SU874975A1 - Method of stopping a well - Google Patents

Description

(54) METHOD OF HEARING SQUAH

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The invention relates to the oil industry, in particular, to methods for preparing a well for repair by killing a well with a pumping fluid followed by the development of a well, and can also be used for killing a gas well.

There is a well killing method that involves injection of a three-phase foam and a volume of mud into the well, excluding overflow of foam, in which the injection of foam and mud is performed with a time gap sufficient to warm up the foam to layer temperature l.

The disadvantage of this method is the difficulty of implementation and the need to use certain components.

There is a known method of plugging a well with an injecting fluid with pre-injection into the bottomhole zone of a blocking fluid 23

The disadvantage of this method is the low development efficiency of the well after killing,

The purpose of the invention is to increase the efficiency of well completion after plugging with an aqueous solution of inorganic salts.

This goal is achieved by the fact that, in the method of killing a well with preliminary injection into the blocking zone of the blocking fluid, micelle solution is injected as a blocking fluid.

The radius of treatment of the bottomhole zone with a micelle solution should be 0.1–5 m, while 0.1 m is taken at low permeability of the formation to 50 md or less. A treatment radius of 5 m is assumed for highly permeable formations: 60 ppm or more.

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Claims (1)

The volume of micelle solution required for these studies is determined by the formula V.p. JTR hm, where R is the wellbore zone processing radius, m h is the reservoir thickness, η is porosity,%. The radius of the bottomhole zone treatment that depends on the reservoir properties of the layer determines the volume of the micelle solutions, Micellar The solutions are ultra-microfine colloidal systems consisting of hydrocarbon liquids and water, stabilized by a mixture of surfactants. These solutions are characterized by extremely low interfacial tension at the interface with both oil and water, h and the capacity of the high oil and water injection capacity of micellar solutions. This property of micellar solutions is used in the implementation of the proposed method of well killing. The method is carried out as follows. The volume of micellar solution calculated by the above formula is pumped into the well. In laboratory conditions, the composition of the mid-body solution for the geological and physical conditions of a specific field is selected; Requirements for the selection of the micelle solution are as follows; a) the solution should be stable at reservoir temperature; b) the solution should provide low interfacial tensions at the interface with oil and water to the formation fluids. After pumping the required volume of micelle solution, they start filling the well with drilling fluid, using either high-density formation water or calcium chloride solution. Having balanced the reservoir pressure of the fluid in the wellbore, they start the repair work. After the completion of the repair work, they cause the fluid to flow from the well by reducing the pressure of the liquid column in the well. The pressure on the well is often reduced or successively by replacing the well fluid in a well with a liquid or gas-liquid mixture of lesser density or lowering the fluid level in the well. Calling fluid inflow to the bottom of the well means calling filtration of formation fluids and liquids saturating the well bottom zone. in the well bottom zone, the following zones of saturating liquids (in terms of distance from the well bottom) occur: the zone of the penetrating drilling fluid in the formation, the injected zone the micelle solution, the zone of oil and water saturating the reservoir, and the resumption of operation of the well, the reservoir oil and water, due to the fry of interfacial tensions at the border with the micellar solution, completely displace the micellar solution, which in turn, by the same the reason is completely laundering components of the injector fluid that have penetrated into the bottomhole formation zone. As a result, not only the permeability of the bottomhole zone is restored to the value that it was characterized before the repair work, but also increased permeability. An example of the proposed method for isolating the bottomhole formation zone in the Romashchkinskoye field, Productive reservoir parameters: Average depth, m1800 Effective oil saturation of the reservoir, m Effective porosity,% Plast temperature, C Permeability of the reservoir, MD The following micelles were selected for the Romashkinskoye field conditions composition, weight,%; Sodium sulfonate oil (24%) 31 Isopropyl alcohol 1 Oil V Water 60 The interfacial tension of this micellar solution at the interface with both oil and water is 0– DN / cm. In the study of the proposed micellar solution on samples of productive sandstone, the degree of displacement of both oil and test fluid was 100%, and the permeability of the sample increased by 23%, indicating a high efficiency of the solution. To ensure the radius, the treatment of the bottomhole formation zone of 5, 2 m in size, will require 28 m of micellar solution. The calculation was made according to the formula given earlier 3.34 X 2 X JO X 0.22 28 (m) The prepared micellar solution is pumped into the well, Following the micelle solution, calcium chloride solution is pumped in; predestined 33 m. Then proceed to repair work. After completion of repair work, the well is developed, the flow of fluid from the reservoir is eliminated by replacing the calcium chloride solution in the well with fresh water. and water, due to the small values of interfacial solutions at the border with the micelle solution, completely displaces the micelles from the bottomhole zone, which completely displaces the components of the lateral 5 well from the bottomhole zone. fluid penetrated into the reservoir at the wellhead jamming. Claims The method of well killing with an injecting fluid with pre-injection of a blocking fluid into the bottomhole zone, characterized in that, in order to increase the well development efficiency after dying with an aqueous solution of inorganic salts, micelle solution is injected as a blocking fluid. Sources of information taken into account in the examination, 1. The author's certificate of the USSR in application No. 2414782 / 22-03, cl. E 2 B 33/10, 1976,. 2, Voronov B, N, et al., Killing and development of wells. Under conditions of reduced Reservoir pressures. - Gas Industry, 1972, No. 8, p. 5 - 8