Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characteriz...Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characterization of granite weathering crust reservoir and provide the basis for oil exploration of granite weathering crust buried hill reservoir,in this paper,the vertical zonation of granite weathering crust reservoir is quantitatively divided by testing and analyzing the uniaxial compressive strength(UCS),magnetic susceptibility(MS),permeability,and chemical index of alteration(CIA)of the Mesozoic granite weathering crust in the coastal area of eastern Fujian.The results show that the granite weathering crust reservoir can be divided into four zones vertically:a soil zone(SZ),weathered and dissolved zone(WDZ),fracture zone(FZ),and bedrock zone(BZ).A cataclastic area is developed in the FZ and BZ,in which structural fractures are well-developed,the fracture surface density is usually greater than 200 m/m^(2),and the contribution to the fractures in the rock mass is up to about 50%,making this the sweet spot of the reservoir.In the SZ,the rocks are loose,and the pores are well-developed.The UCS is less than 10 MPa,and the average rate of change of the UCS(Δ_(σ))is 0.90.The average permeability is 2823.00 mD,and the average rate of change of the permeability(Δ_(κ))is 5.13.The average CIA is 74.9%.The average clay mineral content is 7%.The rocks in the WDZ have been significantly weathered by physical and chemical processes,and the weathering fractures and dissolution pores are well-developed.The average UCS is 18.2 MPa,and the averageΔ_(σ)is 0.70.The average permeability is 143.80 mD,and averageΔ_(κ)is 4.17.The average CIA is 65.3%.The average clay mineral content is 4%.Under the influence of tectonic movement and physical weathering,the rocks in the FZ have developed structural fractures and a few weathered fractures.The average UCS is 57.9 MPa,and the averageΔ_(σ)is 0.18.The average permeability is 5.50 mD,and the averageΔ_(κ)is 2.55.The average CIA is 61.6%.The average clay mineral content is 2%.In the BZ,the rocks are intact and hard.The average UCS is 69.9 MPa,and the average Ds is 0.13.The average permeability is 1.46 mD,and the averageΔ_(κ)is 1.43.The average CIA is 57.8%.The average clay mineral content is less than 1%.The multi-parameter combination of the UCS,Δ_(σ),permeability,Δ_(κ),CIA,and clay mineral content achieved good results in the division of the zones of the weathering crust.The UCS increases gradually from top to bottom,while Ds,permeability,Δ_(κ),CIA,and clay mineral content all decrease gradually.In addition,based on the petrophysical parameters of the rocks,including the density,resistivity,and acoustic velocity,a good division effect was also achieved,which can provide a basis for the vertical zonation of the granite buried-hill weathering crust reservoir.展开更多
Continuous variable cross-section recycled extrusion(CVCE)is an advanced technique of severe plastic deformation.Ti–6Al–4V alloy was deformed with different processing parameters by CVCE,and then the microstructure ...Continuous variable cross-section recycled extrusion(CVCE)is an advanced technique of severe plastic deformation.Ti–6Al–4V alloy was deformed with different processing parameters by CVCE,and then the microstructure characterization,refinement mechanism and deformation mechanism were investigated simultaneously.The results demonstrate that the average size of grain is refined from 14 to 2.78μm as Ti–6Al–4V alloy is deformed at 800℃ with a speed of 2 mm/s over 6 passes,and the microstructure is equiaxed and distributed homogeneously along the radial direction.Furthermore,in the process of CVCE,basal slip(0001)<110>is transformed to prismatic slip(100)<110>system and pyramidal slip(112)<113>system,with a reduction in low angle grain boundaries from 69.6%to 61.2%.Moreover,the grain refinement mechanism of CVCE is dislocation multiplication and cross-slip migration within the grain at the initial stage of deformation,which results in the formation of substructures and micro-shear bands as well as grain refinement.In addition,the nucleation and growth of dynamic recrystallization grains are beneficial to eliminating the dislocations,subgrain boundaries and other defects in the matrix,which finally results in the grains refinement.展开更多
基金supported by the Key Research and Development Program of Jilin Province(grant No.20230203107SF)the National Natural Science Foundation of China(Grant No.41790453)+1 种基金the National Key Research and Development Program of China(Grant No.2019YFC0605402)the National Major Science and Technology Project of the Ministry of Science and Technology of China(Grant No.2016ZX05026-004-001).
文摘Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characterization of granite weathering crust reservoir and provide the basis for oil exploration of granite weathering crust buried hill reservoir,in this paper,the vertical zonation of granite weathering crust reservoir is quantitatively divided by testing and analyzing the uniaxial compressive strength(UCS),magnetic susceptibility(MS),permeability,and chemical index of alteration(CIA)of the Mesozoic granite weathering crust in the coastal area of eastern Fujian.The results show that the granite weathering crust reservoir can be divided into four zones vertically:a soil zone(SZ),weathered and dissolved zone(WDZ),fracture zone(FZ),and bedrock zone(BZ).A cataclastic area is developed in the FZ and BZ,in which structural fractures are well-developed,the fracture surface density is usually greater than 200 m/m^(2),and the contribution to the fractures in the rock mass is up to about 50%,making this the sweet spot of the reservoir.In the SZ,the rocks are loose,and the pores are well-developed.The UCS is less than 10 MPa,and the average rate of change of the UCS(Δ_(σ))is 0.90.The average permeability is 2823.00 mD,and the average rate of change of the permeability(Δ_(κ))is 5.13.The average CIA is 74.9%.The average clay mineral content is 7%.The rocks in the WDZ have been significantly weathered by physical and chemical processes,and the weathering fractures and dissolution pores are well-developed.The average UCS is 18.2 MPa,and the averageΔ_(σ)is 0.70.The average permeability is 143.80 mD,and averageΔ_(κ)is 4.17.The average CIA is 65.3%.The average clay mineral content is 4%.Under the influence of tectonic movement and physical weathering,the rocks in the FZ have developed structural fractures and a few weathered fractures.The average UCS is 57.9 MPa,and the averageΔ_(σ)is 0.18.The average permeability is 5.50 mD,and the averageΔ_(κ)is 2.55.The average CIA is 61.6%.The average clay mineral content is 2%.In the BZ,the rocks are intact and hard.The average UCS is 69.9 MPa,and the average Ds is 0.13.The average permeability is 1.46 mD,and the averageΔ_(κ)is 1.43.The average CIA is 57.8%.The average clay mineral content is less than 1%.The multi-parameter combination of the UCS,Δ_(σ),permeability,Δ_(κ),CIA,and clay mineral content achieved good results in the division of the zones of the weathering crust.The UCS increases gradually from top to bottom,while Ds,permeability,Δ_(κ),CIA,and clay mineral content all decrease gradually.In addition,based on the petrophysical parameters of the rocks,including the density,resistivity,and acoustic velocity,a good division effect was also achieved,which can provide a basis for the vertical zonation of the granite buried-hill weathering crust reservoir.
基金supported by the fund of National Natural Science Foundation of China(No.U25A20205)Xi'an Science and Technology Plan Program(No.24LLRHZDZX0008)+1 种基金Key R&D Project in Shaanxi Province(No.2024GX-YBXM-211)Xianyang Science and Technology Plan Program(No.L2025-ZDYF-GDZB-014).
文摘Continuous variable cross-section recycled extrusion(CVCE)is an advanced technique of severe plastic deformation.Ti–6Al–4V alloy was deformed with different processing parameters by CVCE,and then the microstructure characterization,refinement mechanism and deformation mechanism were investigated simultaneously.The results demonstrate that the average size of grain is refined from 14 to 2.78μm as Ti–6Al–4V alloy is deformed at 800℃ with a speed of 2 mm/s over 6 passes,and the microstructure is equiaxed and distributed homogeneously along the radial direction.Furthermore,in the process of CVCE,basal slip(0001)<110>is transformed to prismatic slip(100)<110>system and pyramidal slip(112)<113>system,with a reduction in low angle grain boundaries from 69.6%to 61.2%.Moreover,the grain refinement mechanism of CVCE is dislocation multiplication and cross-slip migration within the grain at the initial stage of deformation,which results in the formation of substructures and micro-shear bands as well as grain refinement.In addition,the nucleation and growth of dynamic recrystallization grains are beneficial to eliminating the dislocations,subgrain boundaries and other defects in the matrix,which finally results in the grains refinement.
