RU2418942C1 - Procedure for well development - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: at development of well pressure is periodically sunk without shutdown of immersed pump station and filtration equilibrium mode is periodically restored. Well space between interval of perforation and pump equipment is preliminary and temporarily disconnected into an upper and lower one to create periodical pressure sink without shutdown of the immersed pump station. Thus flow of liquid into the well stops and pressure is equalised in borehole environment. By withdrawing liquid with pump from upper space of the well above the place of disconnection there is created pressure sink in well. At restoration of the equilibrium mode of filtration upper and lower space of the well are connected creating rapid pressure sink in borehole environment and rapid restoration of liquid flow into the well. Fluid is continued to be withdrawn with the pump.

EFFECT: increased efficiency of procedure due to reduced production watering.

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Description

The invention relates to the oil industry and may find application in the operation of a producing well.

There is a method of operating a well, according to which separate pumping of oil from the upper productive formation to the day surface by an upper pump installed at the maximum working height of the operating mode and water into the water-saturated plantar area or the underlying water-absorbing formation by the lower electric centrifugal pump, facing down and having a liner bottom with a packer installed above the roof of the water-absorbing formation or in the plantar area of the formation. The ratio of the productivity of the lower and upper pumps is selected depending on the ratio of the amount of water and oil entering the well. The total performance of the pumps is selected from the conditions of gravity separation of the formation fluid in the well into oil and water and pumping water containing no oil with the lower pump. Between the upper and lower pumps at the working depth of the depression mode, an average electric centrifugal pump is installed with a capacity greater than that of the upper pump. Periodically change the operating mode of the well to the depression mode, for which the upper pump is turned off and the middle and lower pumps are turned on. The water-saturated bottom region of the formation or the water-absorbing formation is pre-punched below the oil-water contact at a distance of at least 5 m. Two groups of holes are made in the string of tubing between the pumps. The lower group of holes is placed above the perforation of the reservoir at a distance ranging from 50 to 100 m. The upper group of holes is placed at a distance from the lower group of holes in the range from 50 to 300 m (RF patent No. 2382181, publ. 02.20.2010).

The method is complicated in hardware design and in the management of equipment to maintain well operation modes. The method allows to separate the fluid flows into oil and water, but it does not solve the problem of reducing the water content of the produced products.

Closest to the proposed invention in technical essence is a method of developing an oil reservoir, which includes taking fluid through production wells, pumping a working agent through injection wells, periodic depression in production wells without stopping submersible downhole pumping equipment, and periodically restoring the equilibrium filtration mode. Production wells are equipped with two deep pumps of different capacities. A pump of lower capacity is placed on top of the working depth of the equilibrium filtration mode. A pump with a higher capacity is placed at the bottom at the working depth of the depression mode. The equilibrium filtration mode provides a pump with a lower capacity when the pump is turned off with a higher capacity. The depression mode provides the pump with higher performance when the pump is turned off with lower productivity and with a decrease in the liquid level in the well below the working depth of the equilibrium filtration mode. In this case, when switching from the depression mode to the equilibrium filtration mode, the upper pump is put into operation immediately after reaching the liquid level in the well, the pump depth of the lower productivity, while maintaining the fluid flow in the well (RF patent No. 2320860, publ. 2008.03.27 - prototype).

The method is ineffective due to the fact that when creating a depression, the pressure gradient practically does not change, there is no pressure equalization in the near-wellbore space due to the lack of stopping the fluid flow. Only the acceleration of the fluid flow occurs, which helps to accelerate the passage of fluid through the washed channels and practically does not affect the reserves in low-permeability zones and blocks between cracks. The water content of the extracted products varies slightly.

The proposed invention solves the problem of reducing the water content of the produced products by stopping the fluid flow and equalizing the pressure in the near-wellbore zone and drastically reducing the pressure with simultaneous fluid withdrawal.

The problem is solved in that in the method of operating the well, comprising periodic depression in the well without stopping the submersible downhole pumping equipment and periodically restoring the equilibrium filtration mode, according to the invention, to create periodic depression in the well without stopping the submersible downhole pumping equipment previously between the perforation interval and the pumping equipment the borehole space is temporarily divided into upper and lower, which organize the stop of the fluid flow in borehole and pressure equalization in the near-wellbore space, and depression in the well is created by pumping fluid from the upper space of the well above the place of separation, when the equilibrium filtration mode is restored, the upper and lower space of the well is reported, which organizes the creation of a sharp depression on the near-wellbore zone and a sharp restoration of fluid flow in well, and continue pumping fluid.

SUMMARY OF THE INVENTION

In the classic operation of a producing well, when there is a steady pressure gradient in the near-wellbore zone, the fluid flows through the same highly permeable channels and fractures. At the same time, oil from low-permeability zones and blocks between highly permeable channels and cracks remains undeveloped. As a result, a highly permeable part is washed with water and a high water cut of the produced products occurs. Existing methods of operating wells and developing oil deposits make it possible to force the selection of liquid from the well, however, there is no change in pressure sufficient for oil to escape from low-permeability zones and blocks to high-permeability and fracture zones. It is possible to force oil from blocks and low-permeability zones to enter low-permeability zones and fractures and then to the well only by stopping the flow, equalizing the pressure and then drastically reducing the pressure in the near-wellbore space. A sharp decrease in pressure contributes to the release of oil from low-permeability zones and blocks and to a decrease in the water content of produced products. The proposed invention solves the problem of reducing the water content of the produced products by stopping the fluid flow and equalizing the pressure in the near-wellbore zone and drastically reducing the pressure with simultaneous fluid withdrawal. The problem is solved as follows.

Pumping equipment is lowered into the production well below a standard location and closer to the perforation interval. Between the perforation interval and the pumping equipment, the borehole space is temporarily divided into upper and lower, for example, by setting a packer in the production string equipped with control from the wellhead, setting a jumper in the production string with a valve that can be opened by pressing when lowering the pipe string or rods, etc. . This organizes the stopping of fluid flow into the well. In the near-wellbore zone, when the fluid flow is stopped, pressure equalization occurs. In this case, the pressure is evened out between the high-permeability and low-permeability zones, between the fractured part and the blocks. When the disconnection is established, they continue to draw fluid from the well with a pump from the upper space of the well above the place of separation. In the well above the place of separation, depression is created. When the liquid level is reduced to a predetermined value (the limit may be the pressure of oil saturation with gas or other features of the reservoir), preferably to the pump level, the upper and lower space of the well is reported, thereby organizing the creation of a sharp depression on the near-wellbore zone and a sharp restoration of the fluid flow into the well. At the same time, the pump continues to take fluid. The creation of a sharp depression contributes to the creation of a pressure differential between the high-permeability and low-permeability zones, between the fractured part and the blocks, and the flow of oil from the low-permeability zones and blocks to the high-permeability zones and fractures and further to the well. The water content of the extracted products is reduced. Then the well is operated in the normal mode until the water cut increases, at which the water cut reduction measures are repeated.

Concrete example

After watering the produced products up to 90% into the production well with a perforation interval at a depth of 820-830 m, cased with a production string with a diameter of 168 mm, the assembly consisting of a device for interval testing of production casing (packer), rigidly connected through the shank of the tubing pipes with a sucker rod pump type 25-175-RHAM-12-4-2-2, located above and capable of supplying fluid from the well with a flow rate of 8-12 m ³ / day., and tubing string. The packer cable is fixed to the outer surface of the tubing string. The packer is placed at a depth above the perforation interval of 25 m. The pump is placed at a depth of 65 m above the perforation interval. The well is equipped with a controller and two depth gauges with the ability to transfer data to the mouth. The pump is started up and the well fluid is selected through the tubing string. The cable is energized and the packer motor is turned on, which packs and divides the borehole space into upper and lower. Continue to pump out the borehole fluid with a pump from the upper space of the borehole until the liquid level in the borehole drops to a depth of 700 m. A command is sent via cable to the packer electric motor, the packer is unpacked and the upper and lower borehole space is reported. In this case, the pump continues to pump out the well fluid. Continue to operate the pump as normal.

As a result, the water cut of the extracted products decreased from 90 to 65%.

The application of the proposed method will solve the problem of reducing the water content of the extracted products.

Claims (1)

A method of operating a well, including periodic depression in the well without stopping the submersible downhole pumping equipment and periodically restoring the equilibrium filtration mode, characterized in that in order to create a periodic depression in the well without stopping the submersible downhole pumping equipment, the borehole space is temporarily divided between the perforation and pumping equipment upper and lower than organizing a stop of fluid flow into the well and alignment phenomena in the near-wellbore space, and depression in the well is created by pumping fluid from the upper space of the well above the place of separation, when the equilibrium filtration mode is restored, the upper and lower spaces of the well are reported, thereby organizing the creation of a sharp depression on the near-wellbore zone and a sharp restoration of fluid flow into the well, and continue pumping fluid.