When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two...When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two layers of soil with different properties, pore water flows slowly along the pore channels, demonstrating laminar flow phenomenon. To predict the thermal contact resistance and flow contact resistance at the interface, this paper constructs general imperfect thermal contact model and general imperfect flow contact model, respectively. Utilizing a thermo-hydro- mechanical coupling model, the thermal consolidation behavior of multilayered saturated soil under two-dimensional conditions is investigated. Fourier and Laplace transformations are applied to decouple the governing equations, yielding expressions for the temperature increment, pore water pressure, and displacement in multilayered saturated soil. The inverse Fourier-Laplace transformation is then used to obtain numerical solutions, which are compared with degeneration solutions to validate the computational accuracy. The differences in the thermal consolidation process under various thermal contact and flow contact resistance models are discussed. Furthermore, the impact of parameters such as the thermal resistance coefficient, partition thermal contact coefficient, flow contact resistance coefficient, and partition flow contact coefficient on thermal consolidation are investigated. Results indicate that thermal contact resistance creates a relative thermal gradient at the interface, leading to increased pore water pressure and reduced displacement nearby. In contrast, flow contact resistance generates a relative pore pressure gradient at the interface, resulting in increased displacement within the saturated soil with minimal effect on temperature increment distribution.展开更多
Ramp-type bioherm is geologically characterized by lateral migration,small size and discrete distribution.The fine bioherm description is of high difficulty and the benefit development of bioherm gas reservoirs can be...Ramp-type bioherm is geologically characterized by lateral migration,small size and discrete distribution.The fine bioherm description is of high difficulty and the benefit development of bioherm gas reservoirs can be hardly realized.To solve these difficulties,this paper put forward a new bioherm identification method based on well-seismic combination after cognizing the geological characteristics of ramp-type bioherms deeply.And this new method plays a successful role in guiding the drilling ofWell Y012-X16 in the mode of“two bioherms in one well”in the Damaoping Block of eastern Sichuan Basin.High-yield industrial gas flow of 113.65×10^(4)m^(3)/d is obtained during the test and great new progress is achieved in the exploration of bioherm gas reservoirs.And the following research results were obtained.First,the degree of slope at the marginal platform slope of ramp-type bioherm is only 2°-4°.The migration and evolution laws of bioherms are mainly controlled by the change of paleogeomorphology and sea level.As a result,small bioherms of multiple rows and multiple periods are formed and the gas-water contact of ramp-type bioherm gas reservoir is not united,presenting the characteristics of“one bioherm,one reservoir”.The gas bearing property is good at the top of the bioherm.The overall gas bearing property is poorer in the early bioherm of the second member of Upper Permian Changxing Formation and better in the late bioherm of the third member of Changxing Formation.Second,a new bioherm identification method with“double-high”integrated seismic processing technology,data driven“box-shaped volume”perspective technology,remaining thickness method based sedimentary paleogeomorphology restoration technology and three-dimensional visualization technology as the core is developed innovatively,which provides the fine description of ramp-type small bioherms in the three dimensional space.Third,based on the application of the new bioherm identification method,the distribution detail of the bioherms in the Damaoping Block is clarified,the development mode of“two bioherms in onewell”for long horizontal sections is established and a PetroChina's new record of bioherm reservoir drilling length is set up in Well Y012-X16,which launches a new means to the benefit development of small bioherm group.Fourth,it is predicted that a number of bioherm development areas can be newly increased in the Damaoping Block,which can provide the supplement productivity of 100×10^(4)m^(3)/d for the development of gas reservoirs,so their natural gas exploration and development potential is huge.In conclusion,the fine description technologies for ramp-type small bioherms are conducive to the identification of ramp-type small bioherm group and the efficient exploration and development of bioherm gas reservoirs in the Sichuan Basin.展开更多
In extreme heat transfer environments, functionally graded materials(FGMs)have aroused great concern due to the excellent thermal shock resistance. With the development of micro-scale devices, the size-dependent effec...In extreme heat transfer environments, functionally graded materials(FGMs)have aroused great concern due to the excellent thermal shock resistance. With the development of micro-scale devices, the size-dependent effect has become an important issue. However, the classical continuum mechanical model fails on the micro-scale due to the influence of the size-dependent effect. Meanwhile, for thermoelastic behaviors limited to small-scale problems, Fourier's heat conduction law cannot explain the thermal wave effect. In order to capture the size-dependent effect and the thermal wave effect, the nonlocal generalized thermoelastic theory for the formulation of an FGM microbeam is adopted in the present work. For numerical validation, the transient responses for a simply supported FGM microbeam heated by the ramp-type heating are considered.The governing equations are formulated and solved by employing the Laplace transform techniques. In the numerical results, the effects of the ramp-heating time parameter, the nonlocal parameter, and the power-law index on the considered physical quantities are presented and discussed in detail.展开更多
基金Projects(52108347, 52179112, 52178371) supported by the National Natural Science Foundation of ChinaProjects(2020C01147, 2023C01165) supported by the Primary Research and Development Plan of Zhejiang Province,ChinaProject(LQ22E080010) supported by the Outstanding Youth Project of Natural Science Foundation of Zhejiang Province,China。
文摘When the interface of a multilayered saturated soil is rough with noticeable gaps, heat flow lines converge towards the actual contact points, causing thermal flow contraction. Conversely, in the interface between two layers of soil with different properties, pore water flows slowly along the pore channels, demonstrating laminar flow phenomenon. To predict the thermal contact resistance and flow contact resistance at the interface, this paper constructs general imperfect thermal contact model and general imperfect flow contact model, respectively. Utilizing a thermo-hydro- mechanical coupling model, the thermal consolidation behavior of multilayered saturated soil under two-dimensional conditions is investigated. Fourier and Laplace transformations are applied to decouple the governing equations, yielding expressions for the temperature increment, pore water pressure, and displacement in multilayered saturated soil. The inverse Fourier-Laplace transformation is then used to obtain numerical solutions, which are compared with degeneration solutions to validate the computational accuracy. The differences in the thermal consolidation process under various thermal contact and flow contact resistance models are discussed. Furthermore, the impact of parameters such as the thermal resistance coefficient, partition thermal contact coefficient, flow contact resistance coefficient, and partition flow contact coefficient on thermal consolidation are investigated. Results indicate that thermal contact resistance creates a relative thermal gradient at the interface, leading to increased pore water pressure and reduced displacement nearby. In contrast, flow contact resistance generates a relative pore pressure gradient at the interface, resulting in increased displacement within the saturated soil with minimal effect on temperature increment distribution.
基金Project supported by the National Major Science and Technology Project“Demonstrative project of large carbonate gas field development in Sichuan Basin”(No.2016ZX05052)PetroChina Major Science and Technology Project“Research and application of key technology for a productivity of 30 billion cubic meters in Southwest Oil and Gas Field”(No.2016E-06).
文摘Ramp-type bioherm is geologically characterized by lateral migration,small size and discrete distribution.The fine bioherm description is of high difficulty and the benefit development of bioherm gas reservoirs can be hardly realized.To solve these difficulties,this paper put forward a new bioherm identification method based on well-seismic combination after cognizing the geological characteristics of ramp-type bioherms deeply.And this new method plays a successful role in guiding the drilling ofWell Y012-X16 in the mode of“two bioherms in one well”in the Damaoping Block of eastern Sichuan Basin.High-yield industrial gas flow of 113.65×10^(4)m^(3)/d is obtained during the test and great new progress is achieved in the exploration of bioherm gas reservoirs.And the following research results were obtained.First,the degree of slope at the marginal platform slope of ramp-type bioherm is only 2°-4°.The migration and evolution laws of bioherms are mainly controlled by the change of paleogeomorphology and sea level.As a result,small bioherms of multiple rows and multiple periods are formed and the gas-water contact of ramp-type bioherm gas reservoir is not united,presenting the characteristics of“one bioherm,one reservoir”.The gas bearing property is good at the top of the bioherm.The overall gas bearing property is poorer in the early bioherm of the second member of Upper Permian Changxing Formation and better in the late bioherm of the third member of Changxing Formation.Second,a new bioherm identification method with“double-high”integrated seismic processing technology,data driven“box-shaped volume”perspective technology,remaining thickness method based sedimentary paleogeomorphology restoration technology and three-dimensional visualization technology as the core is developed innovatively,which provides the fine description of ramp-type small bioherms in the three dimensional space.Third,based on the application of the new bioherm identification method,the distribution detail of the bioherms in the Damaoping Block is clarified,the development mode of“two bioherms in onewell”for long horizontal sections is established and a PetroChina's new record of bioherm reservoir drilling length is set up in Well Y012-X16,which launches a new means to the benefit development of small bioherm group.Fourth,it is predicted that a number of bioherm development areas can be newly increased in the Damaoping Block,which can provide the supplement productivity of 100×10^(4)m^(3)/d for the development of gas reservoirs,so their natural gas exploration and development potential is huge.In conclusion,the fine description technologies for ramp-type small bioherms are conducive to the identification of ramp-type small bioherm group and the efficient exploration and development of bioherm gas reservoirs in the Sichuan Basin.
基金Project supported by the National Natural Science Foundation of China (Nos. 11972176 and12062011)the Incubation Programme of Excellent Doctoral Dissertation-Lanzhou University of Technology。
文摘In extreme heat transfer environments, functionally graded materials(FGMs)have aroused great concern due to the excellent thermal shock resistance. With the development of micro-scale devices, the size-dependent effect has become an important issue. However, the classical continuum mechanical model fails on the micro-scale due to the influence of the size-dependent effect. Meanwhile, for thermoelastic behaviors limited to small-scale problems, Fourier's heat conduction law cannot explain the thermal wave effect. In order to capture the size-dependent effect and the thermal wave effect, the nonlocal generalized thermoelastic theory for the formulation of an FGM microbeam is adopted in the present work. For numerical validation, the transient responses for a simply supported FGM microbeam heated by the ramp-type heating are considered.The governing equations are formulated and solved by employing the Laplace transform techniques. In the numerical results, the effects of the ramp-heating time parameter, the nonlocal parameter, and the power-law index on the considered physical quantities are presented and discussed in detail.
