Formation test packer and method for formation test using same

Abstract

The invention relates to a packer for formation testing and a method for using the same for formation testing. The packer includes an upper joint, the upper end of the upper joint is provided with a tapered female thread, and the inner thread at the lower end of the upper joint is screwed with a downward Extended core tube, the lower end of the core tube is plugged into the upper port of the lower joint and sealed by an O-ring, the lower end of the lower joint is provided with a tapered male thread; the outer circumference of the core tube and the lower part of the upper joint are provided with a communication seal The bypass mechanism for the upper and lower liquid flow of the spacer, the setting mechanism is arranged under the bypass mechanism, the shear pin mechanism is arranged under the setting mechanism, and the transposition mechanism for controlling bypass and setting is arranged under the shear pin mechanism. When going downhole, the bypass is opened to connect the upper and lower annulus; when in place, the core pipe is rotated, the bypass is closed and set, the formation fluid enters the pipe string, and then the bypass is opened and unsealed, and the pipe string is lifted. The invention ensures that the straddling packer will not be set in advance during the drilling process, thereby effectively protecting the packer rubber cylinder and effectively improving the success rate of the straddling test.

Description

technical field [0001] The invention relates to an apparatus for downhole testing, in particular to a packer for formation testing; the invention also relates to a method for using the packer for formation testing for formation testing, which belongs to the technical field of oil and gas testing. Background technique [0002] In the process of oil exploration, oil, gas and water layers can be preliminarily determined through cuttings logging, gas logging, core analysis and electrical logging interpretation data, but they need to be verified by oil testing in the end. Formation testing, also known as drill string testing, is a key link in scientific oil testing. It plays an important role in determining reservoir productivity, fluidity, energy, and reservoir seepage characteristics and parameters, and can provide reliable data for further exploration and development of blocks. Detailed basis. [0003] The cased well spanning test is mainly used for cased wells that have been...

AI Technical Summary

Problems solved by technology

[0005] As a packer for downhole testing, the shear pin packer has the following problems due to its structure: 1. If the lower end of the tool is blocked or stuck during running in, or the ground operation is improper, the shear pin will be advanced The risk of shearing will cause the packer to be set in advance, causing the rubber sleeve to be in a state of compression and expansion during drilling, and the rubber sleeve will rub against the casing wall. When it reaches the predetermined depth, the shear pin packer rubber sleeve will be damaged. Cannot play an effective isolation role, making the cross-isolation test operation fail

At present, the success rate of cross-compartment testing at home and abroad is very low

2. After the tool is set normally, the shear pin traverses the middle of the packer. Due to the limitation of the shear pin, the full diameter cannot be achieved, and other operations cannot be performed within the tool diameter; 3. The tool itself is not equipped with a balance rubber cylinder , The function of lower pressure difference needs to be used in conjunction with other tools

However, after the ground experiment, it takes about 10T to set the seal for the first time, and it will be set when the pressure is 1-2T afterward, which does not meet the requirements for repeated use.

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