Method and device for measuring rock gas content data

Abstract

The embodiment of the invention discloses a method and device for testing gas containing data of rock. The method comprises the steps of placing the rock to be tested into a desorption device for natural desorption, and monitoring desorption rate; obtaining the function relationship between the desorption rate and desorption time through fitting, and calculating the volume of lost gas according to the function relationship; conducting natural desorption till it is monitored that gas in the rock to be tested is completely desorbed, and measuring the volume of desorbed gas obtained from natural desorption and fast desorption; adding the volume of the lost gas and the volume of the desorbed gas together to obtain total volume, and then obtaining the gas content of the rock to be tested through calculation. By the adoption of the embodiments of the invention, testing processes can be effectively simplified, and the accuracy of a test result is improved.

Description

technical field [0001] The present application relates to the technical field of oil and gas exploration and development, in particular to a method and device for measuring gas-bearing data in rocks. Background technique [0002] With the rapid development of my country's economy, the supply of oil and gas resources is becoming more and more tense. The exploration and development of unconventional oil and gas resources such as shale gas, coalbed methane and shale oil have been paid attention to. Rock gas content is a key parameter to evaluate the quality of resources such as shale gas and coalbed methane, and how to accurately measure rock gas content is particularly important. [0003] In the prior art, the most widely used method for determining the gas content of rocks is the US Bureau of Mines direct method, which divides the gas contained in the rock to be tested into three parts: desorbed gas, lost gas and residual gas, three parts The quantitative relationship of th...

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Problems solved by technology

In this method, the definition of the desorption gas is that after the rock to be tested is packed into the desorption device and sealed, the gas desorbed from the rock to be tested under certain temperature, pressure and time conditions, its volume can be directly measured, But this process needs to be carried out more than one week, and efficiency is low; The definition of described loss gas is, the gas that the rock to be measured is desorbed during the time that the rock to be tested encounters the rock to be tested to the time that the rock to be tested is packed into the desorption device, and this part of gas The volume of the desorbed gas cannot be directly measured, and it needs to be calculated by the law of the desorbed gas volume changing with time. However, since the pressure in the atmospheric environment is different from the pressure in the formation, the desorption law is different. According to the law, the total volume of gas lost in the atmosphere and in the formation will be calculated, which will cause a large error; the definition of the residual gas is that a part of the rock to be tested is taken out and crushed after the rock to be tested is naturally desorbed in the desorption device, The volume of gas remaining in the desorbed rock to be tested can be directly measured, but during the period from opening the desorption device to crushing the rock to be tested, some gas escapes, the volume of this part of gas Difficult to measure, leading to errors in the final measurement results

[0015] There are at least the following problems in the prior art: the measurement process takes a long time, the process is cumbersome, and the gas escaped during the measurement process is difficult to measure, resulting in errors in the measurement results

In addition, the accuracy of the calculation method of the lost gas in the prior art is low, and the calculation result of the lost gas deviates greatly from the real value

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