Beam-pumping unit balance parameter design method
By designing the balance parameters of the swimming beam oil pumping machine with equal torque sets, the problems of instability of the oil pumping machine and low power for motors are solved, and the torque balance and stability are improved.
Patent Information
- Application Number
- CN202311696819.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-11
- Publication Date
- 2025-06-13
AI Technical Summary
When designing balance parameters of existing gaze beam oil pumps, it is easy to cause unstable oil pumps, large inertia swing, and large back electromotive force in the motor, resulting in low power usage and large energy loss, affecting the motor life.
By the method of equal set of torques of the forearm and rear arm of the swimming beam, the number and size of the balance blocks and the installation position on the crank are designed to maximize the balance block gravity moment and the load torque of the oil pump bar during the entire operation.
The torque balance of the sway beam type oil pump during operation is realized, which reduces inertial swing, improves the stability of the oil pump and the power of the motor, reduces energy loss, and extends the motor life.
Smart Images
Figure CN120145566A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of pumping units for oilfield development, and particularly relates to a method for designing balance parameters of a beam pumping unit. Background Art
[0002] In oilfield development, artificial lift is the main production method, and rod pumping lift is the main type of artificial lift, accounting for more than two-thirds. Most of them are beam pumping unit wells. When designing the balance parameters of a beam pumping unit, according to the balance configuration method and the position of the balance weight, it can be divided into three types: beam balance, crank balance, and composite balance. Their characteristics are as follows:
[0003] Beam balance: A balance method in which a certain number of balance weights are added to the tail of the beam. However, this balance method is prone to inertial swing during the movement of the pumping unit, resulting in instability of the pumping unit and having a certain negative impact on the toughness of the beam. Therefore, this method is only applicable to light pumping units with a polished rod load below 30 KN.
[0004] Crank balance: The balance weight is installed on the crank. This method reduces the inertial swing caused by the beam balance method and is applicable to medium and heavy pumping units with a polished rod load above 30 KN. However, there is a large load and centrifugal force on the crank.
[0005] Composite balance: It is a balance method that simultaneously uses the beam balance and crank balance methods on the same beam pumping unit. Its characteristic is that when adjusting the balance within a small range, the beam balance weight can be adjusted; when adjusting the balance within a large range, the crank balance weight is adjusted. This balance method has a large adjustment range and is applicable to medium-sized pumping units.
[0006] The balance measurement mainly uses the current method I and the power method P, and the balance adjustment is mainly the empirical method.
[0007] When the beam pumping unit is lifting, the polished rod of the pumping unit drives the reciprocating movement of the piston of the oil pump in the pump barrel. The load on the upper and lower sides changes continuously during one revolution of its movement. The power system of the pumping unit is a rotational movement. Under the continuously changing load, it will inevitably cause fluctuations in the motor current of the power system. In addition, the pump depth, pump condition, and reservoir fluid of each well are different. Therefore, the balance adjustment implemented by the current empirical method has poor balance effect, large back electromotive force inside the motor, and low useful power, resulting in not only large energy loss but also affecting the motor life. Summary of the Invention
[0008] In view of this, the present invention provides a method for designing balance parameters of a beam pumping unit. By using the method of equal torque sets of the front beam arm and the rear beam arm, through reasonable design of the balance parameters, that is, designing the number and size of the balance weights and their installation positions on the crank, the purpose of maximizing the balance of the gravitational torque of the balance weights and the load torque of the polished rod of the pumping unit throughout the operation process can be achieved.
[0009] To achieve the above object, the present invention adopts the following technical solutions.
[0010] A method for designing balance parameters of a beam pumping unit, comprising the following steps:
[0011] S1: Obtain the basic parameters of the beam pumping unit, including: the mass of the pony head, the distance from the center of gravity of the pony head to the fulcrum of the beam, the mass of the front arm of the beam, the distance from the center of gravity of the front arm of the beam to the fulcrum of the beam, the mass of the rear arm of the beam, the distance from the center of gravity of the rear arm of the beam to the fulcrum of the beam, the mass of the crossbeam, the distance from the center of gravity of the crossbeam to the fulcrum of the beam, the mass of the connecting rod, the distance from the center of gravity of the connecting rod to the fulcrum of the beam, the distance from the bottom end of the connecting rod to the crank rotation axis, the distance from the top end of the connecting rod to the fulcrum of the beam, the distance from the polished rod to the fulcrum of the beam, the mass of the crank, the distance from the center of gravity point of the crank to the crank rotation axis, the mass of the balance weight, the number of balance weights, and take the distance from the center of gravity point of the balance weight to the crank rotation axis as the parameter for adjusting the balance;
[0012] S2: Measure the actual polished rod dynamometer card of the beam pumping unit, determine the four vertices on the dynamometer card, calculate the polished rod load between the vertices by using the median method, and then obtain the polished rod torque M 光杆 value by multiplying the polished rod load by the distance from the polished rod to the fulcrum of the beam;
[0013] S3: Substitute the data measured in S1 and S2 into the formula to obtain the optimal balance parameters; where M 前臂 represents the torque value of the front arm of the beam, M 后臂 represents the torque value of the rear arm of the beam, represents the sum of the torques of the front arm of the beam pumping unit during one up and down operation cycle, represents the sum of the torques of the rear arm of the beam pumping unit during one up and down operation cycle.
[0014] Further, in S2, the four vertices on the dynamometer card are determined at the point with the maximum curvature or the minimum radius of curvature. For example: Figure 1 or Figure 2 the four points A, B, C, and D in.
[0015] Further, in S2, the concave and convex points are also determined according to the comparison between the curve in the actual polished rod dynamometer card and the connection line of the four vertices in the actual dynamometer card. The point where the distance from the curve in the actual polished rod dynamometer card to the connection line is the largest is the concave or convex point. Among them, the curve in the actual polished rod dynamometer card outside each two-vertex connection line is the convex point, and the curve inside the connection line is the concave point; the actual polished rod dynamometer card is divided into several continuous line segments by using the concave points, convex points, and vertices in the actual polished rod dynamometer card, and the polished rod load of each segment is calculated by using the median method.
[0016] Further, in S3, the torque value of the front arm of the beam includes the structural torque value of the front arm of the beam and the polished rod torque value; the torque value of the rear arm of the beam includes the structural torque value of the rear arm of the beam and the connecting rod torque value.
[0017] Further, the structural moment value of the front arm of the walking beam includes the moment value of the polished rod gravity and the moment value of the front arm of the walking beam gravity.
[0018] Further, the structural moment value of the rear arm of the walking beam includes the moment value of the rear arm of the walking beam gravity, the moment value of the cross beam gravity, and the moment values of the connecting rods on both sides.
[0019] Further, the moment value of the connecting rod is calculated by the moment value of the crank and the moment value of the counterweight.
[0020] Further, in step S3, the formula According to the specific mechanism of the beam pumping unit, it is further optimized to
[0021] The beneficial effect of the present invention is that by using the method of making the moment set of the front arm of the walking beam equal to the moment set value of the rear arm of the walking beam, through reasonable design of the balance parameters, that is, designing the number and size of the counterweights and their installation positions on the crank, the sum of the polished rod moment and the walking beam structural moment of the pumping unit can be maximally balanced with the moment of the connecting rod throughout the operation process. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0023] Figure 1 It is the theoretical dynamometer card of the polished rod of the present invention;
[0024] Figure 2 It is the actual dynamometer card of the polished rod of the present invention.
[0025] ICON DESCRIPTION:
[0026] a - Gravity of the polished rod and the sucker rod in the liquid; b - Maximum static load borne by the polished rod; A - Starting position of the polished rod; B - Position when the polished rod moves upward and the rod string extends to the maximum value; C - Position when the polished rod moves upward and continues to run to the extreme value when the rod string extends to the maximum value; D - Position when the polished rod moves downward and the rod string contracts to the maximum value;
[0027] Point X: The convex point on the AB curve of the A - B section; Point Y: The concave point on the CD curve of the C - D section; Point Z: The concave point on the CD curve of the C - D section. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.
[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.
[0030] Beam pumping unit system composition and lifting principle:
[0031] It is a rod pumping system composed of a pumping unit, sucker rods, and a subsurface pump, which is the most traditional and typical artificial lift oil production method.
[0032] The pumping unit mainly consists of a chassis, a support, a beam, a crossbeam, a connecting rod, a crank, a counterweight, a pony head, a hanger, a braking device, a motor, a reducer, and a circuit control device. Among them, the four-link mechanism of the crank, connecting rod, crossbeam, and beam together is called the four-link mechanism of the pumping unit. Through the four-link mechanism, the rotary motion of the crank is transformed into the reciprocating linear motion of the polished rod up and down, so as to achieve the goal of lifting the fluid in the bottom pipe string through the subsurface pump connected by the sucker rods.
[0033] During the oil production lifting process, in order to achieve the energy-saving effect of the beam pumping unit, the state where the moments at both ends of the beam fulcrum of the beam pumping unit are equal is selected as the balance principle.
[0034] During lifting, since the beam of the beam pumping unit reciprocates up and down with the beam fulcrum as the axis, it is necessary to complete the design that the sum of the moments of the front arm of the beam and the sum of the moments of the rear arm of the beam with the beam fulcrum as the axis are equal within one up and down operation cycle of the beam pumping unit, that is, it is necessary to reasonably design the balance parameters related to the front arm and the rear arm of the beam.
[0035] Set the moment M of the front arm of the beam with the beam fulcrum as the axis 前臂 , and the moment M of the rear arm of the beam 后臂 . Then, when the beam pumping unit operates for one week, the equal design of its moment set is
[0036] Among them, M 前臂 == M 光杆 + M 前臂结构 , M 后臂 == M 连杆 + M 后臂结构 .
[0037] We know that the state where the lever is at rest or rotating uniformly around the fulcrum is the balanced state of the lever. When the lever is in the balanced state, the torques at both ends of the fulcrum are equal. At this time, the external force used to rotate around the fulcrum is the smallest and naturally the most energy-efficient.
[0038] Set the torque of the front arm of the walking beam around the fulcrum of the walking beam as M 前臂 , and the torque of the rear arm of the walking beam as M 后臂 . Then, when the beam pumping unit runs one week, the equality of its torque set is designed as:
[0039]
[0040] Because M 前臂 == M 光杆 + M 前臂结构 ; M 后臂 == M 连杆 + M 后臂结构 ;
[0041] That is
[0042] That is to say
[0043] Also
[0044] Among them,
[0045] Because the polished rod torque M 光杆 , M 光杆 = F 光杆 × L 前臂 ;
[0046] Among them, M 光杆 : represents the polished rod torque; F 光杆 : represents the polished rod load; L 前臂 : represents the distance from the polished rod to the fulcrum of the walking beam.
[0047] Theoretically: As shown in the theoretical polished rod indicator diagram in Figure 1 , during the up and down reciprocating lifting operation of the polished rod, when the polished rod moves upward, the load F 光杆 gradually increases from a at point A to b at point B, then stabilizes at b and continues to point C. Then, when the polished rod moves downward, the load F 光杆 gradually decreases from b at point C to a at point D, and then stabilizes at a and continues to point A, forming a closed cycle from 0 - 2π.
[0048] Actually: As shown in Figure 2The actual dynamometer card of the polished rod shown. During the reciprocating lifting operation of the polished rod up and down, since the polished rod drives the piston of the sucker rod pump to move up and down to lift the wellbore fluid through the sucker rod, and there are elastic expansion and contraction, inertia and friction effects during the reciprocating movement of the sucker rod, as well as the influence of pump diameter, pump depth and different fluids, it will cause different expansion and contraction changes of the polished rod and the tubing, and ultimately affect the load F of the polished rod. 光杆 , therefore, within one up and down operation cycle, F of the polished rod is constantly changing, and the magnitude of this change can be read from the actual dynamometer card of the polished rod at the wellhead ( Figure 2 ).
[0049] Therefore, although L 前臂 remains unchanged, F 光杆 and the moment M formed with the beam fulcrum as the axis 光杆 are still constantly changing.
[0050] For this reason, on the closed-loop curve formed by the four key points ABCD on the actual dynamometer card of the polished rod at the wellhead (as Figure 2 shown), that is: the starting point A is the F when the polished rod is moving up and ψ = 0 光杆 , point B is the F when the polished rod is moving up to the point where the rod and tubing stretch to the maximum value 光杆 , point C is the F when the polished rod is moving up to the point where the rod and tubing stretch to the maximum value and continues to run 光杆 , point D is the F when the polished rod is moving down to the point where the rod and tubing contract to the maximum value 光杆 , respectively forming four curve segments AB, BC, CD, and DA.
[0051] Since the actual dynamometer card of the polished rod is a closed-loop curve with ABCD as the four key points, connecting its points continuously with straight lines forms four straight lines A - B, B - C, C - D, and D - A. Any point outside the two-point connection of the closed-loop curve is a convex point, and the point inside is a concave point.
[0052] The determination of the key points is based on the closed-loop curve with ABCD as the key points. The points with the maximum curvature or the minimum radius of curvature on the closed-loop curve are its A point, B point, C point, and D point. The determination of the convex point or concave point is the point at the maximum distance between the four straight lines A - B, B - C, C - D, and D - A and the ABCD curve respectively. If there are multiple maximum points on the four straight lines, there are multiple convex points or concave points.
[0053] In actual production verification, the following balance parameter design method is the most energy-saving:
[0054] When calculating the moment set of the polished rod moment M 光杆 for one up and down operation cycle, take the sum of the moment sets formed by continuously connecting the key points ABCD including the convex and concave points with straight lines during one operation cycle, which is the set of the polished rod moments.
[0055] If there are n1, n2, n3, and n4 linear protrusions or depressions on each of the curve segments AB, BC, CD, and DA respectively, then the A - B segment is divided into n1 + 1 intervals, the B - C segment is divided into n2 + 1 intervals, the C - D segment is divided into n3 + 1 intervals, and the D - A segment is divided into n4 + 1 intervals.
[0056] The polished rod load F is calculated for each interval using the linear median method 光杆 , as the polished rod load F' for that interval 光杆 . Then the polished rod loads F for each interval of the A - B segment 光杆 are respectively F'11, F'21, … F'n1, F'n1 + 1; F'11 = [F(ψ01) + F(ψ11)] / 2;
[0057] F'21 = [F(ψ11) + F(ψ21)] / 2;
[0058] ………;
[0059] F'n1 = [F(ψn1 - 1) + F(ψn1)] / 2;
[0060] F'n1 + 1 = [F(ψn1) + F(ψn1 + 1)] / 2;
[0061] Then the polished rod loads F for each interval of the B - C segment 光杆 are respectively F'12, F'22, … F'n2, F'n2 + 1; F'12 = [F(ψn1 + 1) + F(ψ12)] / 2;
[0062] F'22 = [F(ψ12) + F(ψ22)] / 2;
[0063] ………;
[0064] F'n2 = [F(ψn2 - 1) + F(ψn2)] / 2;
[0065] F'n2 + 1 = [F(ψn2) + F(ψn2 + 1)] / 2;
[0066] Then the polished rod loads F for each interval of the C - D segment 光杆 are respectively F'13, F'23, … F'n3, F'n3 + 1; F'13 = [F(ψn2 + 1) + F(ψ13)] / 2;
[0067] F'23 = [F(ψ13) + F(ψ23)] / 2;
[0068] ………;
[0069] F'n3 = [F(ψn3 - 1) + F(ψn3)] / 2;
[0070] F'n3 + 1 = [F(ψn3) + F(ψn3 + 1)] / 2;
[0071] Then the polished rod loads F for each interval of the D - A section 光杆 , are F'14, F'24, … F'n4, F'n4 + 1 respectively; F'14 = [F(ψn3 + 1) + F(ψ14)] / 2;
[0072] F'24 = [F(ψ14) + F(ψ24)] / 2;
[0073] ………;
[0074] F'n4 = [F(ψn4 - 1) + F(ψn4)] / 2;
[0075] F'n4 + 1 = [F(ψn4) + F(ψn4 + 1)] / 2;
[0076] Since there are n1, n2, n3, n4 linear protrusions or depressions on each of the AB, BC, CD, and DA curve segments respectively, the A - B section is divided into n1 + 1 intervals, the B - C section is divided into n2 + 1 intervals, the C - D section is divided into n3 + 1 intervals, and the D - A section is divided into n4 + 1 intervals.
[0077] Then the set intervals of the A - B section are (11), (21)…(n1), (n1 + 1);
[0078] Among them, the set interval of (11) is ψ01 → ψ11;
[0079] (21) set interval is ψ11 → ψ21;
[0080] ………;
[0081] (n1) set interval is ψn1 - 1 → ψn1;
[0082] (n1 + 1) set interval is ψn1 → ψn1 + 1;
[0083] Then the set intervals of the B - C section are (12), (22)…(n2), (n2 + 1);
[0084] Among them, the set interval of (12) is ψn1 + 1 → ψ12;
[0085] (22) set interval is ψ12 → ψ22;
[0086] ………;
[0087] (n2) set interval is ψn2 - 1 → ψn2;
[0088] (n2 + 1) set interval is ψn2 → ψn2 + 1;
[0089] Then the set intervals of the C-D segments are (13), (23), …, (n3), (n3 + 1);
[0090] Among them, the set interval of (13) is ψn2 + 1 → ψ13;
[0091] The set interval of (23) is ψ13 → ψ23;
[0092] ………;
[0093] The set interval of (n3) is ψn3 - 1 → ψn3;
[0094] The set interval of (n3 + 1) is ψn3 → ψn3 + 1;
[0095] Then the set intervals of the D-A segments are (14), (24), …, (n4), (n4 + 1);
[0096] The set interval of (14) is ψn3 + 1 → ψ14;
[0097] The set interval of (24) is ψ14 → ψ24;
[0098] ………;
[0099] The set interval of (n4) is ψn4 - 1 → ψn4;
[0100] The set interval of (n4 + 1) is ψn4 → ψn4 + 1;
[0101] When calculating the polished rod torque M 光杆 When calculating the torque set value during one up and down run (0 - 2π), take the sum of the torque set values formed by continuously connecting the key points of the ABCD curve including the convex and concave points during its one - week run. That is:
[0102]
[0103] Among them
[0104]
[0105] And
[0106]
[0107] The calculation of the polished rod torque for each of the AB, BC, CD, and DA curve segments can be deduced by analogy to obtain the torque set value for each interval during one up and down cycle (0 - 2π) of the polished rod;
[0108] Then, by accumulating the torque set values for each interval, the sum of the torques during one up and down cycle (0 - 2π) of the polished rod can be obtained.
[0109] Because M结构 = M 前臂结构 -M 后臂结构 ;
[0110] Wherein, M 结构 : represents the moment of the walking beam structure; M 前臂结构 : represents the moment of the front arm structure; M 后臂结构 : represents the moment of the rear arm structure;
[0111] The said M 前臂结构 includes M1 and M2; wherein,
[0112] M1 is the moment of the weight of the walking beam head, M1 == F1 × L1 = m1g × L1;
[0113] F1 is the weight of the walking beam head, L1 is the distance from the center of gravity of the walking beam head to the fulcrum of the walking beam, and m1 is the mass of the walking beam head;
[0114] M2 is the moment of the weight of the front arm of the walking beam, M2 = F2 × L2 = m2g × L2;
[0115] F2 is the weight of the front arm of the walking beam, L2 is the distance from the center of gravity of the front arm of the walking beam to the fulcrum of the walking beam, and m2 is the mass of the front arm of the walking beam;
[0116] The said M 后臂结构 includes M3, M4 and M5; wherein,
[0117] M3 is the moment of the weight of the rear arm of the walking beam, M3 = F3 × L3 = m3g × L3;
[0118] F3 is the weight of the rear arm of the walking beam, L3 is the distance from the center of gravity of the rear arm of the walking beam to the fulcrum of the walking beam, and m3 is the mass of the rear arm of the walking beam;
[0119] M4 is the moment of the weight of the cross beam, M4 = F4 × L4 = m4g × L4;
[0120] F4 is the weight of the cross beam, L4 is the distance from the center of gravity of the cross beam to the fulcrum of the walking beam, and m4 is the mass of the cross beam;
[0121] M5 is the moment of the weight of the two side connecting rods, M5 = F5 × L5 = m5g × L5;
[0122] F5 is the weight of the two side connecting rods, L5 is the distance from the center of gravity of the connecting rod to the fulcrum of the walking beam, and m5 is the mass of the two side connecting rods.
[0123] Therefore, M 结构 = (m1g × L1 + m2g × L2) - (m3g × L3 + m4g × L4 + m5g × L5);
[0124] Therefore,
[0125] Due to the connecting rod moment M 连杆 , M连杆 = F 连杆 × L 后臂 ;
[0126] Wherein, M 连杆 : represents the connecting rod moment; F 连杆 : represents the vertical downward pulling force of the connecting rod; L 后臂 : represents the distance from the top of the connecting rod to the fulcrum of the walking beam;
[0127] According to the principle of moment balance, F 连杆 · L 曲连 = M 曲柄 + M 平衡块 ;
[0128] And M 曲柄 = F6 · L6 = m6g · L6;
[0129] M 平衡块 = F7 · L7 = m7g · L7;
[0130] So F 连杆 = (m6g · L6 + m7g · L7) / L 曲连 ;
[0131] Wherein, F6 is the gravity of the crank, L6 is the distance from the center of gravity of the crank to the crank rotation axis, m6 is the mass of the crank, g is the acceleration due to gravity, F7 is the gravity of the balance weight, L7 is the distance from the center of gravity of the balance weight to the crank rotation axis, m7 is the mass of the balance weight, L 曲连 is the distance from the bottom end of the connecting rod to the crank rotation axis, L 后臂 is the distance from the top of the connecting rod to the fulcrum of the walking beam.
[0132] Therefore, M 连杆 = = [(m6g · L6 + m7g · L7) / L 曲连 × L 后臂 ;
[0133] Therefore,
[0134] For a specific beam pumping unit in production, when the polished rod runs up and down for one week, the set value of the polished rod moment and the set value of the structural moment are fixed values at a certain stage. Only the balance weight parameters involved in the set value of the connecting rod moment can be adjusted. Therefore, the corresponding parameter values can be obtained from the following equations to achieve the best energy-saving effect.
[0135]
[0136] The present invention is applicable not only to conventional beam pumping units, but also to front-mounted, heterophase, and double-beam head beam pumping units.
[0137] Embodiment 1
[0138] Taking a certain beam pumping unit as an example, its basic parameters are as follows:
[0139] Parameter values of a certain type of beam pumping unit
[0140]
[0141]
[0142] In this embodiment, it is necessary to calculate the distance from the center of gravity of the reasonable counterweight to the crank rotation axis according to the known data, that is, parameter L7.
[0143] According to the above principle, it can be known that as Figure 2 shown: Point X on the AB curve of the indicator diagram from A to B is a convex point, there are no convex or concave points on the BC curve of the B-C section, points Y and Z on the CD curve of the C-D section are concave points, and there are no convex or concave points on the DA curve of the D-A section.
[0144] Since there is 1 convex point X on the AB curve, the A-B section is divided into 2 intervals; since there are no convex or concave points on the BC curve, the B-C section remains 1 interval; since there is 1 concave point Y and 1 concave point Z on the CD curve, the C-D section is divided into 3 intervals; since there are no convex or concave points on the DA curve, the D-A section remains 1 interval.
[0145] In this embodiment, when calculating the polished rod torque M 光杆 for the torque set value during one up and down operation, take the sum of the torque set values formed by continuously connecting the convex and concave points during one operation as the set of polished rod torques. The steps are as follows:
[0146] The linear median method is used to calculate the polished rod load F 光杆 in each interval, as the polished rod load F' 光杆 for this interval.
[0147] Then the polished rod loads F 光杆 for the two intervals of the A-B section are respectively F'11 and F'21;
[0148] F'11 = [F(ψ01) + F(ψ11)] / 2;
[0149] F'21 = [F(ψ11) + F(ψ21)] / 2;
[0150] Then the polished rod load F 光杆 for the B-C section interval is F'12;
[0151] F'12 = [F(ψ21) + F(ψ12)] / 2;
[0152] Then the polished rod loads F 光杆 for the three intervals of the C-D section are respectively F'13, F'23, and F'33;
[0153] F'13 = [F(ψ12) + F(ψ13)] / 2;
[0154] F'23 = [F(ψ13) + F(ψ23)] / 2;
[0155] F'33 = [F(ψ23) + F(ψ33)] / 2;
[0156] Then the polished rod load F in the D - A section interval 光杆 , is F'14;
[0157] F'14 = [F(ψ33) + F(ψ14)] / 2;
[0158] The proportion of each interval in one cycle (0 - 2π) of the polished rod moving up and down is used as the set interval of this interval. Here, F(ψ01) is the load at point A of the polished rod, F(ψ11) is the load at point X of the polished rod, F(ψ21) is the load at point B of the polished rod, F(ψ12) is the load at point C of the polished rod, F(ψ13) is the load at point Y of the polished rod, F(ψ23) is the load at point Z of the polished rod, F(ψ33) is the load at point D of the polished rod, and F(ψ14) is the load at point A of the polished rod;
[0159] Then the set interval of the A - X section is ψ01 - ψ11;
[0160] Then the set interval of the X - B section is ψ11 - ψ21;
[0161] Then the set interval of the B - C section is ψ21 - ψ12;
[0162] Then the set interval of the C - Y section is ψ12 - ψ13;
[0163] Then the set interval of the Y - Z section is ψ13 - ψ23;
[0164] Then the set interval of the Z - D section is ψ23 - ψ33;
[0165] Then the set interval of the D - A section is ψ33 - ψ14;
[0166] When calculating the polished rod torque M 光杆 When calculating the set value of the torque during one cycle of moving up and down, take the sum of the set values of the torques formed by continuously connecting the convex and concave points during one cycle, which is the set value of the polished rod torque, that is:
[0167]
[0168] The coordinate values of each point on the actual indicator diagram are as follows
[0169] The coordinate values of each point on the actual indicator diagram (F unit: KN, ψ unit: radian)
[0170]
[0171] Substitute the specific values into the following formula (unit: kilonewton - meter)
[0172]
[0173]
[0174]
[0175]
[0176]
[0177]
[0178]
[0179] After successively calculating the torque set values for each interval during one cycle (0 - 2π) of the polished rod moving up and down, sum the torque set values for each interval, and the sum of the torques for one cycle (0 - 2π) of the polished rod moving up and down can be obtained, that is:
[0180] Since the torque of the walking - beam structure M 结构 , M 结构 == M 前臂结构 - M 后臂结构 ;
[0181] Among them, M 结构 : torque of the walking - beam structure, M 前臂结构 : torque of the front - arm structure, M 后臂结构 : torque of the rear - arm structure. Here, M 前臂结构 = M1 + M2, where: M1 is the torque of the pony - head gravity, M1 == F1×L1 = m1g×L1, symbol: F1 is the gravity of the pony - head, L1 is the distance from the center of gravity of the pony - head to the fulcrum of the walking - beam, m1 is the mass of the pony - head. Among them: M2 is the torque of the front - arm gravity of the walking - beam, M2 = F2×L2 = m2g×L2, symbol: F2 is the gravity of the front - arm of the walking - beam, L2 is the distance from the center of gravity of the front - arm of the walking - beam to the fulcrum of the walking - beam, m2 is the mass of the front - arm of the walking - beam.
[0182] M 后臂结构= M3 + M4 + M5, where: M3 is the gravitational moment of the rear arm of the walking beam, M3 = F3×L3 = m3g×L3, symbols: F3 is the gravity of the rear arm of the walking beam, L3 is the distance from the center of gravity of the rear arm of the walking beam to the fulcrum of the walking beam, m3 is the mass of the rear arm of the walking beam; where: M4 is the gravitational moment of the crossbeam, M4 = F4×L4 = m4g×L4, symbols: F4 is the gravity of the crossbeam, L4 is the distance from the center of gravity of the crossbeam to the fulcrum of the walking beam, m4 is the mass of the crossbeam; where: M5 is the gravitational moment of the two side connecting rods, M5 = F5×L5 = m5g×L5, symbols: F5 is the gravity of the two side connecting rods, L5 is the distance from the center of gravity of the connecting rod to the fulcrum of the walking beam, m5 is the mass of the two side connecting rods.
[0183] Therefore, M 结构 == (m1g×L1 + m2g×L2) - (m3g×L3 + m4g×L4 + m5g×L5) (g = 10N / Kg);
[0184] Substitute the data in the parameter value table into the above formula:
[0185]
[0186] Since the connecting rod moment M 连杆 , M 连杆 == F 连杆 ×L 后臂 ;
[0187] Among them, M 连杆 : connecting rod moment, F 连杆 : vertical downward pulling force of the connecting rod, L 后臂 : distance from the top of the connecting rod to the fulcrum of the walking beam.
[0188] According to the principle of moment balance, F 连杆 ·L 曲连 == M 曲柄 + M 平衡块 ;
[0189] And M 曲柄 == F6·L6 = m6g·L6;
[0190] M 平衡块 == F7·L7 = m7g·L7;
[0191] So F 连杆 == (m6g·L6 + m7g·L7) / L 曲连 ;
[0192] Among them, F6 is the gravity of the crank, L6 is the distance from the center of gravity of the crank to the rotation axis of the crank, m6 is the mass of the crank, g is the acceleration due to gravity, F7 is the gravity of the balance weight, L7 is the distance from the center of gravity of the balance weight to the rotation axis of the crank, m7 is the mass of the balance weight, L 曲连 is the distance from the bottom end of the connecting rod to the rotation axis of the crank, L 后臂It is the distance from the top of the connecting rod to the fulcrum of the walking beam.
[0193] Therefore, M 连杆 == [(m6g·L6 + m7g·L7) / L 曲连 ×L 后臂 ;
[0194] Therefore,
[0195]
[0196] For a specific beam pumping unit, when the polished rod runs one week upward, both the polished rod torque set and the structural torque set are specific fixed values. Only the balance weight parameters involved in the connecting rod torque set can be adjusted. Therefore, the corresponding parameter values can be obtained from the following equations to achieve the best energy-saving effect.
[0197]
[0198] Substitute the above values:
[0199] 639.6π + 67π == 240π + 264πL7;
[0200] So, L7 == 1.77 meters.
[0201] Of course, in this embodiment, only the distance from the center of gravity point of the balance weight to the crank rotation axis is calculated. Those skilled in the art can completely follow the idea of the present invention and make optimal choices for other parameters according to other data given in the actual situation, such as the choice of the size or quantity of the balance weight, etc.
[0202] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.
Claims
1. A design method for the balance parameters of a beam pumping unit, characterized in that, it includes: S1: Obtain the basic parameters of the beam pumping unit, including: the mass of the walking beam head, the distance from the center of gravity of the walking beam head to the fulcrum of the walking beam, the mass of the front arm of the walking beam, the distance from the center of gravity of the front arm of the walking beam to the fulcrum of the walking beam, the mass of the rear arm of the walking beam, the distance from the center of gravity of the rear arm of the walking beam to the fulcrum of the walking beam, the mass of the crossbeam, the distance from the center of gravity of the crossbeam to the fulcrum of the walking beam, the mass of the connecting rod, the distance from the center of gravity of the connecting rod to the fulcrum of the walking beam, the distance from the bottom end of the connecting rod to the crank rotation axis, the distance from the top end of the connecting rod to the fulcrum of the walking beam, the distance from the polished rod to the fulcrum of the walking beam, the mass of the crank, the distance from the center of gravity point of the crank to the crank rotation axis, the mass of the balance weight, the number of balance weights, and take the distance from the center of gravity point of the balance weight to the crank rotation axis as the parameter for adjusting the balance; S2: Measure the actual polished rod dynamometer card of the beam pumping unit, determine the four vertices on the dynamometer card, calculate the polished rod load between the vertices using the median method, and then obtain the polished rod torque M by multiplying the polished rod load by the distance from the polished rod to the beam fulcrum. 光杆 value; S3: Substitute the measured data in S1 and S2 into the formula to obtain the optimal balance parameter value; where M 前臂 represents the moment of the front arm of the walking beam, M 后臂 represents the moment of the rear arm of the walking beam, represents the sum of the moments of the front arm during one up-and-down operation cycle of the beam pumping unit, represents the sum of the moments of the rear arm during one up-and-down operation cycle of the beam pumping unit.
2. The design method for the balance parameters of the beam pumping unit according to claim 1, characterized in that, in S2, determine the four vertices on the indicator diagram at the place with the maximum curvature or the minimum radius of curvature.
3. The design method for the balance parameters of the beam pumping unit according to claim 2, characterized in that, in S2, also compare the curve in the actual indicator diagram of the polished rod with the connection line of the four vertices in the actual indicator diagram, and determine the concave point and the convex point at the place with the maximum distance from the connection line. Among them, the curve of the actual indicator diagram of the polished rod outside the connection line of each two vertices is the convex point, and the one inside is the concave point; use the concave points, convex points and vertices in the actual indicator diagram of the polished rod to divide the actual indicator diagram of the polished rod into several continuous line segments, and calculate the polished rod load of each segment by the median method.
4. The design method for the balance parameters of the beam pumping unit according to claim 1, characterized in that, in S3, the torque of the front arm of the walking beam includes the structural torque of the front arm of the walking beam and the polished rod torque; the torque of the rear arm of the walking beam includes the structural torque of the rear arm of the walking beam and the connecting rod torque.
5. The design method for the balance parameters of the beam pumping unit according to claim 4, characterized in that, the structural torque of the front arm of the walking beam includes the gravity torque of the walking beam head and the gravity torque of the front arm of the walking beam.
6. The design method for the balance parameters of the beam pumping unit according to claim 4, characterized in that, the structural torque of the rear arm of the walking beam includes the gravity torque of the rear arm of the walking beam, the gravity torque of the crossbeam and the gravity torques of the two side connecting rods.
7. The design method for the balance parameters of the beam pumping unit according to claim 4, characterized in that, the connecting rod torque is calculated by the crank torque and the balance weight torque.
8. The design method for the balance parameters of the beam pumping unit according to claim 1, characterized in that, In step S3, the formula is further optimized according to the specific components of the beam pumping unit as