RU2525563C1 - Processing of wellbore zone of formation - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: in compliance with this method, two rotary pumps are lowered on flow string. Said pumps are driven by downhole motor with two pro-shaft extensions. Top rotary pump feeds into flow string. Bottom pump serves to break bonds of colmatant and to discharge it in, for example, sludge trap. Top pump serves to change well fluid dynamic level and to force produced fluid to the surface. Development process is controlled from the surface by, for example, control station with frequency inverter of downhole motor.

EFFECT: higher efficiency.

2 dwg

Description

The claimed invention relates to the oil and gas industries and can be used in the treatment of the bottom-hole formation zone to intensify the flow of formation fluid to the well. It can also be used to induce inflows and to study oil wells coming out of drilling or overhaul.

The treatment of the bottom-hole zone of the formation is carried out only in technically sound wells, provided that the production string and cement ring are tight, which must be confirmed by research.

A known method of processing the bottom-hole zone of an oil reservoir, comprising installing in the well a column of tubing, in which an acid reagent is injected through the tubing string containing, wt.%: Hydrochloric acid 8-16, hydrofluoric acid 1.5-18 , surfactant 0.3-2.5, corrosion inhibitor 0.1-2.0, solvent, rest, displacement, technological exposure and removal of reaction products by depressive action, for example, by deep-well jet pumps (RF Patent No. 2346153, Е21В 43/27, 2007).

The disadvantage of this method is the low degree of predictability of effectiveness, due to the fact that:

- during the treatment of the bottom-hole zone of the formation, production of the well products is not performed;

- the processing complexity is not ensured, the process is multi-stage, requiring a large amount of time, disruptions in the exposure of technological modes at certain stages of the process are possible, which negatively affects the technical and economic efficiency of the method;

- it is not allowed to carry out processing in high-temperature formations (above 100 ° C).

A known method of processing the bottom-hole zone of the formation, including installing a string of tubing in the well, in which the geological, physico-chemical properties of the rocks of the reservoir and formation fluids are performed, treatment of the bottom-hole zone of the reservoir by injecting the first and second chemical reagents, holding the well for the reaction time of chemical reagents with the rocks of the reservoir and reservoir fluids, cleaning the bottom-hole zone of the reservoir from reaction products when the well is put into operation, for intensification of the influx removes loosely bound water from the bottom-hole zone of the formation and hydrophobizes the pore space of the rocks, for which a 50% methanol solution is pumped as the first reagent and left to react, after which the reaction products are forced deep into the formation, while the second reagent performs further hydrophobization bottomhole zone and increase its gas permeability, for which an aqueous solution of a surfactant concentration of 1-3% is used, the reaction products are extracted from formation reservoir together with formation gas during well development, which is carried out using donor well gas or inert gas (RF patent 2460872, ЕВВ 43/16, 2012).

The disadvantage of this method is the reduced efficiency due to the fact that during the treatment of the bottom-hole formation zone, production of the well products is not performed.

The closest to the claimed invention in technical essence and the achieved result is a method for treating the bottom-hole zone of the formation, including installing in the well a string of tubing with suspended submersible equipment, which contains a pressure accumulator with an elastic ball, a pump drive, a medium separator, a deep pump with suction and discharge valves, and the pressure accumulator in the lower part is equipped with a movable seat with a return spring, and the pump and depth pump drive made with equal-sized pistons rigidly connected to each other by a hollow stem with valves at both ends and one or more radial holes located above the piston of the deep pump, and one or more radial holes are located at the bottom of the pump drive (RF patent 2267609, ЕВВ 43 / 25, 2006).

The proposed invention solves the problem of improving the technological and economic efficiency of the SCR (treatment of the bottom-hole zone).

This problem is solved by a new method of treating the bottom-hole zone of the formation, including installing in the well a string of tubing with submersible equipment suspended on it, two centrifugal pumps are lowered on the tubing string, the drive of which is carried out by a submersible electric motor with two outputs installed between them shaft for power take-off, feeding from the upper centrifugal pump is made into the tubing string, while the lower centrifugal pump serves to breaking collimatant bonds and its discharge, for example, into the sludge trap, and the upper pump is designed to change the dynamic level of the fluid in the well and supply the produced fluid to the surface; control and management of the technological process of development is carried out from the surface, for example, by a control station.

The increase in efficiency in the claimed invention is achieved by:

- continued pumping of products from the well during the treatment of the bottom-hole formation zone;

- the creation of predetermined depressions on the reservoir according to the estimated schedule, ensuring maximum destruction and removal of the mud at the beginning of the process to create conditions for the flow of oil from the reservoir at the end of the process;

- control of the technological process of well development at the mouth using a control station with a telemetry system and a flow sensor;

- construction of pressure recovery curves and level recovery curves without additional research;

- determining the inflow profile during the process;

- the possibility of accumulation of sludge in a special sludge trap and its removal to the surface after completion of the development process;

- transportation of well production into the oil gathering system under its own pressure.

The method of processing bottom-hole formation zone is as follows. A column of tubing is installed in the well with submersible equipment suspended on it. Two centrifugal pumps are lowered on the tubing string, the drive of which is carried out by a submersible electric motor installed between them with two shaft outputs for power take-off. The submersible motor is turned on and both centrifugal pumps are driven. At the inlet of the lower centrifugal pump, products come from under the packer installed above the top of the formation, while a depression is created on the formation, which ensures that the bottomhole pressure drops below the saturation pressure. Due to the formation of gas in the formation in the near-wellbore zone, a significant depth occurs, while the destroyed and removed colmatant, which is in the solid phase, gets into the sludge trap, and the colmatant, which is in the liquid phase (emulsion) together with the produced liquid, is discharged into the annulus above the packer.

Further, the product enters the upper pump, from where it then enters the tubing string. Additionally, the upper pump makes a change in the dynamic fluid level in the well due to a change in flow. Monitoring and control of the technological process of development is carried out from the surface, for example, by a control station.

One of the possible embodiments of the device for implementing the method of processing the bottom-hole formation zone is shown in FIG. The control station is shown in figure 2.

A device for implementing a method of treating a bottomhole formation zone includes a sludge trap 1 mounted on a packer 2, a flowmeter 4 is installed on the tubing string 3. The lower centrifugal pump 5 is connected to the submersible motor 7 through the lower hydraulic protection 6, and the upper centrifugal pump is connected to its upper part 9 through the upper hydraulic protection 8. In the well 10, the upper pump 9 of the tubing string 3 is connected to the wellhead 11, the control is carried out by the control station 12.

A device for implementing the method of processing bottom-hole formation zone works as follows. Downhole products through a sludge trap 1 and a flow meter 4 through a tubing string 3 from under the packer 2 are fed to the intake of the lower pump 5. The measured fluid at the outlet of the lower pump 5 is discharged into the annulus, from where it enters the intake of the upper pump 9 and then the tubing string enters the wellhead 10. Control is carried out by a frequency converter in an electric motor control station.

Thus, the inventive method of processing the bottom-hole formation zone allows to increase efficiency. In addition, the proposed SCF technology allows for the challenge of inflow and exploration of oil wells leaving drilling or major repairs, including for wells operating in simultaneous and separate operation mode. The complex of information material obtained using an autonomous research unit allows not to carry out additional GIS.

Claims (1)

A method of treating the bottom-hole zone of the formation, including installing in the well a string of tubing with submersible equipment suspended on them, characterized in that two centrifugal pumps are run on the tubing string, the drive of which is carried out by a submersible electric motor installed between them with two shaft outputs for power take-off, feeding from the upper centrifugal pump is carried out into the tubing string, while the lower centrifugal pump serves to break the colm bonds tant and its discharge, for example, into the sludge trap, and the upper pump is designed to change the dynamic level of the fluid in the well and supply the produced fluid to the surface; control and management of the technological process of development is carried out from the surface, for example, by a control station.

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