RU49102U1 - DEVICE FOR OPTIMIZATION OF OPERATION OF OIL WELL WITH SIMULTANEOUS MEASUREMENT OF ITS DEBIT - Google Patents

Abstract

The inventive utility model relates to the oil and gas industry and, in particular, to the technique of oil production in fountain, compressor and other mechanized well wells with a high gas factor of produced products. A device for optimizing the operation of an oil well with simultaneous measurement of its flow rate is disclosed, comprising a shut-off element mounted on a flow line, in front of which a first pressure sensor is installed, and a second pressure sensor placed on the annulus of the well, both sensors being connected to a control unit whose output is connected with the actuator of the locking element. What is new is that the outlet of the pipeline is connected to the annulus by a gas pipeline equipped with a second locking element with its own actuator, the input of which is connected to the control unit, each of the locking elements being made in the form of a valve with an adjustable flow rate. The utility model includes 4 dependent claims, 5 figures.

Description

The utility model relates to the oil and gas industry and, in particular, to the technique of oil production in fountain, compressor and wells operated by other mechanized methods with a high gas factor of the produced products.

A device for oil production is known, comprising a shut-off element located on the inlet oil pipeline of the well, a pressure sensor installed at its inlet, and a second pressure transducer placed on the well annulus, connected through the control unit to the shut-off element and having the ability to open the shut-off element when raising at least , one of the measured pressures to the corresponding upper limit value and closing when lowering at least one of the measured pressures to the corresponding lower limit o values ensuring the maintenance of the optimum bottomhole pressure for maximum well production and oil recovery (RU 2165517, class E 21 V 43/00, E 21 V 43/12, 2001).

The device has the following disadvantages, namely: the device optimizes the bottomhole pressure of the well in a relatively wide range of its maximum permissible values, but does not solve the problem of maintaining the optimal bottomhole pressure, which ensures the maximum flow rate of the well, and its measurement. So, for example, when the wellhead pressure increases significantly above the upper limit value, the bottomhole pressure rises accordingly, the depression and fluid inflow into the bottomhole decrease, the production rate decreases and the well is stimulated to switch to a periodic operating mode. The device is advisable to use only for low-production wells operating in periodic operation, which sharply limits its scope.

In addition, to select the optimal mode of operation of the well, it is necessary to constantly conduct well surveys, build up the degassing curves, determine the dependence of flow rate on bottomhole pressure, bottomhole pressure on wellhead and annular pressures. Given the complexity, the complexity of these works and their frequency, as well as a relatively wide range of determined optimal bottomhole pressure, the reliability of its maintenance using a known device

is a technically challenging task, bearing in mind that the parameters of the "formation - bottomhole - well lift" system can change quite quickly, and the device does not provide operational data on the current flow rate of the well and its dynamics.

The basis of this technical solution is the task of creating a universal device for optimizing the operation of an oil well with simultaneous measurement of its flow rate, free from the above disadvantages of the prototype by providing regulation and stabilization of the set value of wellhead pressure, regulation of annular pressure while measuring the flow rate of the well in real time for wells operating both in continuous and periodic operation, both fountain and compressor both high and low flow rates, as well as the ability to quickly determine the optimal bottomhole pressure when changing the parameters of the oil reservoir and lift without a series of laborious studies to select the mode of operation of the well.

The solution of the problem in a device for optimizing the operation of an oil well with a simultaneous measurement of its flow rate, containing a shut-off element installed on the flow oil pipeline, in front of which a first pressure sensor is installed, and a second pressure sensor placed on the annulus of the well, while both sensors are connected to the control unit, the output of which is connected to the actuator of the shut-off element, is achieved by the fact that the output of the oil pipeline is connected to the annulus by a gas pipeline equipped with a second shut-off element with its own m an actuator which is connected to the control unit input, wherein each of the locking bodies is designed as a valve with an adjustable bandwidth.

It is advantageous to ensure the temperature stability of the first shut-off element with its actuator located in a thermostatic measuring chamber equipped with means for measuring its own temperature, fluid temperature and differential pressure of the fluid on the valve, and connect all measuring instruments to the control unit.

It is advisable to provide a linear control characteristic of the valve of the first locking element in the form of an electromechanical measuring reversing mechanism equipped with a needle-seat throttle pair, in which the linear movement of the needle is proportional to the area of the valve passage area.

It is useful to ensure the temperature stability of the second locking element with its actuator in a thermostatic measuring chamber equipped with means for measuring its own temperature and gas pressure in the annulus, while all measuring means are connected to the control unit.

It is also advisable to provide a linear characteristic of regulation of the valve of the second locking element in the form of an electromechanical reversing mechanism equipped with a needle-seat throttle pair.

Figure 1 presents the structural diagram of the inventive device. Figure 2 shows the structural diagram of the control unit based on a microprocessor controller.

Figure 3 shows the nature of the change in the wellhead and annular pressures during operation of the inventive device.

Figure 4 shows the comparative results of measuring the flow rate of the well.

Figure 5 shows the comparative results of measuring the flow rate of the well at different operating modes of the device.

The device for oil production shown in FIG. 1 comprises a tubing 1 of an oil producing well 2, the outlet of which is connected to an inlet thermostat 3, inside of which there is a fragment of an oil pipeline 4 with a shut-off member 5 mounted on it and its electric drive 6. The electric drive 6 is mechanically connected to the locking body 5 and the sensor of the passage area 7. The pressure sensors 8 and 9, temperature 11 and the area of the passage section 7 are connected by their measuring outputs to the measuring inputs of the control unit 12, and the control the cleaning input of the electric actuator 6 and the heating element of the thermostat 22 are connected to the control outputs of the control unit 12. The output of the annular space of the well 2 is connected to the input thermostat 13, inside of which there is a fragment of the gas pipeline 14 with a shut-off member 15 mounted on it with an electric actuator 16 and a pressure sensor 17, and also a temperature sensor 18 and a heating element 21 of the thermostat, while the actuator 16 is mechanically connected to the shut-off member 15, the pressure sensor 17 and the temperature sensor 18 with its measuring outputs with are connected to the measuring inputs of the control unit 12, and the input of the electric drive 16 and the heating element of the thermostat 21 are connected to the control outputs of the control unit 12. The output of the thermostat 13 through the gas pipeline 14 and the check valve 19 is connected to the output of the oil pipeline (oil and gas collection) 20. The temperature regime of thermostats 3 and 13 provided by heating elements

22 and 21, respectively.

Presented in figure 2, the control unit 12 consists of a microprocessor 23, read-only memory (ROM) 24, random access memory (RAM) 25, input-output device 26, analog-to-digital converter (ADC) 27, digital-to-analog converter (DAC) ) 28, output keys 32, interconnected via a system bus 29. A keyboard 30 and an indicator 31 are also connected to the input / output device.

Figure 3 shows the curves of the wellhead and annular pressures of a compressor well operated by a submersible electric centrifugal pump on the mode of its regulation, showing how the wellhead pressure changes when the well operates without its stabilization - curve 33 and during stabilization using the inventive device - curve 34 , and how the pressure in the annulus changes - curve 35 and at the outlet of the first shut-off element (in the oil and gas gathering) - curve 36.

The curves of parallel comparative measurements of the well flow rate shown in Fig. 4 by a group metering device of the "Sputnik - M" (GZU) type - curve 37 and the inventive device (ACS) - curve 38, show how the results of periodic "point" measurements differ by a standard measuring instrument and continuous in real time - the claimed device.

The curves of parallel comparative measurements of the well production rate shown in Fig. 5 by a group metering device of the "Sputnik-M" type — curve 39 and the inventive device — curve 40, show how the measurement results differ in unstabilized wellhead pressure — time section AB and in stabilization of wellhead pressure by the claimed device is a temporary plot BC.

It is known that the gas-oil mixture entering the bottom of the well, even with a significant decrease in pressure (0.30 ... 0.35 of the saturation pressure), remains finely dispersed with the gas phase evenly distributed over the stream and no gas caverns are formed in the interscapular channels of the centrifugal pump speed spectrum [see Bogdanov A.A., Rozantsev V.R., Kholodnyak A.Yu. Selection of submersible centrifugal electric pumps for oil wells of the Devonian fields of Tataria, Bashkiria and Ukhta. M. VNIIOENG, 1972]. The continuous operation of the centrifugal pump allows us to assume that the pumping conditions in the compressor well are similar

operating conditions of the fountain lift [see Briskman A.A., Kez A.N. Work submersible centrifugal pumps on gas-liquid mixtures. -Tr. VNII, issue. 51, 1974]. Thus, in fountain and compressor wells, the fluid entering the wellhead, provided that the wellhead pressure is kept constant, can be taken as a conditional homogeneous compressible fluid with a constant density and its flow rate (flow rate) can be measured, and then, using the known values of water cut and gas factor, determine by calculation flow rate of its components - oil, water and gas. At the same time, the values of water cut and gas factor can be considered constant and periodically adjusted according to the data of the field geological service, and the length of the period between adjustments is determined empirically.

These premises are used to measure the flow rate of the inventive device, which operates as follows. In the initial position, the shutoff control valves 5 and 15 are closed. The control unit 12 receives data on the values of the following parameters: annular pressure - from the sensor 17, temperature in the thermostat 13 - from the sensor 18, wellhead pressure - from the sensor 8, the temperature at the inlet of the shutoff-control valve 5 - from the sensor 10, pressure on it the outlet in the oil gathering 20 - from the sensor 9, the flow area of the shutoff-control valve 5 (the position of its needle) - from the sensor 7 and the temperature in the thermostat 3 - from the sensor 11. If the pressure in the oil gathering 20 does not exceed wellhead and annular, control unit 12 gives a signal through electric d 16 to slightly open the valve 15, which begins to bleed annular gas until the specified annular pressure reaches the set value, after which the control unit 12 switches to its regulation mode. At the same time, a signal is supplied to the actuator 6 and the valve 5 smoothly ajar, through which the well products begin to flow into the oil and gas gathering 20, while the wellhead pressure begins to gradually decrease to a limit value specified by the control program (setpoint) of the control unit 12, after which the control unit 12 switches to its regulation by stabilization of the set value. At the same time, according to the data of temperature sensors 11 and 18, the control unit 12 supports the temperature regimes of thermostats 3 and 13 specified by the relevant settings. After stabilization of the wellhead pressure, a well’s flow rate is measured using fluid measuring device Q, oil separator or sampling device Q ′, oil Q′n, water Q′v and gas Q′g. The received data on the measured flow rates are entered

to the control unit 12, according to the pressure sensors 8 and 9, it determines the pressure drop ΔР on the throttle pair of the valve seat-needle 5, sensor 7 - the relative height of the position of the needle A in the seat of the throttle pair and calculates the flow rate of the conditional fluid according to the formula

Where

Q′uz - the rate of conditional fluid,

Q′n, Q′v, Q′g - flow rates of oil, water and gas, measured by a measuring tool,

P is the pressure drop across the throttling pair, equal to the pressure difference before and after it,

Ru - wellhead pressure,

Pa is atmospheric pressure,

Kv max - maximum flow coefficient of the throttling pair, depending on its conditional passage,

A is the relative height of the position of the needle in the saddle of the throttling pair, varying from 0 to 1,

pH is the density of oil,

Rv is the density of water,

rg is the gas density under normal conditions, after which the control unit 12 switches to continuous determination by the current position of the needle, and the pressure drop across the throttle pair of the current flow rate of the conditional liquid, oil, water and gas in real time using the formulas

Qн = Q off × K1,

Qin = Qin × K2,

Qg = Qzh × K3, where

Quzh - flow rate of the conditional fluid in the current measurement in real time,

Q ′ is the fluid flow rate (oil plus water), measured by a measuring means,

Qн, Qв, Qг - flow rates of oil, water and gas, respectively, with the current measurement in real time,

K1, K2, K3 are the coefficients of the proportion of oil, water and gas in the produced fluid measured by the measuring tool, while the ratio of the flow rate measured by the measuring tool to the flow rate of the conditional fluid is considered constant and periodically adjusted taking into account the actual timing of changes in the current water cut values and gas content of well products.

The value of the fluid temperature at the inlet of the shut-off element 5, measured by a temperature sensor 10, can be used to quickly select the setpoint of the wellhead, and hence bottomhole pressure, based on the condition that the maximum production rate possible at the current moment of the well corresponds to the maximum production temperature. The choice of the wellhead (bottomhole) pressure setting is made by sequentially setting the wellhead pressures in increments of, for example, 10% of the range of its possible limit values and with exposure at each step until the pressure and temperature of the fluid stabilize at the wellhead. The wellhead pressure at which the fluid temperature will be maximum corresponds to the bottomhole pressure at which the well production will be maximum.

In the future, the ratio Q ′ / Q′oug is periodically adjusted according to the results of measurements of the flow rate with a measuring tool, the duration of the period is determined empirically.

The above initial data are embedded in the algorithm for determining well production in the software of the controller of the control unit.

The following is an example of using the inventive device for real wells.

Example.

The operation of the claimed device is experimentally verified at fountain and compressor wells of two bushes of the Yuzhno-Tarasovskoye field 000 "Geoilbent", Yamal-Nenets Autonomous Okrug. Tyumen region

Bush No. 101-13 wells, of which 4 are fountain and 9 are compressor.

Bush No. 102-12 wells, all compressor.

The reservoir pressure is from 20.1 to 33.0 MPa.

Downhole pressure - from 7.1 to 20.9 MPa.

Fluid flow rates from 13 to 443 m ³ / day.

Oil production by the fund - ESP - 85%, fountain - 15%.

Gas factor - up to 260 m ³ / t.

Water cut - from 1 to 91%.

The range of wellhead (buffer) pressures is from 1.0 to 3.0 MPa.

The range of annular pressures is from 0.9 to 10.2 MPa.

At all wells of clusters 101, 102, equipment was installed for a complex of technical means of an automated process control system for oil production, which implements the inventive device and includes:

modules-thermostats with gas-liquid highways (pipelines) of high pressure from the complex SIANT 10 20.00.00 (Russia);

shut-off and regulating valves ЗРК-25 (Russia);

explosion-proof electric drive EPR 8/50 (Russia);

pressure sensors type PT-ZM (Russia);

temperature sensors type TSMU 9418 (Russia);

cluster automation unit (control unit) is implemented on the basis of an RTU-188MX Fastwel type controller (Russia);

a radio channel unit with an antenna device based on the Nevod radio station (Russia).

Centralized bushes management was carried out by a workshop control room, the equipment of which includes a visualization and data server (personal computer with uninterruptible power supply), a radio channel unit with an antenna device based on the Nevod radio station.

For each well, the optimal values of the wellhead and annular pressure settings were chosen, after which they were put into operation under the control of an automatic process control system and tested for flow rate measurement using a standard measuring tool - a group metering unit for the flow rate of the Sputnik-M GZU. Further work of the wells was carried out in accordance with the control algorithm specified by the program.

Figure 3 shows the curves of the wellhead and annular pressures of one of the compressor wells operated by a submersible electric centrifugal pump, from the mode of its regulation, showing how the wellhead pressure changes when the well operates without its stabilization - curve 33 and during stabilization using the inventive device - curve 34,

and how the pressure in the annulus changes - curve 35 and at the outlet of the first shut-off element (in the oil and gas gathering) - curve 36.

For this well, the wellhead pressure setpoint was 1.35 MPa, annular pressure was 1.05 MPa, oil gathering pressure was 0.8 MPa, wellhead pressure change during ESP operation in the well with the stabilization device turned off ranged from 0.5 to 1 , 7 MPa, during operation of the inventive device - (1.35 ± 0.05) MPa. The annular pressure during operation of the inventive device was maintained within (1.05 ± 0.05) MPa.

As a result of the transfer of two bushes for operation by the claimed device, the production volume increased by 10-15%.

The performance of the inventive device in terms of technological measurement of flow rate can be estimated from the data of comparative measurements on the same well, which are shown in figure 4. Determination of the flow rate of the inventive device is provided continuously in real time with an accuracy identical to the accuracy of the satellite "Sputnik-M".

In addition to the above, stabilization of wellhead pressure for compressor wells (see figure 3) allows us to consider it very likely to increase the service life of the ESP and its overhaul period (MCI).

Thus, the inventive device allows you to expand the scope and operational capabilities of the device to optimize the operation of an oil well while measuring its production rate, increase well productivity, oil recovery, provide an increase in the level of automation of the oil production process, minimize work on the study of wells to select the mode of operation and reduce operating costs.

Claims (5)

1. A device for optimizing the operation of an oil well with simultaneous measurement of its flow rate, comprising a shut-off element installed on the flow line, in front of which a first pressure sensor is installed, and a second pressure sensor placed on the annulus of the well, both sensors being connected to a control unit, the output of which connected to the actuator of the locking member, characterized in that the outlet of the oil pipe is connected to the annulus by a gas pipeline equipped with a second locking member with its actuator m, the input of which is connected to the control unit, while each of the locking elements is made in the form of a valve with adjustable throughput. 2. The device according to claim 1, characterized in that the first locking element with its actuator is located in a thermostatic measuring chamber, equipped with means for measuring its own temperature, fluid temperature and differential pressure of the fluid on the valve, while all measuring means are connected to the control unit. 3. The device according to claim 1, characterized in that the valve of the first locking member is made in the form of an electromechanical measuring reversing mechanism, equipped with a needle-seat throttle pair, in which the linear movement of the needle is proportional to the area of the valve passage section. 4. The device according to claim 1, characterized in that the second locking element with its actuator is located in a thermostatic measuring chamber equipped with means for measuring its own temperature and gas pressure in the annulus, while all measuring means are connected to the control unit. 5. The device according to claim 1, characterized in that the valve of the second locking member is made in the form of an electromechanical reversing mechanism equipped with a needle-seat throttle pair.