RU2224102C1 - Method for isolating water influxes or absorption areas in a well - Google Patents

Abstract

FIELD: petroleum extracting industry. SUBSTANCE: method includes consecutive pumping into the well of nepheline-based gel-forming material, separator and 14-16% water solution of hydrochloric acid. As gel-forming material dispersion of syenite alkali-aluminum concentrate in bearing fluid is used at volumetric relation of one to other of 1:(1.9-2.1) and at volumetric relation of said dispersion to said water solution of hydrochloric acid accordingly of (0.9-1.1):1. EFFECT: increased technological and practical effectiveness of isolating water influxes or absorption areas in a well. 1 ex

Description

The invention relates to the oil industry and may find application in the isolation of water inflows or absorption zones in a well.

A known method of developing oil fields, including injection through an injection well into the formation in the form of a rim of a gel-forming fluid based on nepheline, hydrochloric acid and water, forcing it into the formation with water, stopping the well for the period of gelation and starting the well for injection (RF Patent No. 2089723, cl E 21 B 43/22, publ. 1997.09.10).

The known method involves mixing the components of a gelling liquid before injection, which negatively affects the viability of the mixture and reduces the technological properties of the method.

Closest to the invention in technical essence is a method of impacting a carbonate pore-fractured reservoir by injecting into the formation through a well a gel-forming solution based on nepheline and hydrochloric acid, forcing fluid-oil, carrying out technological aging and injection of a 10-17% hydrochloric acid solution . In this case, isolation of water inflows or absorption zones occurs in the well (RF Patent No. 2171370, class E 21 B 43/22, publ. 2001.07.27 - prototype).

The known method involves the sequential injection of the components of the gelling material, which improves the technological properties of the method. However, the method is not technologically advanced due to the presence of a hardener (hydrochloric acid) in one of the components of the gelling material and is not effective enough to isolate water inflows or absorption zones in the well due to the weak reactivity of the main gelling component - nepheline.

The invention solves the problem of improving the manufacturability of the work and the efficiency of isolation of water inflows or absorption zones in the well.

In a method for isolating water inflows or absorption zones in a well, comprising sequentially injecting into the well a gelling material based on nepheline, a separator and an aqueous solution of hydrochloric acid of 14-16% concentration, a dispersion of syenite alumina alkali concentrate in a carrier fluid is used as said gelling material their volume ratio, respectively, 1: (1.9-2.1) and the volume ratio of the specified dispersion and the specified aqueous solution of hydrochloric acid, respectively (0.9-1.1): 1.

The features of the invention are

1) sequential injection into the well of a gelling material, a separator and an aqueous solution of hydrochloric acid;

2) use as a gelling material a dispersion of a syenite alumina alkali concentrate;

3) the same in the carrier fluid;

4) the same when the volume ratio of the dispersion of the concentrate syenite alumina alkaline and carrier fluid, respectively, 1: (1.9-2.1);

5) the use of an aqueous solution of hydrochloric acid of 14-16% concentration;

6) the volume ratio of the dispersion of the syenite alumina alkali concentrate in the carrier fluid and the aqueous hydrochloric acid solution, respectively (0.9-1.1): 1.

Sign 1 is common with the prototype, signs 2-6 are the hallmarks of the invention.

SUMMARY OF THE INVENTION

During the development of an oil reservoir, the produced oil is flooded due to the passage of the working agent through the most permeable zones of the reservoir. To reduce the water cut of oil, work is carried out to isolate water inflows or absorption zones in the well. Existing methods of insulation are not always distinguished by high manufacturability due to the danger of premature setting of the gel-forming composition and low quality of insulation due to the creation of an insufficiently strong gel. The proposed method solves the problem of improving the manufacturability and quality of insulation work. The problem is solved as follows.

When isolating water inflows or absorption zones, gelling material, a separator and an aqueous solution of hydrochloric acid of 14-16% concentration are sequentially pumped into the well. As a gel-forming material, a dispersion of syenite alumina alkali concentrate in a carrier fluid is used with a volume ratio of syenite alumina alkali concentrate and carrier fluid, respectively, 1: (1.9-2.1). The volume ratio of the dispersion of the syenite alumina alkali concentrate in the carrier fluid and the aqueous hydrochloric acid solution is set respectively (0.9-1.1): 1.

Syenite alumina alkali concentrate is obtained from apatite-nepheline ores. Available in accordance with TU 5726-047-00203938-97. The concentrate contains 75.0-80.0% of the pure nepheline mineral. It is used in the construction industry as a component in the manufacture of building materials, as well as in the glass industry and ceramics.

Specifications: appearance - crystalline powder of a dark gray color; the content of aluminum oxide is not less than 26.00%, the content of silicon oxide is not more than 46.00%, the content of sodium and potassium oxides is not less than 18.00%, the content of iron oxide is not more than 3.50%, humidity is 1, 00 ± 0.50%.

Mineralogical composition,%: apatite - 0.30-0.60, nepheline - 75.00-80.00, aegirine - 4.00-6.00, sphene - 0.40-0.70, microcline - 10.00 -14.00, titanomagnetite - 0.20-0.40, hydromica - 1.00-3.00, lepidomelan - 0.20-0.40.

The particle size of the used syenite alumina alkali concentrate is 0.07-0.16 mm.

As the carrier fluid, water or aqueous solutions, a hydrocarbon liquid, for example oil, etc. are used.

A hydrocarbon liquid, for example oil, is used as a separator.

The dispersion of the syenite alumina alkali concentrate has unlimited viability in the carrier fluid and retains it in reservoir conditions until the hydrochloric acid solution approaches. This determines high technological properties, i.e. high viability of the dispersion.

Upon contact with a solution of hydrochloric acid of 14-16% concentration, a sharp increase in viscosity occurs, setting and hardening of the syenite alumina alkali concentrate, formation of a strong gel and isolation of water inflows or absorption zones in the well. A concentration of 14-16% is optimal for the setting and hardening of the gelling material. The same can be said about the ratio of the dispersion and the aqueous solution of hydrochloric acid (0.9-1.1): 1.

An example of a specific implementation.

The bottom-hole zone is treated in an oil well in the perforation interval of 2360-2368 m. 2.5 m ^{3 of} dispersion of syenite alumina alkali concentrate in water (carrier fluid) is pumped into the perforation interval with a volume ratio of dispersion of syenite alumina alkali concentrate and water, respectively, 1: 2, 0.2 m ^{3 of} oil (separator) and 2.5 m ^{3 of a} 14% aqueous hydrochloric acid solution are pumped. Spend technological exposure for 2 hours and launch the well into operation. As a result of processing, the water cut of oil decreased from 99 to 64% while maintaining a flow rate of 50-60 m ³ / day.

Application of the proposed method will improve the manufacturability of the work and the efficiency of isolation of water inflows or absorption zones in the well.

Claims (1)

A method of isolating water inflows or absorption zones in a well, comprising sequentially injecting into the well a gel-forming material based on nepheline, a separator and an aqueous solution of hydrochloric acid of 14-16% concentration, characterized in that a dispersion of syenite alumina-alkaline concentrate in a liquid is used as said gel-forming material -carrier with a volume ratio of 1: (1.9-2.1), respectively, and a volume ratio of said dispersion and said aqueous hydrochloric acid solution, respectively (0.9-1.1): 1.