SU953199A1 - Method of measuring liquid flow rate in well - Google Patents

Description

cross-section of the well. This affects, in particular, when it is moved upwards by speeds exceeding the flow velocity: the flow sections are narrowed around the cable. The flow rate in this case changes as long as the well cross-section no longer affects the flow rate. To determine the cross section taken by the logging cable of the stream, not only special cable calibrations and the state of its surface are necessary, but also knowledge of the total relative speed of cable and fluid movement (the latter is the magnitude of the target. The velocity of the flow is not determined either by each upward velocity corresponds to its own cross section of the flow (unknown).

Variations in the three-way descent rate method allow us to obtain a system of three equations for determining the flow rate, but with great uncertainty, since the flow meter is not taken into account.

A disadvantage of the known method is also the duration of the measurement cycle during which the conditions in the well must be stable and the efficiency of the impeller of the flow meter must be maintained. When preparing the well for flow measurement, it is washed, the solution is replaced with water. In this state, the well is unstable, the walls are weak, the saline streaks dissolve, and the walls fall off. Flow measurement is therefore required to be carried out as quickly as possible in order to prevent the possibility of complications.

The purpose of the invention is to reduce the time and increase the accuracy of determination by taking into account the influence of the flow rate of the flow meter on the plot of flow rates in the cross section of the well.

The goal is achieved by the fact that according to the method, when the flow meter is lowered, the speed of the fluid in the measuring channel of the flow meter and the speed of movement of the flow meter are recorded simultaneously and the flow rate is determined using the following formula

O (VHP - V-Vnp). Q - fluid flow in the well, cm Vc;

V is the velocity of the fluid in the flow meter channel.

cm / s;

- 60 descent rate

ra, cm / s; coefficient numerically equal to the ratio of the velocity of the fluid in the measuring channel of the flow meter 65

to the speed of its descent, in a stationary liquid; channel area

flow meter, cm; Kj is a coefficient numerically equal to the ratio of fluid flow in the wellbore to the fluid flow in the measuring channel of the flow meter. The essence of the method is as follows.

To reduce the time spent in the well-washed state, cross-section measurements are made on the wellbore prior to preparing the well for flow measurement. This can be done either with cavern gauges or cross sections with open hole wells. For well cased wells, with a known cross section, the task is simplified. The accuracy of the measurement results of the flow meter depends on the accuracy of determining the cross sections.

The well preparation for flow measurement is carried out in accordance with the Interim Guidelines for Hydro-Logging Work using the Flow Measurement Method (Ed. Ural Geol. Up. Sverdlovs 1966) ,.

The measurements by the method are carried out by a pre-calibrated flow meter, its uniform one-time movement on the wireline down the wellbore.

The flow meter is calibrated at a special calibration stand or under conditions of a self-flowing well whose cross-section is known, and the flow rate is measured. The results of the calibration are: determining the ratio of the amount of fluid passing through the cross-section of the well to the amount of fluid passing through the well section flow meter window K. It is carried out} on a calibration stand for different diameters and flow rates; Establishing the dependence of the well cross section on the ratio of the signal increment from the draw speed to the flow rate of the flow meter. It is produced in a well that has a known flow rate (or zero flow) and no less than three known cross sections. The results of the calibration are recorded by finding the value of the standard signal in comparison with the signals from the sensors. Standard signals are further used to set the scales of the measurement register 1.

For the implementation of the method, any type of flow meter can be used that gives information about the flow rate: spinner, induction, pressure drop, etc. The signal produced by the sensor in the flowmeter moving along the barrel enters the logging station, which can be any, for example, AEKS, AKS-L-7, OKS, etc. The cable speed sensor in the logging station has a non-linear characteristic (it works on the dial gauge). Therefore, in order to maintain the record scale at any speeds, it is necessary to install an additional linear sensor — a tachometer motor, kinematically connected with the corresponding gear from the gear wheel — the receiver of the depth gauge of the logging station. The flow velocity signal of the flow meter enters the logger of the logging station from the tachometer sensor of the displacement velocity of the flow meter, placed at the wellhead or in the depth of the logging station panel, and kinematically connected with the wireline logging cable. In preparing the recording equipment for operation at the well under study, the scale of recording the signal from the flow meter W and scaling the signal from the span speed sensor V are obtained according to the standard signals obtained when calibrating. Next, measurements are made uniformly. (Without jerks ) move the flow meter from the mouth to the bottom of the well and record the signals W to V simultaneously synchronously on one chart tape. Speed is not regurgitated downstream of the flow meter when recording signals of 1000-1200 m / h (such speed is optimal for the operation of the well station). After measurements are taken on the descent, the well is extracted to the surface. Work on the well is completed.

The resulting diagram is processed. Calculation of fluid flow Q is produced by a special formula

Q (W - V. m - Krr) m K, de Q - flow rate, cm / s; W - signal from the flow meter on the diagram, mm;

V-signal speed

flow meter on the chart, mm;

VI is the coefficient of consistency in the diagrams;

K is a coefficient numerically equal to the ratio of the velocity of the fluid in the measuring channel of the flow meter.

to the speed of his descent; wi - record scale factor;

K. (- coefficient, numerically equal to the ratio of fluid flow in the wellbore to

The method of determining the flow rate of the fluid in the pump based on determining the relative speeds of movement of the flow meter and the flow of the liquid, characterized in that, in order to reduce time and increase the accuracy of determination by taking into account the influence of the speed of movement of the flow meter on the distribution of flow rates in the cross section of the well,

when lowering the flow meter, synchronous recording of the velocity of the fluid in the measuring channel of the flow meter and the velocity of the flow meter and determining the flow rate

fluid according to the following formula

Q P pr where Q. - fluid flow in the well, cm FH;

Claims (3)

/, p is the velocity of the fluid in the flow meter channel, cm / s; flow rate in the measuring channel of the flow meter. The reduced formula is expressed in terms of physical quantities as follows. Q "V - Knp-v p). It is convenient to use flowmeter sensors and drawing speeds with the linear characteristics of their work. However, the latter is not necessary. With non-linear characteristics of the sensors, the coefficient of And scale varies within the measurement process. This also changes the scale of the MD record. To use the above formula, it is necessary to pre-linearize the measurement results from both sensors. The advantages of the proposed method, compared with limestone, are that it is possible to perform continuous measurement along the wellbore, prompt analysis and assessment of the locations of inflows and removals along the wellbore directly on the well. The method eliminates the possibility of skipping intervals of interest, recording the diagrams using an objective automatic documentation of the results. rhenium. The proposed method has the ability to accurately align the cavernogram and flow log, the capturing takes into account the signal gain from the pit depending on the change in the well section (i.e., the diaphragm effect of the flow meter). The method also reduces the measurement time at the well by five to six times. The formula of the invention; c 7 9531998 the rate of descent of the flow rate in the wellbore to pa, cm / s; the flow rate of the fluid in the coefficient of measurement / the numerically equal channel of the flow meter; the supply of fluid in the measured-sources of information, the meter, channel of the flow meter5 taken into account in the examination to the speed of its descent; in 1. US Patent 3,905,226, Class 73-155, fixed fluid; published. 1975. cross-channel area 2. US Patent 3,954,006, class 73-166, course meter, Public. 1976. coefficient, numerically equal-10 3. French Patent 2238836, which is related to liquid-class flow rate. E 21 B 47/00, 1975.