Research on in-situ condition preserved coring and testing systems
Heping Xie, Tao Liu, Mingzhong Gao, Ling Chen, Hong Zhou, Yang Ju, Feng Gao, Xiaobo Peng, Xiongjun Li, Ruidong Peng, Yanan Gao, Cong Li, Zhiqiang He, Mingqing Yang, Zhiyu Zhao
Abstract
As shallow resources are increasingly depleted, the mechanics’ theory and testing technology of deep in-situ rock has become urgent. Traditional coring technologies obtain rock samples without retaining the in-situ environmental conditions, leading to distortion of the measured parameters. Herein, a coring and testing systems retaining in-situ geological conditions is presented: the coring system that obtains in-situ rock samples, and the transfer and testing system that stores and analyzes the rocks under a reconstructed environment. The ICP-Coring system mainly consists of the pressure controller, active insulated core reactor and insulation layer and sealing film. The ultimate bearing strength of 100 MPa for pressure-preservation, temperature control accuracy of 0.97% for temperature-retained are realized. CH4 and CO permeability of the optimized sealing film are as low as 3.85 and 0.33 ppm/min. The average tensile elongation of the film is 152.4% and the light transmittance is reduced to 0%. Additionally, the pressure and steady-state temperature accuracy for reconstructing the in-situ environment of transfer and storage system up to 1% and ±0.2 is achieved. The error recorded of the noncontact sensor ring made of low-density polymer is less than 6% than that of the contact test. The system can provide technical support for the deep in-situ rock mechanics research, improving deep resource acquisition capabilities and further clarifying deep-earth processes.