RU1810516C - Method for control of tightness of flow string of injection well - Google Patents

Abstract

Usage: in the oil industry, in particular for monitoring the tightness of a production well string under conditions where the reservoir pressure is lower than hydrostatic. SUMMARY OF THE INVENTION: A steady-state vacuum is measured at the wellhead after a shutdown of injection, the leakage of a column is judged by a sharp change in the vacuum value compared to previous measurements. T ill.

Description

The alleged invention relates to the oil and gas industry, in particular, to timely detect the presence of water leakage to a third-party object through violation of the production string in conditions where the reservoir pressure is below hydrostatic.

The aim of the proposed method is to increase the reliability of the control at a hydrostatic pressure exceeding the reservoir.

The goal is achieved by measuring the established vacuum at the wellhead after stopping the injection, and the leakage of the column is judged by a sharp change in the value of the vacuum compared to previous measurements. .

The proposed method is implemented in the process of quarterly monitoring the injection of water and allows timely detection of wells with leaks in foreign objects through defects in production casing.

Execution example

To implement the proposed method, the wellhead is equipped with sealed valves 1, 2 by valve 3 (see drawing). With open valves 1, 2 and valve 3, without an exemplary vacuum gauge 4, the outlet 5 and the annulus 6 are flushed to remove stagnant water of increased density. With the appearance of clean water, shutter 2, valve 3, and then shutter 1 are closed alternately. An exemplary vacuum pressure gauge 4 is attached to valve 3 and after a certain time, after the vacuum has completely stabilized (1.5-2 hours), measure its value .

With a sealed production casing 7, the rarefaction value will not differ much from the value measured at the end of the previous quarter, while all injected water is absorbed by the injection object 8. In case of leakage of water into the foreign object 9 through defect 10, the rarefaction value will be significantly different and have a significantly lower value split

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n Charge compared to previous. In this case, the tubing 11 rises, the location of the detected leak through the defect of the production casing 10 is determined, followed by its isolation.

Technical and economic efficiency from the use of the proposed method for monitoring the tightness of the production casing of an injection well is ensured by:

- timely detection of water leakage into a foreign object;

- elimination of the costs associated with conducting routine research for the audit of the production string for tightness by the method of thermometry;

- increasing the information content control over the injection of water into the developed object ..

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The method has found wide application in the Bars-Gelmes field, where the current reservoir pressure is much lower than hydrostatic.

Claims (1)

SUMMARY OF THE INVENTION A method for monitoring the tightness of a production well casing string, which includes periodic measurement of formation pressure, which changes the status of the production casing string, characterized in that, in order to increase the reliability of the test, when the hydrostatic pressure exceeds the reservoir pressure, measurement is performed after stopping the injection. the wellhead of the established discharge, and the leakage of the column is judged by a sharp change in the amount of rarefaction compared to previous results measurements. 4