Design and strength analysis of the passive thermal insulation structure of a deep rock in-situ thermal insulation coring system

Abstract

The zero-sum game between the strength of deep in-situ thermal insulation coring structures and the performance of passive thermal insulation materials seriously restricts the exploration and development of deep resources. In this paper, an innovative thermal insulation coring structure based on passive thermal insulation material is designed, and a strength analysis of thermal insulation material is carried out based on the elastic theory of multilayer cylinders, which reveals the stress distribution and deformation law of thermal insulation material in a deep in-situ environment. The reliability of the results is verified by comparisons between the numerical simulation and theoretical derivation. The results show that for deep coring environments of 150?C and 140 MPa, the wall thickness and diameter of the corer can be greatly reduced by directly coating the insulation material on the surface of the core barrel. This paper can provide a reference for the design and engineering application of deep rock in situ thermal insulation coring systems.