Gas-driven packer and packer setting method

Abstract

The invention relates to a gas-driven packer and a packer setting method. According to the method, gas is fed through a drill rod under pressure to drive a setting packer, one-time drilling midway test under a gas drilling condition is realized, a gas phase is replaced by an original liquid phase medium, well killing and midway test are carried out, and a liquid phase is replaced by a gas phase medium; and dry shaft return gas drilling is simplified into direct testing by directly entering the packer under pressure under a gas medium condition, and gas drilling is directly recovered after testing. The drilling-measuring-well completion efficiency is improved, water-sensitive stratum collapse and drilling tool jamming caused by a balling drum are avoided, reservoir pollution is reduced, the operation time and cost are saved, an exploratory well can be directly converted into a production well, and the exploration and development pace of an oil and gas well is accelerated.

Description

technical field [0001] The invention relates to a gas-driven packer and a packer setting method, which belong to the field of gas drilling midway testing. Background technique [0002] The midway test is a process measure used to determine the completion method for the oil and gas layers discovered during drilling or the target layer after drilling. The midway test can timely and accurately understand the specific conditions of the reservoir performance and the contained oil, gas and water production during the drilling process. [0003] Gas drilling technology is one of the most effective means to develop low permeability, low porosity and water sensitive oil and gas reservoirs. At present, gas drilling has been widely used in Xinjiang, Sichuan, Qinghai and other oil fields, which greatly improves the drilling speed and saves drilling costs. When oil and gas shows are encountered during gas drilling, it is necessary to conduct a midway test immediately to understand the p...

AI Technical Summary

Problems solved by technology

[0004] At present, the packers at home and abroad are all designed for the wellbore in the liquid phase medium condition, and cannot be set and work normally in the gas phase medium condition.

When gas drilling encounters a gas layer and a midway test is required, the working medium in the gas phase of the wellbore needs to be converted into a liquid phase. After the test is completed, the working fluid in the wellbore needs to be converted back into gas and the wellbore should be dried. The process is complicated and the construction period is long. Moreover, frequently changing the working medium of the wellbore will weaken the stability of the wellbore wall, aggravate the water sensitivity of the formation, and cause downhole complexities such as wellbore collapse and drill sticking.

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