SU1448032A1 - Method of killing a gushing well - Google Patents

Abstract

The invention relates to the oil and gas industry and makes it possible to increase the effectiveness of the killing of the flowing wells. In the process of the Gloujuni, a string of pipes with a fitting element providing local resistance is lowered into the well. Install the punching element at a distance from the bottom of the pipe string, which is determined from the expression 1H1p (,) / / Gu_H | (where 1 is the distance from the shoe (bottom) of the pipe string, m; Dr - depression to the formation, IlaJ well flow rate by reservoir fluid, m / s, Yar - killing fluid flow at killing, m / s, g - acceleration of free fall, m / s; pp, p - density of fluid and fluid, leveling, kg / m. Pressure before the fitting the element is forced up to the value of the saturation fluid pressure of the gas by gas. 1 Cp ff. and S l

Description

4 00

WITH

Yu

The invention relates to the oil and gas industry and can be used in the killing of flowing wells.

The purpose of the invention is to increase the efficiency of the process.

The method is carried out as follows.

Determine the distance 1 from the pipe string shoe, on which it is necessary to establish local resistance, from the ratio reflecting the condition for reducing the depression to the formation to zero.

de 1 DR

q

1 BGN (,

g q (pp-p) —the distance from the shoe (JF Yarza) of the pipe string, m; Depressed on the reservoir. Pa, well flow rate in reservoir fluid, plugging fluid flow during plugging, m / s1

g - free fall acceleration,

density of reservoir fluid and damping fluids, respectively, kg / m.

Before descending the column of pipes under pressure at a distance of 1 from the shoe, local resistance is established in the form of a sub, washer, etc., which raises the pressure in front of it above the pressure of the formation fluid in gas. Then, the string of pipes is lowered into the well, and the killing is performed by pumping the plugging fluid with a pp density at a flow rate q while simultaneously studying the outgoing flow.

As a result of increasing the pressure to the saturation pressure, a single-phase liquid flow occurs. The density of the medium in the stream increases dramatically. The gas-liquid mixture has a low density (for example, for oil from the Tengiz field, the density of the mixture in a gas-liquid stream is approximately 3 kg / m, and the density of formation oil is 640 kg / m). The increase in the density of the medium causes additional repression on the formation. In addition, the gas – liquid mixture rate is much higher than the reservoir oil. 3fo follows the mass conservation law:

U48032

de

RF "RsmPOV .M-S,

(one)

H

and V ... density of fluid and gas-liquid mixture, respectively, kg / m; fluid velocity and gas-liquid mixture

respectively,

S m / s;

2

The decrease in the flow rate as a result of increasing the saturation pressure has the most significant effect on the removal of the kill fluid. The slower the flow rate, the greater the back pressure on the reservoir due to the accumulation of the enhanced kill fluid in the annulus. Thus, with an increase in pressure above the pressure of a pressure, there is a significant decrease in the flow rate and at the same time its density increases. The effect of these factors on the effectiveness of the killing process follows from formulas (2) and (3) below.

The gusher well gus is terminated when there is no pressure differential between the reservoir pressure and the well pressure, i.e. in the absence of depression in the reservoir. Reducing the depression to the reservoir to zero is accomplished by increasing the specific gravity of the mixture of formation fluid and plugging solution in the annulus. The increase in specific gravity is determined by the dependence for the flow of two-phase media:

one

l e U2ia3Li a Lai p (2 P «« q + P „

R

Where

ROM g

 f

mixture density, kg / m, free fall acceleration equal to 9.81, respectively, the density of the fluid and solution, well flow rate for the plastic fluid, m / CV q - flow rate of the killing fluid

when downloading, m / s. Therefore, the condition for reducing the depression or stopping the spouting is to replace the fluid with the blend in the zone, where d, the pressure is higher than the saturation pressure.

31448032

the zero is equal to the increase in the specific injection of the killing fluid through the pipe string in the well while simultaneously forming the outgoing flow.

sa in the annulus: (ps-p,)), (3)

where 1 is the distance from the shoe (bottom) of the pipe string, m; & p - depression on the reservoir, Pa, hence the value of 1 is equal to

Claims (2)

1. A method of plugging a spouting well 10, including lowering a pipe string under pressure and injecting a plugging fluid into a lowered string of pipes with upstream flow testing by installing local resistance, characterized in that, in order to increase the process efficiency, local resistance is set at a distance from the bottom of the pipe string, determined from the ratio : (four) AEli2 l 3.) 8 qp-Cpf-p) Example. A 4000,000 m deep well was jammed. The depth of the possible descent of the pipe string is 3000 m. The inside diameter of the casing in the well is 0.22 m. The density of the formation fluid is p, 640 kg / m. The reservoir pressure is p 80.0 MPa. The flow rate of the well in the reservoir fluid is equal to. Tl 0.05. A solution with a density of 2100 kg / m was used as a kill fluid. The flow rate of the kill fluid during injection is equal to 0.10 Depression on the layer of equal p „- Pjeg 80.0-70.0 10 MPa 1040 Pa. Substituting the above data in the formula 1 A () g-qp (- (Oi25 j: OilQU 1000 Gm  9, 10- (2100-640) - " determine the desired value of 1. Then, on the outer side of the pipe string, equal to 127 mm, at a distance of 1000 m from the shoe, the pipe string established local resistance in the form of a washer, lowered the pipe string into the well, and made a killing by Invention Formula 1. A method of plugging a flowing well, including lowering a pipe string under pressure and injecting a plugging fluid into a flat string of pipes with upstream flow testing by installing local resistance, characterized in that, in order to increase process efficiency, local resistance is set at a distance from the bottom pipe columns determined from the ratio (q, + Чр) Ч (, (рр-р, р) where 1 is the distance from the shoe (bottom) of the pipe string, m, ip is the depression to the formation. Pa; Yaa - well flow rate according to reservoir fluid, m / s; q - liquid consumption during jamming, m / s; g - free fall acceleration, m / s J RF PP of the density of reservoir oil and damping liquid, respectively, kg / m, wherein the pressure before the local resistance is increased to the value of the saturation fluid pressure of the formation gas. 2. Method POP.1, characterized in that a stepped pipe string is installed as local resistance.