Device and method for stabilizing annulus pressure of oil sleeve

Abstract

The invention discloses a device and method for stabilizing annulus pressure of an oil sleeve. The method comprises the following steps that the annulus pressure of the oil sleeve is balanced through the pressure difference which are formed between an intelligent pumping system and an intelligent pressure relief system and by superimposing the pressure of an annulus-protection-liquid liquid column, when the annulus pressure is too high, a pressure relief valve is automatically opened owing to pressure overload, and redundant liquid or gas in an annulus is exhausted; when the annulus pressure is not enough, a working pump automatically pumps annulus protection liquid to be injected in the annulus, so that the annulus pressure is supplied; and sampling for the annulus protection liquid of the oil sleeve is achieved through the working pump, performance changes of the annulus protection liquid are detected, and the annulus protection liquid in the oil sleeve annulus can be replaced timely. The method has the advantages that the installation and construction technology are simple and convenient, a set of independent, safe and intelligent control system is formed, the pressure in the oil sleeve annulus can be stabilized effectively, the independent, safe and intelligent control system can be used for the sampling and replacing for the annulus protection liquid of the oil sleeve, various safety technological operation and maintenance of an wellbore of an oil gas well is carried out conveniently, and production and other operation of the oil gas well are not influenced.

Description

technical field

[0001] The invention relates to the technical field of oil and gas well safety, in particular to a device for stabilizing the annular pressure of an oil casing, and also relates to a method based on the device. Background technique

[0002] Annulus protection fluid, as a working fluid for oil and gas wells, is widely used in the oil casing annulus. It can not only balance the pressure of the oil casing annulus, reduce the pressure between the tubing and the annulus, and relieve the casing head and packing pressure. The pressure on the device can be effectively protected against corrosion of the oil casing.

[0003] At present, with the increasing demand for oil and gas and the continuous deepening of exploration and development work, the downhole geological conditions and wellbore structure are becoming more and more complex, and the problem of abnormal annular pressure is becoming more and more prominent. On the one hand, for gas wells, under some abnormal ...

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