Sample sucking and discharging device applied to well logging instrument during drilling

Abstract

The invention discloses a sample sucking and discharging device applied to a well logging instrument during drilling. A pumping module which is currently applied to a formation tester cannot conduct pressure reduction operation on fluid under a shaft. According to the sample sucking and discharging device, a plunger type cylinder is installed at the lower end of a piston cylinder; the piston cylinder is divided into a head port and a rod port through an integral piston; a piston rod of the integral piston stretches into the plunger type cylinder, an inner cavity of the plunger type cylinder serves as a sample chamber, and a sample runner is formed in the bottom of the sample chamber; a bearing electric connector penetrates through the top of the piston cylinder; a displacement sensor penetrates through the bottom of the piston cylinder and is connected with the bearing electric connector; a guide rod of the displacement sensor stretches into the integral piston; the piston cylinder and the plunger type cylinder are sleeved with a pressure-resistant drum, the top end of the pressure-resistant drum is in threaded connection with an upper thread in clearance fit with an upper short section connector, and the bottom end of the pressure-resistant drum is in threaded connection with a lower thread in clearance fit with a lower short section connector; and the piston cylinder is fixed to the plunger type cylinder. The sample sucking and discharging device is applied to the well logging instrument during drilling and can work in a small space under the shaft.

Description

technical field [0001] The invention belongs to the field of oil and gas exploration and development, and in particular relates to a sampling device used in a logging-while-drilling instrument and working in a narrow space downhole. Background technique [0002] During the downhole gas detection process, the LWD tool needs to pump the fluid in the wellbore into the sample chamber inside the tool, and depressurize it to precipitate the hydrocarbon gas dissolved in the fluid. After the detection system in the instrument completes the hydrocarbon gas detection, the instrument needs to discharge the fluid back into the wellbore. [0003] At present, the pumping module used in the formation tester can pump the fluid in the formation into the instrument, and can discharge the fluid from the instrument to the wellbore, but it cannot depressurize the fluid downhole. Contents of the invention [0004] In order to solve the above problems, the present invention provides a sampling ...

AI Technical Summary

Problems solved by technology

[0003] At present, the pumping module used in the formation tester can pump the fluid in the formation into the instrument, and can discharge the fluid from the instrument to the wellbore, but it cannot depressurize the fluid downhole

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