Experimental apparatus for evaluating coalbed methane cave well completion

Abstract

The invention provides an experimental apparatus for evaluating coalbed methane cave well completion. The device comprises a cube coal petrography model arranged in a frame, wherein the bottom surface of the coal petrography model is provided with a wellbore hole simulator extending upwards, the top surface of the coal petrography model is provided with a plurality of pressure taps extending downwards, a seal rubber cover is arranged outside the coal petrography model, press plates are fixed on the six side faces which are at the outer side of the rubber cover and correspond to the coal petrography model, through holes are respectively arranged at on the press plates at the upper side and the lower side and at the parts of the rubber cover, which correspond to the wellbore hole simulator and the pressure taps, and each pressure tap is internally provided with a pressure test pipe with a pressure sensor; three server pressuring oil cylinders are arranged in three directions in an outer space of the coal petrography model; and a communicating vessel is arranged on the press plate at the lower side in a sealing way and is communicated with the wellbore hole simulator, the upper part of the communicating vessel is provided with a gas inlet pipe, a water inlet pipe and a pressure test pipe with the pressure sensor, the lower part of the communicating vessel is provided with an electric ball vale, the lower end of the electric ball vale is connected with a pressure release pipe, and the bottom end of the pressure release pipe is correspondingly provided with a pulverized coal collecting water tank.

Description

technical field [0001] The invention relates to a well completion simulation experiment system, in particular to a coalbed methane cave completion evaluation experiment device. Background technique [0002] In 1986, Meridian Petroleum Company began to use the open-hole cave completion technology in the San Juan Basin of the United States to collapse the target coal seam to expand the wellbore to form caves. 3-20 times, and the cost is lower than that of large-scale hydraulic fracturing. So far, there have been more than 4,000 coalbed methane wells in the San Juan Basin, 1 / 3 of which are cave completions, and the cumulative gas production of cave completions accounts for the entire basin's gas production 76% of. [0003] Compared with the coalbed methane cavern completion in the United States, due to equipment and cognition reasons, my country's coalbed methane cavern completion has not really realized bottomhole pressure excitation or stress fluctuation inside the coal seam...

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Problems solved by technology

[0005] However, due to the huge investment, time-consuming, high risk and cost of field tests for coalbed methane cave completion, it does not have the ability to conduct rapid, multiple, and multi-layer experiments, and it is very difficult to measure and collect relevant experimental data, and even if the cave completion However, its stimulation mechanism is difficult to explain and analyze. Therefore, there are very few studies on the stimulation mechanism and process flow of coalbed methane cavern completion in my country.

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