RU2286447C2 - Method for water influx isolation in horizontal producing well bore - Google Patents

Abstract

FIELD: oil and gas industry, particularly to isolate water influx in producing well bores.

SUBSTANCE: method involves injecting viscous oil with fillers soluble in light oil or in acid in well to create preventive filtering layer; injecting polymer solution into bottomhole formation area; displacing the polymer solution with water; shutting-down well for time necessary for polymer solution hardening. Viscous oil fillers have particle dimensions exceeding dimensions of pores and channels in oil-bearing part of horizontal bore, but are less than channel dimensions at water influx zone. The polymeric composition includes hydrophobic polymeric plugging composition, which is initially displaced with oil and then with water. Then hardened polymeric plugging composition is drilled and acid, light oil, diesel fuel or distillate is injected. In the case of high water influx interval injectivity hydrophobic plugging composition is injected in horizontal bore after preventive filtering layer creation. The hydrophobic plugging composition is based on hydrocarbon fluid mixed with hydrophilic powder material or mixture of hydrophobic plugging composition with hydrophobic polymeric plugging composition is used.

EFFECT: increased efficiency along with retaining of oil output from oil-bearing interval.

2 cl, 1 ex

Description

The invention relates to the oil industry and is intended to isolate water inflows in horizontal trunks of production wells.

A known method of processing and isolating the bottom-hole zone of wells, including the injection of an insulating composition based on PAA and acid [1]. The method is ineffective in horizontal wells, primarily due to the fact that it is suitable for use when the interval of water inflow is known, and also because of the low blocking ability of PAA, which is "sewn up" in the well, being squeezed into the barrel section.

There is another way to isolate water inflows in horizontal trunks [2].

Fundamentally, the method, which is the closest analogue, is presented in the following form. The method includes injecting a polymer and acid solution into the bottomhole zone. The method is intended to isolate water inflow when its interval is known.

When watering a horizontal trunk, it is filled with water. The call of fluid inflow by lowering the pressure in the well makes it impossible to determine from which interval the oil comes from, from which water, because the intensity of water occurrence in this case is much greater than oil manifestation. This is the main disadvantage of the method, because it is not suitable for use when the interval of water inflow is not known where it is located.

Since there are currently no methods for determining the intervals of water inflow in a horizontal wellbore of a waterlogged well, there is a problem of conducting insulating work in a horizontal well with the creation of a method of selective isolation in which the injected mixture mainly falls into the interval of water inflow with minimal penetration of it into the oil-saturated part of the horizontal wellbore.

The proposed invention solves the problem of isolating the water inflow zone in a horizontal wellbore held in an oil reservoir with inviscid oils, represented by medium and coarse-grained rocks. Moreover, for cases when it is not known in which place of the horizontal trunk a water inflow zone has arisen.

The technical result is an increase in the efficiency of insulation work while maintaining the productivity of the oil-containing interval.

In the method of isolating water inflows in a horizontal well of producing wells, including injecting a polymer solution into the bottomhole zone, pumping a polymer solution with water, stopping the well while the polymer solution is curing, viscous oil with fillers soluble in the polymer is injected into the well before the polymer solution is injected into the well; light oil or acid, the particle size of which is larger than the pore and channel size in the oil-bearing part of the horizontal wellbore, but smaller than the channel size in the water zone ritoka, the polymer solution using a hydrophobic polymeric backfill composition GPTS, carried prodavku GPTS first oil, then with water, cured GPTS drilled out, pumped acid or light oil, or diesel, or distillate.

At high injectivity in the interval of water inflow into the horizontal well after creating a preventive filtration layer, a hydrophobic cementing composition of hydraulic structures based on a hydrocarbon liquid with hydrophilic powder material or a mixture of these hydraulic structures and hydraulic structures are pumped into it.

As GPTS can be used, for example, a composition containing in weight. parts: prepolymer FP-65-2 100, hydrocarbon liquid 50-100, water 2-3, filler 1-10, hardening accelerator UP 606/2 0.1-0.2. As GPS, for example, a composition containing in weight may be used. parts: cement 100, oil 50, inert filler 5, anionic flocculant Praestol 0.1-0.2, water-swelling polymer AK-639 0.1.

The essence of the method is as follows. Before the tampon composition is flooded into the horizontal horizontal well, viscous oil with oil or acid-soluble fillers is pumped into it to create a protective preventive filtration layer on the surface of the oil-containing interval, which ensures that the HPTC (plug composition) can enter only large water-drained channels in the water inflow interval. There GPTS is cured.

After that, it is drilled and development of the well. In case of insufficient flow rate, the barrel is processed by injection of light oil or diesel fuel or distillate. At the same time, the preventive filtering layer of viscous oil with fillers is destroyed on the surface of oil-containing rocks. Oil production without water is restored.

With a high injectivity of the water inflow zone, a hydrophobic cementing composition of hydraulic structures based on hydrocarbon liquid with hydrophilic powder material or a mixture of these hydraulic structures and hydraulic structures is pumped into the well. As a hydrophilic powder material (powdery insulating material), cement, a water-swellable polymer, and the like can be used. Pumping hydraulic structures along a horizontal trunk with a filter cake from a viscoplastic fluid does not cause difficulties. The manifestation of the clogging ability of the hydraulic structures is observed when it enters the water inflow zone, where the hydrocarbon liquid on which the powder is shut off is separated and the powdery insulating material interacts with water.

An example of execution in the field.

At the first stage of work, hydrodynamic studies are carried out in the well, and the presence of large channels is determined during data processing. After that, viscous oil with oil-soluble fillers is pumped into the well in order to create a preventive filtration layer in the range of oil-containing rocks. If, at the same time, the injection pressure at the wellhead has not increased, then a buffer of viscous oil and GPTS with large fillers is pumped into the well. Selling is carried out first with oil to fill the horizontal trunk, then with water. The well stops at the time of curing of the GPTS.

The technological novelty and effectiveness of the proposed composition is to ensure isolation of water inflow intervals with large channels - cracks while maintaining oil inflow from the oil-containing interval of the horizontal trunk.

Information sources

1. A.S. USSR, No. 836340, class E 21 B 43/27, 1981

2. RF patent No. 2101484, cl. E 21 In 43/27, 1997 (the closest analogue).

Claims (2)

1. A method of isolating water inflows in a horizontal well of production wells, including injecting a polymer solution into the bottomhole zone, pumping a polymer solution with water, stopping the well for the duration of the curing of the polymer solution, characterized in that viscous oil is pumped into the well before the polymer solution is injected to create a preventive filter layer with fillers soluble in light oil or acid, the particle size of which is larger than the size of pores and channels in the oil-bearing part of the horizontal wellbore, but smaller than in the channels in the water inflow zone, a hydrophobic polymer grouting composition of GPTS is used as a polymer solution, GPTS is sold first with oil, then with water, cured GPTS is drilled, acid, or light oil, or diesel fuel, or distillate are pumped. 2. The method of isolating water inflows according to claim 1, characterized in that, at high injectivity in the interval of water inflow, a hydrophobic grouting composition of hydraulic structures based on a hydrocarbon liquid with hydrophilic powder material or a mixture of these hydraulic structures and hydraulic structures are pumped into a horizontal well after creating a preventive filter layer.