SU747990A1 - Method of measuring oil well productivity - Google Patents

Description

The invention relates to oil and gas jets, in particular to methods for measuring the performance of oil wells.

There is a known method for measuring well flow time in which time intervals are selected according to a flexible program based on a comparison of the transit time of a fixed amount of fluid in the reference measurement stage with setting the reference time, and in the main measurement stage, the capacity is determined by the measured volume of fluid at the control stage 1.

The disadvantage of this method is that it does not provide reliability with a minimum sample of the amount of data, since the duration of the measurement with this method is set depending on the well productivity and not on the scatter of its current values.

This leads to the fact that the measurement result may be unreliable due to the inconsistency of the volume of selected data with the required, which is determined by the nature of the scattering.

measured values, i.e. type of distribution.

A known method for measuring the flow rate of an oil well fluid is that it measures the average values of the current productivity during a given set time and determines the integral productivity. 2.

ten

In this method, the number of portions of a liquid is measured while simultaneously measuring the duration of the measurement and measured during the measurement with simultaneous recording of the number of portions of the liquid.

The disadvantage of this method is that it does not provide credibility with a minimum sample of the amount of data, since the duration of the measurement in this method is set depending on the productivity of the wells.

The aim of the invention is to increase accuracy and reduce time.

25 measurements of flow rates in the entire range and with pulsating flows.

This goal is achieved by the fact that the integral performance value is determined during the measurement process at successive discrete time intervals and ends the measurement process at. Sole Bodeness of the Condition: j.

. , -.- --os e,

S 3 (edt

where t -... current time; ..

n (the value of the current productivity,) 1.,.,., t is the adaptively set times, m measurements, s

J — integral integralness, kg;

: 6-given measure of the accuracy of determining the average value

performance.

The essence of the method is as follows. - .. In the process of measuring the performance of an oil well, the measurement system gives the current values of U, expressed in units of flow, through

intervals, time,. . .

The integral value of productivity can be expressed graphically as the area of a flat figure, limited by the axes of a rectangular system root, the abscissa axis of which is time, and the ordinate axis is the value of productivity, a line connecting adjacent values of productivity, and a line connecting the last received performance value with the abscissa axis (see fig.) The following information is as follows.

Upon receipt of each new value of the current, produce LUKO1 | and the time interval between adjacent measurements utj perform the following operations:, .-- -:

1) determining the average productivity value by the formula.

.

lj.; ..-.,.:. 4, f ,, ...,.-..... ".--

 L-13

where n is the number of the last received values of y and &t; --- - 2.) determination of the center of gravity of a flat figure representing the integral performance of the well and the expiring time interval t - S itj, which include the following operations:

a) the transformation of a flat figure representing the integral production, consisting in replacing the rectangles representing the ral productivity in the interval between adjacent measurements (.-3,} or) with lumped values equal to rip values of these products, but located in the middle corresponding Intervalbw;

b) calculate the moments of the left D and the right D c, relative to the points on the time axis corresponding to the moments

performance measurement by the formulas ...

; v | ,.

Where is the sequence number of a point; . At- uij j.

r -F-Li- For example, for the integral production of a well, displayed on FIG. If when i 4, p 7.

,

 -.

. E -, -

Where

.

-, n - 5. „. J. bb

e

 LB - (itEVi about 44- e- i

c) determination of the difference D.

dd

. . Calculating D ,. D2.i and their differences

4D is made for each point, shifted to the right along the rsi; time, on the second from the second, until the first hundred years are negative (the point at which this happens will be assigned the number L + 1). . -

0 All of the above operations are repeated upon receipt of each new value of cr, j, until then. The condition C E dz will be raised. Upon the fulfillment of this condition, the calculation terms are preset, and the obtained values of the average current performance are given. tag, its integral value and continuity of measurement. The system switches the measurement of the next well ..,.

To implement the method on a measuring group installation, one dimension is measured and calculated:; current Measurement duration tj., from the beginning of the bill; current (instantaneous) performance.: 3 (t) at time intervals tj. tj;

t - integral performance over time

at time intervals tnAt ,, -;

tj, -JlKOc3t- is an integral integral to the function of the producer-, but it is. and the measurement time tn (t) -t.-dt; -D (t) - - auxiliary integral function manufacturer. tft .v-fei.,

tn j u (t) dt o

- difference 0.5 t;

Claims (2)

- compares the obtained value of € s. given 339; . - average performance value P T net) - dt. Thus, the average value of the current performance and the integral value are measured for an adaptively chosen time at successive discrete time intervals. A block diagram of the system for the implementation of the method is shown in FIG. 2. It is indicated in the diagram; 1 — KONpviyTa- tor, 2 arithmetic mean arithmetic unit, 3 — control unit 4 — unit for calculating the relative abscissa of the center of gravity of the information field, 5 — comparing device, B — scale of standard values of the abertions for the center of gravity of the information field. The system works as follows. The parameters under study are determined with the help of appropriate measuring devices, signals from these devices, in order of priority, which are set by means of the control unit 3, through the switch 1 are fed to the units calculating the arithmetic average 2i. relative abscissa of the center of the tin of the information field 4, Depending on the nature of the measured process, the determination of these characteristics is carried out either continuously or discretely. The difference between the calculated value of the relative abscissa of the center of gravity of the information field (Tt ,, and a value of 0.5b 0.5 -efts) in the measurement process is matched with a given control unit with 3 values of this difference, E-3, 0 (0.5 - cfUvj ), corresponding to the parameter under study, the permissible deviation of the abcissa on the scale of the standard deviation values present in block 6 .. The measurement process is carried out as long as, a (E. (up to the value of the permissible error), With a correlation). this dependence by means of the comparison device 5 gives a signal the control unit 3, which gives permission to block 2 to issue the last calculated value of the arithmetic average of the measured parameter, and gives the block a command to connect the next object to the system.The cycle ends after measuring all the objects connected to the system. wells with pulsating fluid flow by measuring the average performance values for an adaptively set time and determining the integral performance, different So that, in order to increase the accuracy and reduce the measurement time, the integral performance value is determined in the measurement process at consecutive discrete time intervals and ends the measurement process if the following condition is met; I D (-fe) -tdt -tn I 3tt) a-b about where t is the current time; D (t) is the value of current productivity, adaptively set measurement time, s; integral production-. ° weight, kg; - a given measure of the accuracy of determining the average value of productivity. Sources of information taken into account in the examination 1, USSR Copyright Certificate No. 439598, 101, E 21 B 47/10, 1971. 2. USSR author's certificate number 435349, cl. E 21 B 47/10, 1971 (prototype), 747990