CN103226653A - Method of forecasting suspension center loads of oil pumping unit of directional well segmentally according to pump depth - Google Patents

Abstract

The invention relates to a method of forecasting suspension center loads of an oil pumping unit of a directional well segmentally according to pump depth. The method comprises the steps of (1) selecting a calculation formula of the maximum load and the minimum load, (2) dividing the pump depth into a plurality of segments according to different combination modes of sucker rod strings at different pump depths, conducting linear regression on the actual loads of the segments and the loads calculated by the formula selected in Step (1), and (3) substituting linear regression slopes kmax of the maximum loads of the segments into the formula selected in Step (1) to obtain an optimization formula of the maximum suspension center load of the directional well, substituting linear regression slopes kmin of the minimum loads of the segments into the formula selected in Step (1) to obtain an optimization formula of the minimum suspension center load of the directional well, and calculating the maximum suspension center load and the minimum suspension center load of the directional well with the optimization formulae. The calculation of the suspension center loads is simple and convenient, the results are more accurate, and the relative error of the calculated loads is less than that calculated by an empirical formula.

Description

A kind of method of pressing the dark segmentation prediction of pump orientation well oil pumper polished rod load

Technical field

The present invention relates to the oil-field development field, particularly a kind of method by oil well pump setting depth of pump segmentation prediction orientation well oil pumper polished rod load.

Background technology

The ultimate principle of calculating the method for orientation well polished rod load both at home and abroad is to get a junior unit length to carry out force analysis (seeing accompanying drawing 1) in well, borehole axis is regarded as the circular curve that is not waited by many sections radius-of-curvature to be formed, adjacent two deviational surveys point is one section, consider friction force between transverse pressure, axial tension, rod tube, the bar liquid etc., with the corresponding hole deviation measuring point in oil well pump piston upper surface is starting point, by calculating every infinitesimal section upper end load piecemeal, up to calculating maximum polished rod load or minimum load.This force analysis has been considered the influence to the roofbolt force-bearing situation of hole drift angle and position angle, carry out the integration superposition by whole sucker rod length and calculate polished rod load, but when calculating, must possess deviational survey data accurately, therefore very inconvenient in using at the scene, calculated amount is big, and owing to be subjected to the influence of various factors, its result of calculation is also inaccurate.

Summary of the invention

In order to solve above technical matters, the invention provides a kind of method by the dark segmentation prediction of pump orientation well oil pumper polished rod load, this method calculates easy and the result is more accurate.

The present invention is achieved through the following technical solutions:

A kind of method of pressing the dark segmentation prediction of pump orientation well oil pumper polished rod load comprises the steps:

(1) computing formula of maximum load and minimum load is calculated in selection;

(2) according to the array mode difference of sucker rod string when the different setting depth of pump setting depth of pump is divided into plurality of sections, the load that the formula of choosing in each section real load and (1) calculates is done linear regression, the regression equation coefficient is the slope of the tropic;

(3) with the slope k of each section maximum load linear regression _MaxThe computing formula of the calculating maximum load of choosing in the value substitution step (1) obtains the optimization formula of orientation well maximum polished rod load, with the slope k of each section minimum load linear regression _MinThe computing formula of the calculating minimum load of choosing in the value substitution step (1) obtains the optimization formula of orientation well minimum polished rod load, utilizes and optimizes the minimum and maximum load of formula calculating orientation well suspension point.

In technique scheme, the formula of described calculating maximum load is from 1. $P_{\max 1}=(W_r+W_l^{/})(1+\frac{{\mathrm{sn}}^2}{1790})$ ② $P_{\max 2}=W_l+W_r(1+\frac{{\mathrm{sn}}^2}{1790})$ ③ $P_{\max 3}=(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$ ④ $P_{\max 4}=(W_r+W_l^{/})(1+\frac{\mathrm{sn}}{137})$ The computing formula of the average relative error minimum of middle result of calculation of selecting and real load;

The formula of described calculating minimum load is from 5. $P_{\min 1}=W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790}$ ⑥ $P_{\min 2}=W_r(1-\frac{{\mathrm{sn}}^2}{1790})$ The middle computing formula of selecting result of calculation and real load average relative error minimum;

In the above formula, P _MaxBe maximum polished rod load, P _MinBe minimum polished rod load, W _rBe the sucker rod string load that acts in the oil pumper upstroke on the oil pumper suspension point,

Be the sucker rod string load that acts in the oil pumper down stroke on the oil pumper suspension point, W _lBe the fluid column load that acts on the oil pumper plunger annular cross-sectional area,

Be the fluid column load that acts on the whole sectional area of oil pumper plunger, s is the oil pumper stroke, and n is the oil pumper jig frequency.

In technique scheme, the optimization formula of described orientation well maximum polished rod load is P _{Max optimizes}=k _Max* P _Max, the optimization formula of described orientation well minimum polished rod load is P _{Min optimizes}=k _Min* P _Min

The method of press the dark segmentation prediction of pump orientation well oil pumper polished rod load that present patent application proposes because calculating is easy and the result is more accurate, reduces than traditional formula by the formula assumed (specified) load relative error of the dark segmentation optimization of pump.

Description of drawings

The orientation well sucker rod infinitesimal force analysis that Fig. 1 provides for the embodiment of the invention.

The pump that Fig. 2 provides for the embodiment of the invention is dark＜calculating maximum load and actual maximum load linear regression curve map during 1200m.

The pump that Fig. 3 provides for the embodiment of the invention is dark＜calculating minimum load and actual minimum load linear regression curve map during 1200m.

The pump that Fig. 4 provides for the embodiment of the invention is calculating maximum load and the actual maximum load linear regression curve map when 1200～1400m deeply.

The pump that Fig. 5 provides for the embodiment of the invention is calculating minimum load and the actual minimum load linear regression curve map when 1200～1400m deeply.

The pump that Fig. 6 provides for the embodiment of the invention is calculating maximum load and the actual maximum load linear regression curve map when 1400～1600m deeply.

The pump that Fig. 7 provides for the embodiment of the invention is calculating minimum load and the actual minimum load linear regression curve map when 1400～1600m deeply.

The pump that Fig. 8 provides for the embodiment of the invention is calculating maximum load and the actual maximum load linear regression curve map when 1600～2000m deeply.

The pump that Fig. 9 provides for the embodiment of the invention is calculating minimum load and the actual minimum load linear regression curve map when 1600～2000m deeply.

The pump that Figure 10 provides for the embodiment of the invention is dark 〉=calculating maximum load and actual maximum load linear regression curve map during 2000m.

The pump that Figure 11 provides for the embodiment of the invention is dark 〉=calculating minimum load and actual minimum load linear regression curve map during 2000m.

Embodiment

Below in conjunction with drawings and Examples technical scheme of the present invention is described in detail.

A kind of method of pressing the dark segmentation prediction of pump orientation well oil pumper polished rod load comprises the steps:

(1) chooses long celebrating oil field and thrown orientation well, contain 5 kinds of roofbolt combinations.

(2) average relative error of real load and each formula result of calculation is made comparisons (seeing Table 1), assembly average as can be known, formula is 3. Maximum load of calculating and formula are 5.

The minimum load that calculates and the average relative error minimum of real load.

Each formula relative error contrast table of table 1

Therefore select formula 3.

Be the maximum load computing formula, formula 5. $P_{\min 1}=W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790}$ Be the minimum load computing formula.

(3) foundation by the segmentation of oil well pump setting depth of pump is the roofbolt combination:

①H＜1200m：16mm×100%

②1200≤H＜1400m：16mm×60%+19mm×40%

③1400≤H＜1600m：19mm×12%+16mm×50%+19mm×38%

④1600≤H＜2000m：22mm×12%+19mm×55%+22mm×33%

⑤H≥2000m：22mm×12%+19mm×48%+22mm×40%

In the present embodiment, different deeply according to the oil well pump pump, the roofbolt combination has five groups, therefore divides five sections to calculate polished rod load.In the above roofbolt combination, the rice number is represented the oil well pump setting depth of pump, and millimeter is represented sucker rod bar footpath, and on behalf of this bar, number percent directly account for the number percent of total roofbolt length.

(5) obtain by the dark segmentation polished rod load of pump computing formula

1. when pump dark＜during 1200m (seeing accompanying drawing 2～accompanying drawing 3): the maximum load linear regression slope k that 3. actual maximum load that records and formula calculate _Max=1.06, the minimum load linear regression slope k that 5. actual minimum load that records and formula calculate _Min=0.85.

Maximum polished rod load is optimized formula: $P_{\max }=1.06(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$

Minimum polished rod load is optimized formula: $P_{\min }=0.85(W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790})$

2. when 1200m≤pump dark＜during 1400m (seeing accompanying drawing 4～accompanying drawing 5): the maximum load linear regression slope k that 3. actual maximum load that records and formula calculate _Max=1.06, the minimum load linear regression slope k that 5. actual minimum load that records and formula calculate _Min=0.87.

Maximum polished rod load is optimized formula: $P_{\max }=1.06(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$

Minimum polished rod load is optimized formula: $P_{\min }=0.87(W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790})$

3. when 1400m≤pump dark＜during 1600m (seeing accompanying drawing 6～accompanying drawing 7): the maximum load linear regression slope k that 3. actual maximum load that records and formula calculate _Max=1.05, the minimum load linear regression slope k that 5. actual minimum load that records and formula calculate _Min=0.88.

Maximum polished rod load is optimized formula: $P_{\max }=1.05(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$

Minimum polished rod load is optimized formula: $P_{\min }=0.88(W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790})$

4. when 1600m≤pump dark＜during 2000m (seeing accompanying drawing 8～accompanying drawing 9): the slope k of the maximum load gained that 3. actual maximum load that records and formula calculate _Max=1.03, the slope k of the minimum load gained that 5. actual minimum load that records and formula calculate _Min=0.90.

Maximum polished rod load is optimized formula: $P_{\max }=1.03(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$

Minimum polished rod load is optimized formula: $P_{\min }=0.90(W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790})$

5. when pump dark 〉=during 2000m (seeing accompanying drawing 10～accompanying drawing 11): the maximum load linear regression slope k that 3. actual maximum load that records and formula calculate _Max=1.01, the minimum load linear regression slope k that 5. actual minimum load that records and formula calculate _Min=0.90.

Maximum polished rod load is optimized formula: $P_{\max }=1.01(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$

Minimum polished rod load is optimized formula: $P_{\min }=0.90(W_r^{/}-\frac{W_r{\mathrm{sn}}^2}{1790})$

Method assumed (specified) load relative error by the dark segmentation prediction of oil well pump pump orientation well polished rod load reduces about 3% than experimental formula, particularly when pump dark 〉=2000 meters the time, the relative error of optimizing formula calculating polished rod load has reduced by 5～8% than experimental formula, utilize this formula more accurate prediction polished rod load, can effectively instruct this newly developed area, oil field oil pumper type selecting.In order to guarantee that oil pumper all leaves certain load surplus when normal operation is selected under each situation, the polished rod load and the on-the-spot actual condition that utilize the system of selection of experimental formula to compare the present invention's measurement with routine more mate, avoided reserving the multi-load surplus, make the pump load rate promote 7%, and then improved system effectiveness.

It should be noted last that, above embodiment is only in order to technology implementation scheme that this material is described but not restriction, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (3)

1. a method of pressing the dark segmentation prediction of pump orientation well oil pumper polished rod load is characterized in that: comprise the steps:

(1) computing formula of maximum load and minimum load is calculated in selection;

(2) according to the array mode difference of sucker rod string when the different setting depth of pump setting depth of pump is divided into plurality of sections, the load that the formula of choosing in each section real load and (1) calculates is done linear regression, the regression equation coefficient is the slope of the tropic;

(3) with the slope k of each section maximum load linear regression _MaxThe computing formula of the calculating maximum load of choosing in the value substitution step (1) obtains the optimization formula of orientation well maximum polished rod load; Slope k with the linear regression of each section minimum load _MinThe computing formula of the calculating minimum load of choosing in the value substitution step (1) obtains the optimization formula of orientation well minimum polished rod load, utilizes and optimizes the minimum and maximum load of formula calculating orientation well suspension point.

2. the method for pressing the dark segmentation of pump prediction orientation well oil pumper polished rod load described in claim 1 is characterized in that: the formula of described calculating maximum load is from 1. $P_{\max 1}=(W_r+W_l^{/})(1+\frac{{\mathrm{sn}}^2}{1790})$ ② $P_{\max 2}=W_l+W_r(1+\frac{{\mathrm{sn}}^2}{1790})$ ③ $P_{\max 3}=(W_r+W_l)(1+\frac{{\mathrm{sn}}^2}{1790})$ ④ $P_{\max 4}=(W_r+W_l^{/})(1+\frac{\mathrm{sn}}{137})$ The computing formula of the average relative error minimum of middle result of calculation of selecting and real load;

The formula of described calculating minimum load is from 5.

6. The middle computing formula of selecting result of calculation and real load average relative error minimum;

In the above formula, P _MaxBe maximum polished rod load, P _MinBe minimum polished rod load, W _rBe the sucker rod string load that acts in the oil pumper upstroke on the oil pumper suspension point,

Be the sucker rod string load that acts in the oil pumper down stroke on the oil pumper suspension point, W _lBe the fluid column load that acts on the oil pumper plunger annular cross-sectional area,

Be the fluid column load that acts on the whole sectional area of oil pumper plunger, s is the oil pumper stroke, and n is the oil pumper jig frequency.

3. the method for pressing the dark segmentation of pump prediction orientation well oil pumper polished rod load described in claim 1, it is characterized in that: the optimization formula of described orientation well maximum polished rod load is P _{Max optimizes}=k _Max* P _Max, the optimization formula of described orientation well minimum polished rod load is P _{Min optimizes}=k _Min* P _Min

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