SU1331999A1 - Method of dividing successive fluid flows in oil and gas wells - Google Patents

Abstract

The invention advances cementing of casing strings in the mining industry and makes it possible to increase the efficiency of flow separation by maintaining the integrity of the pack of the visco-elastic separator (BUR). The method involves pumping through pipes and an annular space for a borer, for the preparation of which the dimensional capacity of the cementing unit is used (3 m). The pumping is carried out with the maximum allowable; from the point of view of preserving the continuity of BUR, the speed determined by the ratio V (DC-D) p-, where 1 is the height i of the VUR column in the annular space of the well, m; 6 - the value of the first difference of the normal stresses of VUR, Pa; D {. - diameter of the well, m; D is the outer diameter of the pipe string, m; p is the density of the VUR, kg / m; Vy is the criterion that determines the ratio of the elastic and inertial forces of the power steering device, 1 450 450-490. with (O CO with so with so

Description

The invention relates to the field of mining, more precisely to the drilling of oil and gas wells, in particular to methods of cementing casing columns in complex geological conditions that predetermine the possibility of inter-layer flows through channels formed due to incomplete displacement of drilling mud, and to methods for replacing fluids in the well at the opening of the productive formation, perforation, plugging, call-in, etc.

The purpose of the invention is to increase the efficiency of the flow separation by maintaining the continuity of the bundle in the elastic elongator (BUR),

VUR is pumped through the well with a speed determined from the ratio

 U

(D ;-D)

1 height of the drill column in the annular space of the well,

m;

6 - the value of the first difference of the normal voltage i-VUR, Pa;

D. - borehole diameter, m; D is the outer diameter of the pipe string, m;

 DENSITY WUR, KG / M

Example. Cementation of the production string in the well is performed; The casing column with a diameter of Oz146 and a length of 2,200 mm is lowered into a well drilled with a chisel of 0.2159 m. The design height of the cement rise is 500 m. The goal of increasing the separation efficiency of sequential flows of drilling and cement is the criterion that determines the ratio of elastic and inertial

the forces of the RDD, equal to 450-490, 35 thieves applied the BUR, prepared by

based on the impurity of the bentonite suspension of 15% concentration and 1.0% aqueous solution of polyacrylamide, taken in a ratio of 3: 1. For contrast to the known methods of separating HQTOKOB fluids in wells, using of compositions, in particular when cementing casing strings, the proposed method for managing RMS uses dimensional measures to achieve greater efficiency in RCC operation, because when using RMS by known methods, under certain conditions, there is a loss of its continuity and, as a result, completely There is a separation ability

The method is carried out following 1m. in a way.

In the well prepared for cementing, the difference in the diameters of the borehole and casing string (Dg-D) is determined. In accordance with the procedure known from the known methods, a sample of the drill was prepared using materials (water, f-chemicals, etc.) that will be used in the cementing of this squash. Determine

density (p) separator. One method, for example, is to measure

the barus effect upon expiration from the capillary determines the value of the first difference of the normal stresses of BUR S (d). Then set the height of the column BUR in the annular space (1). A value of 1 is determined by the volume of the container used by the dpd preparation method. The maximum permissible, from the point of view of maintaining the continuity of BUR, the velocity of the movement of liquids in the annular space is determined from the ratio

V

Id

(Dc-D) p.V

The continuity of the VUR and the safety of work will be ensured if the inequality holds where Vg is the maximum velocity of the fluid at which hydraulic fracturing is not allowed. Otherwise, either the value 1 is changed or another BUR composition is prepared that has the required values. y and r.

Example. Cementation of the production string in the well is performed; Casing column diameter Oz146 and a length of 2200 mm lowered into the well, drilled with a bit 0.2159 m. The design height of cement lifting is 500 m, G is aimed at increasing the efficiency of separation of sequential flows of drilling and cement.

bone cementing unit (3 m). Under these conditions, the following parameters are taken as the source data:, 0699 m, r 1120 kg / m, Pa,, 50 m / s, m. Then, as far as the continuity of the VUR is maintained, the velocity of the fluids in the annulus is

, 49-l, 43 m / s.

Finally take the average speed, 46 m / s. Obviously, in this case, the inequality

50

55 is executed. Thus, the preservation of the continuity of airborne drilling and the safety of work can be achieved if the velocity of the fluids does not exceed 1.46 m / s. WITH

In order to fulfill this condition, the well cementing is carried out as follows.

Using a cementing unit, 3 m of BUR is pumped into the column. In this case, the height of the posture post airborne posture after exit is 151 m.

The shutter and pumped into the column 1I m of cement with a pump capacity of 10 l / s. During this operation, the VUR is driven in the column at a speed of 0.75 m / s.

The squeeze plug was started and 25 m of squeezing liquid was pumped into the column with a capacity of 10–15 l / s. In this case, in the pipe string, the VUR moves at a speed of 0.75-1.13 m / s, and in the annulus space - at a speed of 0.60-0.90 m / s

1.4 m of pumping fluid is pumped with a capacity of 2-5 l / s to obtain a stop pressure.

Thus, during the entire process of cementing, the speed of movement of the fluids does not exceed a certain limit, which ensures the preservation of the integrity of BUR.

The results of acoustic cement measurement show that the ratio of the density of contact between the cement stone and the bounding surfaces is 89%. During the development of the well, the inflow of bevodic nephaste was obtained. Compose 5 -E. Molchanova Editor N. Tupitsa Tehred A. Kravchuk

3779./29

Circulation 532 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

about the absence of elastic and inertial reservoir flows.

Claims (1)

Invention Formula The method of separation of consecutive flows of liquids in oil and gas wells by pumping the zooelastic separator through pipes and annular space, is due to the fact that, in order to increase the efficiency of the separation of streams by preserving the continuity of the pack in the viscoelastic separator, speed determined from the ratio  Dj-dj / v; where 1 is the height of the column in the zoelastic separator in the annular space of the well, m; & - the value of the first difference; normal stresses in the echo elastic separator. Pa; DC - borehole diameter, m; D is the outer diameter of the pipe string, m; p is the density in the eco-elastic separator, Vy is the criterion that determines the ratio of elastic and inertial forces in the elastic elastic separator, equal to 450-490. Proofreader L .Patay