data during its downward movement.

[0037] like Figure 2 As shown, the algorithm in step S3 specifically includes the following steps:

[0038] S31, manually select the starting pulse peak point in the acceleration curve as the first pulse peak point P0, P0 = {t0, w0, h0}, where t0 is the time point of the first pulse peak point, w0 is the pulse peak width of the first pulse peak point, h0 is the pulse peak amplitude of the first pulse peak point, assign t0 = 0, i = 1;

[0039] S32, intercepting data segment a[W] according to the window width W;

[0040] S33, in the data segment a[W], determine whether the middle point data3 is greater than or equal to the first two points and the last two points, if not, return to the previous step;

[0041] S34, detect that there are n measured pulse peak points in the window, n ≥ 1, and compare the width and amplitude of the measured pulse peak points, determine that the largest one is the optimal pulse peak point in this window, if there are the same, take the former, and assign b = {t, w, h}, t is the time point of the optimal pulse peak point in the window, w is the pulse peak width of the optimal pulse peak point in the window, h is the pulse peak amplitude of the optimal pulse peak point in the window, assign i = i + 1, P i =b,P i is the i-th optimal pulse peak point;

[0042] S35. Repeat steps S32 to S34 until the end point of the acceleration curve is reached.

[0043] The average speed v in step S4 n The specific calculation formula is:n＝ L n / (t n -t n-1 ), where n ranges from 1 to K.

[0044] The position depth S in step S5 n The specific calculation formula is: The value range of n is 1 to K.

[0045] By analyzing the acceleration curve, when a double pulse peak signal appears at the coupling position, a[w] is intercepted in the window width w, and the appropriate measurement pulse is selected based on the comparison. Finally, the pulse with the largest width and amplitude is taken as the window pulse to eliminate the influence of the double pulse peak, making the calculation, measurement and perception of the plunger running position and speed more accurate.

[0046] like Figure 5 As shown, during the upward movement of the sensing plunger in the oil pipe, steps S1 to S5 are repeated to obtain the upward speed and position data, and the temperature and pressure data can be collected synchronously.

[0047] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A testing method for sensing the running position and speed of a plunger, characterized in that: The steps include: S1, sensing the acceleration data of the plunger with time scale synchronously during the downward movement of the plunger in the oil pipe; S2, using a low-pass filter to filter out high-frequency signals from the collected acceleration data; S3, draw the acceleration curve after filtering, select the optimal pulse peak point for the double pulse peak signal appearing at the butt collar position through an algorithm, and record the optimal pulse peak number as K, the number of collar points is the same as the optimal pulse peak number; S4. According to the well depth structure, set the length of the nth oil pipe to L. n , set the time to pass through the nth oil pipe as t n , calculate the average speed v of the plunger passing through the nth oil pipe n ; S5. According to the well depth structure, the depth S corresponding to the nth coupling point is calculated by accumulating the length of the tubing. n .

2. A testing method for sensing the running position and speed of a plunger according to claim 1, characterized in that: The algorithm in step S3 specifically includes the following steps: S31, manually select the starting pulse peak point in the acceleration curve as the first pulse peak point P0, P0 = {t0, w0, h0}, where t0 is the time point of the first pulse peak point, w0 is the pulse peak width of the first pulse peak point, h0 is the pulse peak amplitude of the first pulse peak point, assign t0 = 0, i = 1; S32, intercepting data segment a[W] according to the window width W; S33, in the data segment a[W], determine whether the middle point data3 is greater than or equal to the first two points and the last two points, if not, return to the previous step; S34, detect that there are n measured pulse peak points in the window, n ≥ 1, and compare the width and amplitude of the measured pulse peak points, determine that the largest one is the optimal pulse peak point in this window, if there are the same, take the former, and assign b = {t, w, h}, t is the time point of the optimal pulse peak point in the window, w is the pulse peak width of the optimal pulse peak point in the window, h is the pulse peak amplitude of the optimal pulse peak point in the window, assign i = i + 1, P i =b,P i is the i-th optimal pulse peak point; S35. Repeat steps S32 to S34 until the end point of the acceleration curve is reached.

3. A testing method for sensing the running position and speed of a plunger according to claim 1, characterized in that: The average speed v in step S4 n The specific calculation formula is: n＝ L n / (t n -t n-1 ), where n ranges from 1 to K.

4. A testing method for sensing the running position and speed of a plunger according to claim 1, characterized in that: The position depth S in step S5 n The specific calculation formula is: The value range of n is 1 to K.

5. A testing method for sensing the running position and speed of a plunger according to claim 1, characterized in that: When the sensing plunger moves upward in the oil pipe, steps S1 to S5 are repeated to obtain upward speed and position data.

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