Packer for formation testing and method for performing formation testing by adopting packer

Abstract

The invention relates to a packer for formation testing and a method for performing formation testing by adopting the packer. The packer comprises an upper joint, wherein a conical female thread is formed in the upper end of the upper joint, a core pipe extending downwards is screwed in an internal thread in the lower end of the upper joint, and the lower end of the core pipe is inserted into an upper port of a lower joint and is sealed through an O-shaped ring; a conical male thread is formed in the lower end of the lower joint; and a bypass mechanism capable of communicating upper liquid flow and lower liquid flow of the packer is arranged on the periphery of the core pipe and below the upper joint, a setting mechanism is arranged below the bypass mechanism, a shear pin mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the shear pin mechanism. During well descending, the bypass is opened to communicate upper and lower annuluses, after in place, the core pipe is rotated, the bypass is closed, setting is performed, stratum fluid enters a string, then the bypass is opened, unsetting is performed, andthe string is lifted. In the drilling process, it is ensured that the straddle packer cannot be set in advance, so that packer rubber sleeves are effectively protected, and the straddle test successrate is practically increased.

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.

Images