Study of a low-disturbance pressure-preserving corer and its coring performance in deep coal mining conditions

Abstract

With the increasing depth of coal mining, the requirements for coring devices that maintain pressure are increasing. To adapt to the special environment in deep coal seams and improve the accuracy of testing gas content, a low-disturbance pressure-preserving corer was developed. The measurement of gas content using this corer was analyzed. The coring test platform was used to complete a coring function test. A pressurized core with a diameter of 50 mm was obtained. The pressure was 0.15 MPa, which was equal to the pressure of the liquid column of the cored layer, indicating that the corer can be successfully used in a mud environment. Next, a pressure test of the corer was conducted. The results showed that under conditions of low pressure (8 MPa) and high pressure (25 MPa), the internal pressure of the corer remained stable for more than 1 h, indicating that the corer has good ability to maintain pressure. Therefore, the corer can be applied at deep coal mine sites. The results of this research can be used to promote the safe exploitation of deep coal mines and the exploitation of methane resources in coalbeds.