RU2258134C1 - Treatment method for bottomhole zone of injection well - Google Patents

Abstract

FIELD: oil production, particularly methods or apparatus for obtaining products from wells.

SUBSTANCE: method involves displacing working agent under elevated pressure and performing curing thereof. For bottomhole zone treatment bath for working agent having 4-6 m³ volume is provided in perforation interval and curing time is up to 9 hours. Working agent is displaced by discharge water in impulse draining mode including pressure increase at well head up to 11-13 MPa and pressure drop operations, wherein number of impulses is 30-50. Then 20-40 m³ of 3-8% hydrochloric acid solution is displaced, curing is performed for not more than 4 hours and discharge water is injected in amount of 20-40 m³.

EFFECT: increased intake capacity of well.

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Description

The invention relates to the oil industry and may find application in the treatment of the bottom-hole zone of an injection well to increase its injectivity and, as a result, provide enhanced oil production due to pressure parameters in reacting production wells.

A known method of processing the bottom-hole zone of the well, including the injection into the bottom-hole zone of the distillate and technological exposure (Application for invention No. 2002135664, publ. 2004.06.27).

A known method of processing the bottom-hole zone of a well, including injecting distillate into the well, first technological aging, injecting a 0.5-5% solution of nonionic surfactant in associated Devonian water into the reservoir, second technological aging and depression perforation (RF patent No. 2135758 publ. 1999.08.27).

The closest to the proposed invention in technical essence is a method of processing the bottom-hole zone of a well, which includes injecting a working agent - distillate at a bottomhole pressure 10-20% lower than the back pressure on the bottom of a well at opening, holding technological exposure to reduce pressure at the wellhead to atmospheric, injection 0.5-5% solution of nonionic surfactant in the oilfield produced water Devonian density 1,06-1,09 g / ^cm3, prodavku into the formation until the pressure values at the bottom of the well not more than 30% of the back pressure at the bottom of the well during opening, an increase in the flow rate of the surfactant solution injection until stabilization of the injection pressure, and when the pressure at the bottom of the well is more than 30% of the back pressure at the bottom of the well when opening, the bottom pressure decreases to hydrostatic, conducting additional perforation in the same interval of the reservoir under the layer of the surfactant solution, again pushing the surfactant solution into the reservoir and increased ix flow pumping pressure to stabilize (RF Patent №2066372, publ. 1996.09.10 - prototype).

Known methods allow you to process the bottom-hole zone with reduced throttle response. However, the implementation of methods in wells with practically zero injectivity leads to a minimal result for increasing well productivity.

The proposed invention solves the problem of increasing the injectivity of the injection well.

The problem is solved in that in the method for processing the bottom-hole zone of the injection well, comprising pushing the working agent at pressure and holding technological exposure, according to the invention, before selling the working agent, they organize a working agent bath in a volume of 4-6 m ³ in the perforation interval with technological holding up to 9 hours , the squeezing of the working agent is carried out by wastewater in the pulse drainage mode: increasing the pressure at the mouth to 11-13 MPa - depressurizing, the number of pulses is prescribed 30-50, the squeezing is carried out in 3-8% races a solution of hydrochloric acid in a volume of 20-40 m ³ , carry out technological exposure for no more than 4 hours and pump 20-40 m ^{3 of} waste water.

The features of the invention are:

1. the organization of the bath of the working agent in the amount of 4-6 m ³ in the perforation interval;

2. technological exposure;

3. the same until 9 o'clock;

4. selling a working agent;

5. selling the working agent with wastewater;

6. the same in pulsed drainage mode: pressure increase at the mouth to 11-13 MPa - pressure relief;

7. number of pulses - 30-50;

8. selling 3-8% hydrochloric acid in a volume of 20-40 m ³ ;

9. carrying out technological exposure no more than 4 hours;

10. pumping 20-40 m ^{3 of} waste water.

Signs 2, 4 are common with the prototype, signs 1, 3, 5-10 are the essential distinguishing features of the invention.

SUMMARY OF THE INVENTION

When developing an oil deposit, sewage is pumped through injection wells containing a large amount of oil product residues, sulfides and iron oxides in a suspended solid state, etc. All this is deposited in the bottom-hole zone of the injection well, reduces injectivity and adversely affects the displacement of oil from the reservoir. Existing methods for increasing the injectivity of the injection well lead to a minimal effect. The proposed method solves the problem of increasing the injectivity of the injection well. The problem is solved as follows.

When processing the bottom-hole zone of the injection well, the injectivity of which is reduced as a result of wastewater injection, a working agent bath is placed in the perforation interval in the amount of 4-6 m ³ during the time of dissolution of oil products deposited in the well and perforations from the wastewater. As a working agent, distillate is used. As a rule, technological exposure of the well in the bath mode up to 9 hours is enough. At the same time, a minimum injectivity of the distillate by the well appears. Selling distillate in the bottomhole zone of the well is carried out with wastewater in the pulse drainage mode. At the wellhead, the pressure is increased to 11-13 MPa, then the pressure is released to atmospheric. The number of such pulses is prescribed 30-50. As a rule, this results in injectivity of the well, sufficient for the injection of chemicals. A 3-8% hydrochloric acid solution is injected into the bottomhole zone in a volume of 20-40 m ³ . With insufficient injectivity, the hydrochloric acid solution, like the distillate, is forced into the bottomhole zone in the pulse drainage mode: increase the pressure on the mouth to 11-13 MPa, then release the pressure to atmospheric pressure. The number of such pulses, as with the distribution of distillate, is prescribed 30-50. After this, technological exposure is carried out for 2-3 hours, but not more than 4 hours. During the sale of hydrochloric acid solution and technological exposure, the sulfides and oxides of iron and other clogging deposits are destroyed. To remove reaction products, 20–40 m ^{3 of} wastewater is pumped and proceeds to further pump wastewater as a working agent in the development of an oil reservoir.

The result of applying the method is to increase the injectivity of the well.

Concrete example

The bottom-hole zone of the injection well is treated at a depth of 1200 m. The injectivity of the well is reduced as a result of the injection of waste water from an operating mode of 250 m ³ / day to zero. In the interval of perforation by circulation deliver 5 m ³ working agent - distillate. Spend technological exposure (bath) for 9 hours. There is a minimum injectivity of the distillate in the well of the order of 10 m ³ / day. Selling of the distillate into the bottomhole zone of the well is carried out with wastewater in the pulse drainage mode: at the wellhead, the pressure is increased to 12 MPa, then the pressure is released to atmospheric pressure. The number of such pulses is set equal to 40. A 5% hydrochloric acid solution in a volume of 30 m ^{3 is} forced into the bottomhole zone. The hydrochloric acid solution is forced into the bottomhole zone in the pulse drainage mode: increase the pressure at the mouth to 12 MPa, then release the pressure to atmospheric pressure. The number of such pulses is assigned equal to 40. After this, technological exposure is carried out for 3 hours. Pumped 40 m ^{3 of} waste water. The injectivity of the well is determined, which has become equal to 220 m ³ / day. Go to the injection of waste water and the development of oil deposits.

Application of the proposed method will increase the injectivity of the injection well.

Claims (1)

A method of treating the bottom-hole zone of an injection well, including displacing the working agent at pressure and holding technological exposure, characterized in that before selling the working agent they organize a bath of working agent - distillate in a volume of 4-6 m ³ in the perforation interval with technological exposure up to 9 hours, selling the working agent is carried out with wastewater in the pulse drainage mode: increasing the pressure at the mouth to 11-13 MPa - depressurizing, the number of pulses is prescribed 30-50, pushing a 3-8% solution of salt ki lots in a volume of 20-40 m ^3, exposure process is performed no more than 4 hours and pumped 20-40 m ³ wastewater.