RU2494232C1 - Operating method of production well of high-viscosity oil - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: according to the proposed method, a layout consisting of the following in upward direction is lowered to the well: a lower perforated connection pipe, a valve, a drain valve, a packer, a bottom-hole pump, a tubing string, an upper perforated connection pipe and a line of rods. The bottom-hole pump is brought into operation under action of movements of the line of rods. Supply of high-viscosity oil is performed to the well head via the tubing string and through upper perforated connection pipe via inter-tube space. Periodic straight flushing is performed by pumping of flushing liquid via the tubing string, sampling is performed through upper perforated connection pipe and inter-tube space and back flushing is performed by lifting the pump above upper perforated connection pipe. Pumping of flushing liquid is performed via inter-tube space and sampling is performed through upper perforated connection pipe and tubing string.

EFFECT: providing the possibility of bringing bottom-hole equipment to working position at sticking of the line of rods by straight or back flushing of the well without lifting that equipment from well.

1 ex, 1 dwg

Description

The invention relates to the oil industry and may find application in the operation of a well through which highly viscous oil is produced.

Known sucker rod pump, which contains a cylinder, upper and lower moving hollow plungers, suction and discharge valves, a filter with holes. The upper and lower plungers are made of the same diameter. The pump is additionally equipped with a hollow rod, which is located between the upper and lower plungers of the same diameter. The hollow rod at both ends is connected by means of adapters with holes to the rod, which passes through the cavity of the upper and lower plungers. The upper end of the rod located above the upper end of the upper plunger and the lower end of the rod located below the lower plunger are made with an expanding cone-shaped thickening and form valves with the ends of the plungers. The bottom valve has the function of discharge and suction. Washers with holes are installed on the rod between the hollow rod, upper and lower plungers. In the middle of the upper and lower plungers of the same diameter, rod deflection washers with holes are installed. The upper and lower plungers are made of elastic material (RF Patent No. 2289724, publ. December 20, 2006).

Closest to the proposed invention in technical essence is the method of operation of a sucker rod pump installation described in the patent of the Russian Federation No. 2161268, published: 12/27/2000 - prototype. The installation is equipped with a pump with a two-stage cylinder, in which two hollow plungers of different diameters are located, interconnected and forming working chambers. The lower stage of the plunger is weighted with a load located outside the pump below its receiving part, and has a larger diameter at a length equal to the stroke length of the plunger.

A disadvantage of the known methods is the freezing of the rod string and the inability to bring the rod string to the working position by direct or reverse flushing of the well.

The proposed invention solves the problem of ensuring putting into working position when the rod string hangs by direct or reverse flushing of the well without lifting the pumping equipment from the well.

The problem is solved by a method of operating a highly viscous oil producing well, including a descent into the well of an arrangement consisting of a bottom perforated nozzle, a valve, a relief valve, a packer, a rod pump, a tubing string, an upper perforated nozzle and a rod string, putting the rod into operation the pump under the action of displacements of the rod string, the supply of highly viscous oil to the wellhead through the tubing string and through the upper perforated pipe along the annulus space, periodic direct flushing by pumping flushing fluid through the tubing string and withdrawal through the upper perforated nozzle and annular space and backwashing by lifting the pump above the upper perforated nozzle, injecting flushing fluid through the annular tubing and withdrawing through the upper perforated tubing and pump tubing compressor pipes.

SUMMARY OF THE INVENTION

When producing highly viscous oil, the rod string hangs, the rod breaks, and the oil supply is reduced or completely absent. These factors lead to an increase in resuscitation measures to restore well operation, oil losses, an increase in the cost of resuscitation measures and underground well repair. Existing technical solutions do not fully eliminate the negative factors. The proposed invention solves the problem of ensuring putting into working position when the rod string hangs by direct or reverse flushing of the well without lifting the pumping equipment from the well. The problem is solved as follows.

The arrangement shown in FIG. 1 is lowered into the well.

The layout consists from bottom to top of the lower perforated pipe 1, valve 2, the relief valve 3, the packer 4, the insert rod pump 5, the tubing string 6, the upper perforated tubing 7 and the rod string 8. The layout is located in the production casing 9 of the well that opened reservoir 10.

The layout works as follows.

From the wellhead from a rocking machine (not shown), a rod string 8 is driven back and forth by means of which a rod pump 5 is brought into operation, which is a highly viscous oil from the reservoir 10 through the lower perforated pipe 1, valve 2, past the knockdown valve 3 through the packer 4 feeds into the upper perforated pipe 7 and the tubing string 6. In the upper perforated pipe 7, high-viscosity oil is divided into two streams. One highly viscous oil flow is directed along the tubing string 6 to the wellhead, another flow through the upper perforated nozzle 7 flows into the annulus between the tubing string 6 and production string 9 and is routed through the annulus to the wellhead.

In the event of a freezing of the rod string 8, forward or backwash is carried out. Flushing helps release the rod string 8 and translates into a mobile state.

With direct flushing, flushing fluid is supplied through the tubing string 6, squeezed through the upper perforated pipe 7 into the annulus and further to the wellhead.

When backwashing, the plug-in sucker rod pump 5 is raised above the upper perforated nozzle 7 and the flushing fluid is fed into the annulus. The flushing fluid passes through the upper perforated pipe 7, through the raised pump 5 and the tubing string 6 to the wellhead.

As a result of washing, it is possible to free the rod string and return the layout to its working position.

Concrete example

An oil producing well is exploited that has uncovered a productive formation at elevations of 1007.9-1017.3 m. The well is cased with a production string of 146 mm in diameter. The layout according to FIG. 1 is launched into the well. A pump of the brand 25-175-RHAM-14-4-4 was used as an insert rod pump. The layout was launched on a tubing string with a diameter of 73 mm. The produced oil has a viscosity of 472 cst, and the water cut of oil is 8%. The oil production rate is 1.62 tons / day.

When the rod string hangs, the well is washed with direct and reverse flushing. As a washing liquid, salable oil is used. The flushing time is 3 hours. After washing, boom freezing is eliminated. A well is put into operation.

Application of the proposed method will ensure bringing into working position when the rod string hangs by direct or reverse flushing of the well without lifting the pumping equipment from the well.

Claims (1)

A method of operating a highly viscous oil producing well, including a descent into a well of an arrangement consisting of a bottom perforated nozzle, a valve, a knockout valve, a packer, a rod pump, a tubing string, an upper perforated nozzle and a rod string, putting the rod pump under the action of the rod string movements, the supply of highly viscous oil to the wellhead along the tubing string and through the upper perforated pipe along the annulus, period direct rinsing by pumping flushing fluid through the tubing string and withdrawing through the upper perforated pipe and annular space and backwashing by lifting the pump above the perforated tubing; injecting flushing fluid through the tubing and sampling through the upper perforated pipe and tubing string .

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