Research on in-situ condition preserved coring and testing systems

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.