tailieunhanh - Phân tích trạng thái ứng suất xung quanh giếng khoan trong môi trường đá nóng - đàn hồi - bão hòa

Bài viết tích trạng thái ứng suất xung quanh giếng khoan trong môi trường đá nóng - đàn hồi - bão hòa trình bày về trạng thái ứng suất xung quanh giếng khoan đặt trong môi trường đá nóng, đàn hồi đồng nhất, đẳng hướng và ở trạng thái bão hòa. | Journal of Mining and Earth Sciences Vol. 64 Issue 2 2023 101 - 114 101 Analysis of the stress state around wellbores in saturated porothermoelastic rock Hung Nam Tran 1 Truong Hung Trieu 2 Nga Thu Thi Nguyen 1 1 Le Quy Don Technical University Hanoi Vietnam 2 Hanoi University of Mining and Geology Hanoi Vietnam ARTICLE INFO ABSTRACT Article history In the oil and gas exploitation or geo-thermal energy exploitation Received 26th Dec. 2022 industries wellbores can be drilled at great depths where the formation Revised 02nd Mar. 2023 would be hot and saturated. In such case a large temperature difference Accepted 17th Mar. 2023 between the rock mass and drilling fluid can occur and cannot be ignored. Keywords During drilling the wellbores thermic hydraulic and mechanical Cooling phenomena appear simultaneously and interact with each other within Fully thermo-hydro-mechanical the rock. This study presents the analysis of stress state around the wellbore located in saturated hot rock based on the fully thermo-hydro- model mechanical behavior model of the rock mass by the finite element method. Heating Two scenarios involving thermal conditions at the well wall are taken into Stress state account . the drilling fluid temperature is lower or higher than the Wellbore. formation temperature so-called the cases of cooling and heating respectively. In this study the influence of some thermic hydraulic and initial stress field parameters of the rock mass on the stress state around the wellbore was also clarified. The obtained results showed that in the cooling case the well wall may be destabilized by fracture failure while in the heating case this would be collapse failure. The maximum points of tangential and axial stresses appear at the same locations for the two scenarios. In addition the thermal expansion coefficient the initial shear stress in the rock mass greatly affect the stress state around the wellbore whilst the permeability of the formation does not .