Design and verification of pressure-preserved computed tomography testing for deep oil and gas exploration

: Pressure-preserved coring is a highly effective technique for preserving the structural integrity and fluid composition of reservoir cores. However, the lack of specialized testing methodologies hinders the precise evaluation of pressure-preserved core fidelity parameters. To address this challenge, a comprehensive study was conducted on the entire process of pressure-preserved transfer, cutting, and testing, culminating in the development of a pressure-preserved computed tomography (CT) scanning device. The critical technical challenges encountered during the development process were systematically analyzed through mechanical testing, CT scanning, and numerical simulations. Special emphasis was placed on material influences during testing, mechanical assembly interactions, and the accuracy of key parameter measurements in oil and gas exploration. Through comparative analysis and multitiered validation methods, polyether ether ketone (PEEK) material was ultimately selected as the key component of the coring device. The simulation and experimental results demonstrated that PEEK, with a maximum tensile strength of 104 MPa, sufficiently meets most core breakage thresholds of 93.942 MPa. Furthermore, CT scanning revealed a porosity measurement error of only 0.111%, confirming the reliability of the pressure-preserved CT test equipment. These findings offer valuable guidance for improving the precision of pressure-preserved core testing in deep oil and gas reservoirs.