A shale gas and core pressure-holding sealed sampler

Abstract

The invention discloses a pressure-maintaining sealed sampler for shale gas and core, comprising a fishing mechanism, a spring positioning mechanism, a hanging single-acting mechanism, an in-place informing mechanism, an upper sealing mechanism, a core barrel, a core breaking mechanism and a lower sealing mechanism which are arranged in sequence together. The process from putting the pressure-maintaining sealed sampler into a shaft before drilling to taking out the core is as follows: putting in place, informing, sealing the upper end, breaking the core, sealing the lower end and fishing. The pressure-maintaining sealed sampler for shale gas and core has the advantages of low cost, a sealing function, simplicity in operation and high success rate, can expel gas originally exiting in the core barrel to reduce interference to the components of shale gas, and adopts a wire line coring mode; the core barrel has a flowing passage for drilling fluid when the sampler is put in, and the sampler can alarm after being put in place, thus speeding up the putting process.

Description

technical field [0001] The invention relates to the technical field of sealed sampling for shale gas exploration, in particular to a shale gas and core pressure-maintaining sealed sampler. Background technique [0002] Shale gas is a kind of unconventional natural gas. It occurs in organic-rich shale-based reservoir rock series. Reservoir evaluation and exploration stages are important means to evaluate the development potential of shale gas areas. The cores at the bottom of the hole are the focus of the exploration stage, and play a guiding role in the properties of oil and gas source layers and oil and gas development. The conventional coring technology will make the core come into contact with the flowing drilling fluid during the extraction process, which will change the composition and content of free gas in the core, while the sealed coring and pressure-holding sealed coring technology can keep the occurrence of the core at the bottom of the hole as much as possible. ...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the above-mentioned existing airtight coring and pressure-holding airtight coring technologies that mostly use lifting drilling to take coring, which makes the drilling efficiency very low, and easily causes accidents in the hole. During airtight coring, the cost is relatively high. High, the core is easy to corrode, which will cause pollution; the pressure-holding sealed coring mechanism is complicated, it is easy to cause sealing failure, low success rate and other problems, and a shale gas and core pressure-holding sealed sampler is provided

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