SU1758206A1 - Method of checking operation of hydraulic packer - Google Patents

Abstract

Field of use: oil and gas well mounting techniques using hydraulic casing packers. Summary of the Invention: Determine the pressure of the full opening of the packer outside the well and determine the amount of decrease in injection pressure when opening the packer in the well, then calculate the inverse ratio these values, pumping packer at the values of the latter in the range of 0.9-1.6.

Description

The invention relates to the technology of mounting oil and gas wells, and in particular to methods of controlling the operation of hydraulic packers installed on the columns of pipes run down the well, and can be used in the technology of mounting oil and gas wells.

A known method of controlling the operation of a hydraulic packer is that inside the valve device of the packer, floating elements are placed in a special annular cavity, made in the form of containers filled with a light liquid. When the valve device is triggered and the packer sealing element is filled with the squeezing fluid, the annular cavity opens, the floating elements come out of it and rise in the squeezing fluid that fills the pipe string to the wellhead. The occurrence of floating elements at the mouth indicates the normal operation of the packer valve device.

A known method for controlling the operation of the annular hydraulic packer, according to which the operation of the packer (or packers) is controlled by withdrawing the estimated volume of fluid from the casing to fill this column. In this method of control, the packing element is used to displace the sealing element of the packer. liquid. In this case, the squeeze fluid is displaced from the casing with a packing fluid, which in turn is displaced from the annular space into the column by the action of the packer in the fluid and the opening element.

There is also known a method for controlling the operation of a hydraulic packer, in which, as a signal to open the sealing element of the packer, a decrease in fluid pressure in the deflated

X |

01

Yu

D well pipes connected to the packer.

The disadvantage of this control method is the low reliability of the packer, which is caused by the absence of an accurate measurement of the magnitude of the decrease in pressure and the use of measurement results to control the quality of the operation of the packer.

The aim of the invention is to increase the reliability of hacking by providing a TQunois installation of a hacker in a predetermined interval.

The goal is achieved by supplying the working fluid under the injection pressure to the cavity of the packer lowered into the well and registering the decrease in this pressure when the packer operates, determining the pressure of the full opening of the packer outside the well and determining the amount of reduction in the pressure of the packer when opening the packer , then the inverse ratio of the indicated values is calculated, and the packer is pumped at the values of the latter in the range of 0.9-1.6.

The essence of the invention is as follows.

The total opening pressure of the packer outside the well is determined, which can be performed by calculation. The formula for determining this pressure DDR is derived from the law of compressibility of liquids AV / 3 V-DRE (1

and expressing the internal volume of the packer sealing element in a fully opened state in a borehole of diameter D:

yy

AV ij (, (2)

where AV is the change in the volume of fluid in the pipe string, m;

/ J - compressibility factor of the liquid, MPa 1;

V is the internal volume of the column, m,

DRT - change in fluid pressure, MPa;

D is the nominal diameter of the well bore in the installation area of the packer, m;

6- wall thickness of the packer sealing sleeve, m;

d is the outer diameter of the packer sealing sleeve in an undisclosed state, m;

I - length of the packer sealing sleeve, m;

Solving equation (1) for DRT, we get

DRT

AV W

(3)

Substituting in the formula (3) instead of AV 5 its expression (2), we obtain the formula for determining DDA:

Drt

p (P-2 P2-s123

(four)

five

0

0

After the descent and installation of the packer at a predetermined depth at the end of the cementing, the pressure is increased by injecting fluid into the pipe string until the stop moment is fixed. There is a disclosure valve assembly packer. At the same time, the internal cavity of the packer sealing sleeve is connected to the pipe string, and the liquid enters the cavity of the sealant, expands it and presses tightly against the borehole wall. As a result, pressure in the pipe string decreases, after which the specified pressure remains constant. The decrease in pressure of the DP is measured using an exemplary manometer installed at the wellhead. Then, the inverse ratio DTH and Afy is calculated. Packing is completed when the reliability criterion is set to DR, / DRT within 0.9-1.6. These limits were found experimentally.

An example (relates to well No. 743 of the Fedorovskoye field of the Tyumen region) The necessary parameters of the well and drilling fluid pumped into the casing string are as follows: D 214 mm; d 168.3 mm (packer ПГП-158); 5 8 mm; I - 1.18 m; ft 4.3-10 MPa;

V 44.2 m °.

First, it is determined if the formula is

(four):

45

Drt 1 (0.214 -0.016) 2 - 0.16832 7G 1.18

4 4.3 10

442

-0,503 MPa.

After descending and installing the packer in the well at a predetermined depth, the drilling fluid was pumped into the casing under overpressure until the stop moment was fixed. At a pressure of 15 MPa, there was an abrupt decrease in injection pressure of an AR value of 0.55 MPa, which was measured using an exemplary manometer installed on a cement head. This decrease in pressure indicated that the packer was triggered.

Calculate the reliability criterion / DRT, which turned out to be equal to AR 0.55 ЗГРТ 0,503

1.09.

LR Since the criterion d ru was found

within the limits of 0.9-1.6, the packing was completed (with a high degree of reliability, which was confirmed during the well operation period).

d

15

Claims (1)

Claims The method of controlling the operation of a hydraulic packer, including the flow into the cavity of a packer, lowered into the well, of a working fluid under overpressure injection and recording a decrease in this pressure when the packer operates, is such that, in order to improve the reliability of the packer by ensuring accurate setting the packer at a predetermined interval, determine the total opening pressure nsxeps outside the well and the amount of injection pressure decreasing when opening the packer in the well, and then calculate the inverse the ratio of these values, and the packer end when the value of the latter in the range of 0.9-1.6.