RU2588234C1 - Method for cluster release and utilisation of produced water - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry and can be used for cluster release and utilisation of produced water at oil deposits late stage of development. Intake capacity of injection well is measured according to method. Product is supplied to one or more producing wells in well or bore hole for initial water separator. Crude oil and gas amount is measured, as well as water content of crude oil, oil density and water supplied to well or bore hole for initial water separator. Well production is divided into partially dehydrated oil, gas and water. Partially dehydrated oil and gas are directed into collection header. Discarded water is fed into injection well. Compatibility of discarded water with formation water is determined. At compatibility of water injection well is equipped with device for creation of water pressure, sufficient for water injection into bed, made with possibility of changing supply and including minimum feed. Compliance of quality of discarded water with geological formation conditions is determined. If quality of discarded water is unsatisfactory, said water is fed into collection header. Otherwise discarded water its directed to injector. Amount of discarded water supplied to injection well is measured. Then, with selected constant or variable pitch, supply of device is increased for creation of water pressure. Increased water supply is performed until discarded water quality meets geological formation conditions. When from well or bore hole for preliminary water discharge partially dehydrated crude oil with gas is fed into a collecting header, then at the inlet to well or bore hole pressure is increased coming well product at least by value of pressure losses at separation, and/or increased amount of waste water and/or passed through well or bore hole entire well production, passing along collecting header. Increase of pressure is provided so that all partially dehydrated oil with gas is supplied to collecting header. Possibility of oil falling in water discharge pipeline is eliminated.

EFFECT: technical result is increase in efficiency of cluster release and utilisation of produced water.

3 cl, 1 dwg

Description

The claimed invention relates to the field of equipment for the oil industry, and in particular to methods of cluster discharge and utilization of produced water in oil fields of a late stage of development, and may find application in sealed systems for the production and collection of oil wells.

A known method of cluster discharge and disposal of produced water, including supplying the products of one or more producing wells to a well for preliminary water discharge, measuring the amount of crude oil and gas, as well as the water cut of crude oil, oil and water densities entering the well for preliminary discharge water, dividing the products in it into partially dehydrated oil, gas and water, sending partially dehydrated oil and gas to a collection manifold, supplying discharged water to an injection well or water conduit / patent for Utility model No. 96176, IPC E21B 43/38 (2006.01); publ. 07/20/2010 /.

The disadvantage of this method is the lack of efficiency, due to the fact that the quality of the water supplied to the injection well or water conduit is poorly controlled, and its quantity is constant.

A known method of cluster discharge and utilization of produced water, including measuring the injectivity of an injection well, supplying the products of one or more producing wells to a well for preliminary water discharge, measuring the densities of the amount of crude oil and gas, as well as the water cut of crude oil, the densities of oil and water entering into the well for preliminary discharge of water, dividing the products into partially dehydrated oil, gas and water, sending partially dehydrated oil and gas to the collection manifold, discharge flow water in the injection well, in which the pressure of the water injected into the injection well may change / utility model patent No. 102056, IPC E21B 43/20 (2006.01); publ. 02/10/2011 /.

The disadvantage of this method is the lack of efficiency, due to the fact that the quality of the water supplied to the injection well is poorly controlled, and its quantity is constant.

The closest technical solution for the combination of essential features to the claimed invention and selected as a prototype is a method of cluster discharge and utilization of produced water, including measuring the injectivity of an injection well, supplying one or more production wells to a well or pit for preliminary water discharge, measuring the amount crude oil and gas, as well as water cut of crude oil, oil and water densities entering a well or pit for preliminary water discharge, division it contains borehole products for partially dehydrated oil, gas and water, the direction of partially dehydrated oil and gas to the collection reservoir, the discharge of discharged water into the injection well, the determination of the compatibility of the discharged water with the water of the formation into which it is injected from the injection well, with the compatibility of the injection water the well is equipped with a device for creating a water pressure sufficient to pump water into the formation, configured to change the flow and set to a minimum flow, determine the appropriate According to the quality of the discharged water, the geological conditions of the reservoir, if the quality of the discharged water is unsatisfactory, it is sent to the collection reservoir, if the quality of the discharged water is satisfactory, it is sent to the injection well, the amount of discharged water coming from the injection well is measured, then, with a selected constant or variable step, the flow of the device is increased to create water pressure, and this increase is as long as the quality of the discharged water satisfies the geologist to other reservoir conditions / RF patent No. 2548459, IPC E21B 43/20, 43/38, publ. 04.2015 /.

The disadvantage of this method is the lack of efficiency, due to the fact that the quality of the water supplied to the injection well is poorly controlled, and its quantity is constant.

The aim of the invention is to increase efficiency.

This goal is achieved by the fact that in the inventive method of cluster discharge and utilization of produced water, including measuring the injectivity of an injection well, supplying one or more production wells to a well or pit for preliminary water discharge, measuring the amount of crude oil and gas, as well as the water cut of crude oil, oil and water densities entering a well or pit for preliminary water discharge, dividing well products into partially dehydrated oil, gas and water in it, partially dehydrating direction oil and gas into the collection reservoir, supplying the discharged water to the injection well, determining the compatibility of the discharged water with the water of the formation into which it is injected from the injection well, if the water is compatible, the injection well is equipped with a device to create sufficient water pressure to inject water into the formation, made with the possibility of changing the supply and set to the minimum supply, determine the quality of the discharged water according to the geological conditions of the reservoir, with unsatisfactory quality If water is discharged, it is sent to a collection collector, with satisfactory quality of water discharged, it is sent to the injection well, the amount of discharged water coming from the injection well is measured, then, with a selected constant or variable step, the flow rate of the device for creating water pressure is increased, and this increase is made up to as long as the quality of the discharged water satisfies the geological conditions of the formation, in which when part of the well or pit for the preliminary discharge of water is partially but dehydrated crude oil and gas enters the collection manifold, then at the entrance to the well or pit for preliminary discharge of water, the pressure of the well products coming into it is increased by at least the amount of pressure loss during separation, and / or the amount of water discharged from the well or pit is increased for preliminary discharge of water, and / or pass through the borehole or pit for preliminary discharge of water all borehole products passing through the collection header. In addition, in some cases, the maximum water discharge capacity of a well or pit for preliminary water discharge is determined by discharging the discharged water into an empty or partially filled reservoir, for example, a dry injection well while sampling at the same time. In addition, in some cases, the demulsifier is fed to the partially dehydrated oil and gas that are discharged from the well or pit for preliminary water discharge.

When a partially dehydrated crude oil and gas are supplied from a well or pit for preliminary water discharge to a collecting manifold at the inlet of a well or pit for preliminary water discharge, increase the pressure of the well products coming into it at least by the amount of pressure loss during separation, and / or increasing the amount of discharged water at a well or pit for preliminary water discharge, and / or passing through a well or pit for preliminary water discharge of all well products passing through about the collector, allows you to send to the collector all partially dehydrated oil and gas, while ensuring the exclusion of the possibility of oil entering the water conduit, which increases efficiency.

Determining the maximum water discharge productivity of a well or pit for preliminary water discharge by discharging the discharged water into an empty or partially filled reservoir, for example, a dry injection well while sampling at the same time, reduces the time and cost of determining the maximum water discharge productivity, thereby increasing efficiency .

The supply of a demulsifier to partially dehydrated oil and gas leaving the well or pit for preliminary water discharge allows to reduce its consumption, thereby increasing efficiency.

The inventive method of cluster discharge and disposal of produced water is carried out by the following sequence of operations:

1) metering injectivity wells;

2) hydraulic tests (pressure testing) of the tightness of the well (pit) for preliminary discharge of water;

3) determining the compatibility of the discharged water with the water of the formation into which it is injected from the injection well;

4) when water is compatible, equipping the injection well with a device to create water pressure sufficient to pump water into the formation, for example, with an electric centrifugal pump - a “shifter”;

5) the implementation of the device to create a water pressure with the ability to change the flow, for example, a variable frequency drive for an electric centrifugal pump "shifter";

6) setting the minimum supply to the device to create water pressure, which before the start of the flow of water to it works in the "idle" mode;

7) supplying the products of one or more producing wells to a well or pit for preliminary water discharge;

8) measuring the amount of crude oil and gas, as well as the water cut of crude oil, the densities of oil and water entering a well or pit for preliminary water discharge;

9) measuring the pressure drop at the exit of the well or pit for preliminary discharge of water of partially dehydrated crude oil and gas and discharged water compared to the pressure of the crude oil and gas entering the inlet;

10) increasing at the entrance to the well or pit for preliminary water discharge the pressure of the well products (crude oil and gas) entering it at least by the amount of pressure loss during separation and / or increasing the amount of water discharged at the well or pit for preliminary water discharge , and / or passing through a borehole or pit for preliminary water discharge of all borehole products passing through a collection header;

11) dividing in the well or pit for preliminary discharge of water of the incoming products into partially dehydrated oil, gas and water;

12) direction from the borehole or pit for preliminary discharge of water of partially dehydrated oil and gas into the collection header;

13) determining the conformity of the quality of the discharged water at the exit from the well or pit for preliminary discharge of water to the geological conditions of the formation into which it is planned to be injected;

14) supply with unsatisfactory quality of discharged water at the exit of the well or pit for preliminary discharge of discharged water into the collection header;

15) supply with satisfactory quality of discharged water at the exit of the well or pit for preliminary discharge of water into the injection well;

16) measuring the amount of discharged water entering the injection well;

17) comparison of the amount of discharged water entering the injection well with its injectivity: if the amount of discharged water is greater than the injectivity, then reduce the amount of discharged water to injectivity; if the amount of discharged water is equal to the injectivity, then the amount of discharged water is stopped at the reached value; if the amount of discharged water is less than the injectivity, then the amount of discharged water is increased to the injectivity;

18) work in this mode for a certain period of time, for example a week, with periodic, for example 2 times a day, quality control of the discharged water;

19) the choice of a constant or variable step to increase the supply of the device to create water pressure;

20) increasing the supply of the device to create water pressure at the selected step;

21) repetition of operations 6) ... 20);

22) repetition of operations 20) and 21) until the quality of the discharged water satisfies the geological conditions of the formation;

23) the creation in cases of periodic shutdown and / or inclusion of oil wells of the bush of pressure of the discharged water at the exit from the well for preliminary discharge of water is higher than in the collection header (this operation is additionally included in operation 13);

24) if the maximum water discharge capacity of a well or pit for preliminary water discharge is determined by discharging the discharged water into an empty or partially filled reservoir, for example, a dry injection well while sampling at the same time, then the corresponding supply is installed on the device for creating water pressure (it is additionally included in operation 6);

25) supply of a demulsifier to partially dehydrated oil and gas leaving the well or pit for preliminary water discharge;

26) the implementation in cases of a high gas content in crude oil or the possibility of gas plugs getting into the degassing of discharged water, for example, by vibrating elements of a downhole water discharge installation (to create waves) to separate dissolved gas (this operation is further included in operation 12).

Example

One of the possible embodiments of the device for implementing the inventive method of cluster discharge and disposal of produced water is shown in figure 1.

A production supply pipe 2, a partially dehydrated oil and gas drain pipe 3 and a water drain pipe 4 are connected to a pit for preliminary water discharge 1, and a water drain pipe 4 includes a device for determining the quality of water 5 and a valve 6. A pipe for drainage of a partially dehydrated oil and gas 3 connected to the drain pipe 4 bypass line 7 with a valve 8. The drain pipe 4 is connected to the injection well 9 through a string of tubing 10. On the string of tubing 10 a shifter pump is shifted 11. The outlet of the tubing string 10 is located below the packer 12.

This device, carrying out the inventive method of cluster discharge and disposal of produced water, works as follows.

In the pit for preliminary water discharge 1, the production of oil wells — a water-oil and gas mixture — enters through a production supply pipe 2. On the pump-changer "11, the minimum flow rate is set (for example, 35 Hz with a frequency range of 35-50 Hz - the flow increases with increasing frequency), and it operates in the" idle "mode. In this case, the valve 6 is closed, and the valve 8 is open. In the downhole water pre-discharge unit 1, the incoming oil-gas mixture is divided into partially dehydrated oil, gas and water. Partially dehydrated oil and gas are discharged through the drain pipe 3. The discharged water through the drain pipe 4 enters through the bypass line 4 into the drain pipe for the partially dehydrated oil and gas 3. The quality of the discharge water is determined by a device for determining the quality of water 5. If the quality of the discharge water satisfies the geological conditions of the reservoir into which the injection is carried out, the valve 6 opens and the valve 8 closes. Water enters the pump-changer 11 in the injection well 9. The pump-pervert 11 creates sufficient water pressure for injection into the formation, and then it enters the well zone below the packer 12 through the tubing string 10 the operation of the device for implementing the inventive method of cluster discharge and utilization of produced water during a certain period of time, for example a week, the supply of the pump-changer 11 is increased (for example, up to 40 Hz with a frequency range of 35-60 Hz) and the operations are repeated.

Thus, the claimed method of cluster discharge and disposal of produced water is more efficient than the prototype due to the quality control of the water supplied to the injection well and the possibility of regulating its supply. The inventive method of cluster discharge and disposal of produced water eliminates the injection of incompatible water into the formation. The inventive method of cluster discharge and disposal of produced water eliminates the injection into the reservoir of low-quality water.

Claims (3)

1. A method of cluster discharge and utilization of associated produced water, including measuring the injectivity of an injection well, supplying the products of one or more producing wells to a well or pit for preliminary water discharge, measuring the amount of crude oil and gas, as well as the water cut of crude oil, oil and water densities flowing into the well or pit for preliminary water discharge, dividing the well products in it into partially dehydrated oil, gas and water, sending partially dehydrated oil and gas to the collection manifold, supply thrown water into the injection well, determining the compatibility of the discharged water with the water of the formation into which it is injected from the injection well, when the water is compatible, the injection well is equipped with a device to create sufficient water pressure to pump water into the formation, configured to change the flow and set to a minimum supply, determine the compliance of the quality of the discharged water with the geological conditions of the reservoir, if the quality of the discharged water is unsatisfactory, it is sent to a collection tank Ohr, with satisfactory quality of the discharged water, it is sent to the injection well, the amount of discharged water entering the injection well is measured, then, with the selected constant or variable step, the supply of the device for creating water pressure is increased, and this increase is made until the quality of the discharged water satisfies the geological conditions of the formation, characterized in that when partially dehydrated crude oil with gas is supplied from a well or pit for preliminary water discharge is fed into the prefabricated collector, then at the entrance to the well or pit for preliminary water discharge, the pressure of the well products entering it is increased by at least the amount of pressure loss during separation, and / or the amount of water discharged to the well or pit for preliminary water discharge is increased, and / or they pass through a borehole or pit to preliminarily discharge water all borehole products passing through the collection manifold, and the pressure increase is provided in such a way that all partially dehydrated oil and gas sent to the prefabricated collector, while eliminating the possibility of oil getting into the water drainage pipeline. 2. The method according to p. 1, characterized in that the maximum productivity for discharging water from a well or pit for preliminary water discharge is determined by discharging the discharged water into an empty or partially filled reservoir, for example, a dry injection well while sampling. 3. The method according to p. 1 or 2, characterized in that the demulsifier is fed into the partially dehydrated oil and gas that is discharged from the well or pit for preliminary water discharge.

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