SU1647122A1 - Method of isolating perforation zones of casings - Google Patents

Abstract

The invention relates to the mining industry and can be used when pumping fluid into the open-cut intervals. The goal is to increase the frequency of disunity of perforations in oblique CTBPTIO. To do this, the cementing head is screwed onto the upper casing coupling (OK) installed in the drilled well and the lower self-sealing plug is lowered into the OK. Then the cement mortar is pumped into the well, forming a compensating bridge. A self-sealing plug of the PNC type is lowered into the OK and the cement rastior is pumped into the well, thereby establishing a working bridge. After this, the self-sealing plug is lowered into the OK and the marketing liquid is pumped into the well. The latter is pumped in the volume, which ensures installation of paired cement bridges over the zone and in the perforation zone. (L

Description

The invention relates to the mining industry and can be used in the discharge of fluid in the open-cut intervals, for example, to ensure safe mining operations.

The purpose of the invention is to increase the reliability of separation of perforation zones in an inclined shaft.

The method is carried out as follows.

From the day surface to the productive formation, the well is drilled, lined with pipes, plugged into the annulus, the casing and cement stone are perforated, and fluid is injected into the well, but the known parameters are used to calculate the parameters of the working and compensating bridges, and the length of the compensating bridge is determined from the relationship

Chmsh

- Scott + S

m,

where is the length of the compensating bridge, m;

Bverf is the length of the perforated zone of the casing; V is the volume of cement losses

the solution on the formation on the inner surface of the casing of the film during its transportation from the wellhead to the design mark-. 3.

O5

ND BO

ki, m

S casing cross-section area, m

Screwed onto the upper sleeve casing cementing head is lowered into the casing lower the self-yuschuyus stopper five- pas PSC is pumped into the well cement slurry (compensating bridge), is lowered into the casing tube the self-yuschuyus ipa PSC is pumped into the well cement slurry ( working bridge), put the upper self-sealing plug of the PNC type into the casing, with a sleeve of the rubber belt, a plug of the PVC type, pump the squeezing fluid into the well in the volume that ensures the installation of paired cement bridges over the zone and in the perforation zone.

Placed cuffs from the pro-elastic strap into the cavity of the upper self-sealing plug when pressing cement are pressed against the walls of the casing and thus prevent possible penetration: the fluids under the plug and prevent the rubber section of the plug from abrasion.

Claims (1)

The volume of the liquid can not be counted. After installing the paired cement bridges in the casing string, squeezing fluid is injected into the well up to the stop (a sharp increase with subsequent stabilization of the pressure at the wellhead). The lower self-sealing plug of the compensating bridge cannot be located outside the perforation zone due to the incompressibility of the fluid in the casing of the well. At the same time, the fluid located above the perforation zone and within it, when installing cement bridges, will be pressed to absorb the last. Invention Formula The method of separation of casing perforation zones, including screwing the casing head of the cementing head onto the upper sleeve, lowering the lower self-sealing plug into the casing, installing a working cement bridge by injecting the cement mortar, lowering the upper self-sealing plug into the casing, and placing the upper self-sealing plug into the casing of the cement mortar; rubberized belt, injection of squeezing fluid, characterized in that, in order to increase the reliability of separation of the perforation zones in the inclined shaft, before installing A cement bridge is additionally installed with a compensating bridge by injecting cement mortar and lowering the self-sealing plug uncoupling bridges. Editor A.Kschori O-if-i crucible I1.Chertov Ipvm p L.Oliynyk Proofreader L. Patay Order 1383  1ir- 5b5 VNIIPI Sovereign of the State Committee for Labor and Defense, KOMTUPI i according to inventions and operations under the State Committee for Science and Technology of the USSR 11303-, Moscow, No}), 4/3 Raushsk nab. Subscription