RU2481466C1 - Method for oil production - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: production method includes descending of tubing string with bottom-hole pump and packer into the well, packer location above the interval of production formation, packer installation and oil extraction by bottom-hole pump. According to invention there used is a low flow rate well as a well, bottom-hole pump is equipped with bottom-hole pressure gauge and located not higher than production formation interval, at oil extraction in under-packer zone there maintained is the negative bottom-hole pressure.

EFFECT: increase of well productivity.

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Description

The invention relates to the oil industry and may find application in oil production.

There is a method of operating a well in which tubing columns with an electric centrifugal pump are lowered into the well and fluid is taken from the well. The tubing string is equipped with a packer located above the pump; the pump is replaced with a pump having a larger head. The column of tubing is lowered into the well to a depth corresponding to the height of the liquid column raised by the replaced pump. Install the packer and take the liquid from under the packer (RF Patent No. 2425963, publ. 08/10/2011).

Closest to the proposed invention, the technical essence is a method of producing highly viscous oil from a directional well by cyclic injection of steam into the formation, including drilling an upstream section of the well in a production well, placing tubing strings in this section with centralizers for cyclic coolant injection through them and production casing with a pump for oil extraction, the descent of the tubing string, which perform thermally insulated. The ascending section of the well is equipped with a filter with two open areas at the beginning and end of this section, and the annulus between the filter and the pipe string and between the open areas is isolated by a packer, while the pump is located in the production casing of the well above the filter within the bottom of the productive layer, but lower slaughter of the ascending site. The bottom hole, in turn, is set below the top of the formation vertically at a distance of not less than 2 m. After the coolant is injected, exposure is performed to distribute heat in the formation, oil is taken by the pump to allow a reasonable reduction in flow rate, after which the steam injection cycle is repeated (RF Patent No. 2436943 , publ. 12/20/2011 - prototype).

A disadvantage of the known methods is the impossibility of producing viscous oil at low reservoir productivity, as a result of which it is necessary to transfer the pump to periodic mode and often with very long downtime intervals. The flow rate of the well is low.

The proposed invention solves the problem of increasing the flow rate of the well.

The problem is solved in that in the method of oil production, including the descent into the well of a string of tubing with a sucker rod pump and a packer, placing the packer over the interval of the reservoir, setting the packer and taking oil with the sucker rod pump, according to the invention, the sucker rod pump is not placed above the interval of the reservoir, and during the selection of oil in the sub-packer zone maintain negative bottomhole pressure.

SUMMARY OF THE INVENTION

When producing viscous oil from a low-rate formation, it is necessary to transfer the deep-well pump to a periodic mode of operation. This negatively affects the operation of the pump, requires constant operator intervention in the process of starting the pump. With such work, contaminants accumulate in the well, which makes it necessary to stop and clean the well. Well production remains low. The proposed invention solves the problem of increasing the flow rate of the well. The problem is solved as follows.

A column of tubing with a packer and a sucker rod pump at the end is lowered into an oil well. The pump is placed no higher than the interval of the reservoir: in the interval of the reservoir or below the interval of the reservoir. The packer is placed over the interval of the reservoir. Set the packer. The pump is connected by a rod string to a rocking machine at the wellhead and oil is sampled by a sucker rod pump. During the selection of oil in the sub-packer zone, the bottomhole pressure is gradually brought to a negative value and the well is operated in this mode, i.e. during oil production maintain negative bottomhole pressure. As a result, the flow rate of the well increases several times. The pump is operated continuously.

Concrete example

In an oil producing well with a production string of 146 mm in diameter, the interval of the productive formation was opened by perforation at a depth of 972–961 m. Oil with a viscosity of 295 cP is produced by a well. An assembly consisting of a tubing string 73 mm in diameter, a 25-175ТНМ deep-well pump at the end of the string, and a PRO-YamO packer located above the pump are lowered into the well. The packer is placed at a depth of 948 m, while the pump is in the interval of the reservoir. Seal the packer. The sub-packer space hermetically combines the perforation zone at the depth of the production string and the pump intake. The pump is driven through the rod column by the PNShT-60 rocking machine. Start the pump to work. When the pump is operating in a sub-packer space, a negative pressure is achieved in the range from -0.09 to -0.11 MPa.

Prior to the application of the above arrangement, the well was operated periodically due to high viscosity and low fluid flow. To control the pressure in the well, an autonomous depth gauge was lowered into the sub-packer zone of pump intake.

As a result, the flow rate of the well increased from 1.1 to 3.2 m ³ / day.

The application of the proposed method allowed to increase the inflow from the formation into the well, transfer the well from a periodic mode of operation to a permanent one, and also protect the sucker rod pump from jamming due to dry operation in a weakly supply well.

The application of the proposed invention will increase the flow rate of the well.

Claims (1)

A method of producing highly viscous oil, including the descent into the well of a string of tubing with a sucker rod pump and a packer, placing a packer over the interval of the reservoir, setting the packer and oil selection with a sucker rod pump, characterized in that the wells use a low-flow well, a sucker rod the pump is equipped with a depth gauge and placed no higher than the interval of the reservoir, and during the selection of oil in the under-packer zone, negative bottomhole pressure is maintained.