Research on variogram analysis method for 3D modeling of sandstone reservoir

Analysis of variogram is a necessary step in 3D stochastic modeling, and different settings of variograms can directly affect the final distribution of model attribute. How to optimize the setting of variogram parameters by unit and facies type has become a key step in geological modeling. This article focuses on the reservoir within sedimentary background of fluvial-deltas in the layer SII7+8 which develops multiple sedimentary microfacies, such as fluvial channels, abandoned fluvial channels, flood plains, and natural levee with strong heterogeneity, so as to study the impact of changes of the variogram parameters on the simulation results of reservoir properties, in order to explore the analysis method of the variogram. On this basis, the reservoir is divided into 3 types of sand bodies and 11 types of sedimentary microfacies based on net pay thickness, sedimentary environment, and main sand scale and morphology. The distribution characteristics and extension scale of different facies types on the plane are classified and studied, in order to determine the characteristic parameters of the variogram of different types of sand bodies, accurately simulate the distribution characteristics of reservoir physical property, and further improve the accuracy of the 3D attribute model

Research on variogram analysis method for 3D modeling of sandstone reservoir

Analysis of variogram is a necessary step in 3D stochastic modeling, and different settings of variograms can directly affect the final distribution of model attribute. How to optimize the setting of variogram parameters by unit and facies type has become a key step in geological modeling. This article focuses on the reservoir within sedimentary background of fluvial-deltas in the layer SII7+8 which develops multiple sedimentary microfacies, such as fluvial channels, abandoned fluvial channels, flood plains, and natural levee with strong heterogeneity, so as to study the impact of changes of the variogram parameters on the simulation results of reservoir properties, in order to explore the analysis method of the variogram. On this basis, the reservoir is divided into 3 types of sand bodies and 11 types of sedimentary microfacies based on net pay thickness, sedimentary environment, and main sand scale and morphology. The distribution characteristics and extension scale of different facies types on the plane are classified and studied, in order to determine the characteristic parameters of the variogram of different types of sand bodies, accurately simulate the distribution characteristics of reservoir physical property, and further improve the accuracy of the 3D attribute model

A New Phenomenological Model for Single Particle Erosion of Plastic Materials

A phenomenological model for single particle erosion (SPE) of plastic materials was constructed based on the Hertzian contact theory and conservation of momentum to solve the particle impact erosion. The extrusion deformation and contact time of materials in three processes of wall elastic extrusion, elastic-plastic extrusion, and elastic recovery were discussed. Later, the critical angle for sliding contact between the particle and metal surface was calculated according to the impact angle of a particle and the corresponding critical sliding friction force of the particle. The wall indentation depths under sliding contact and no sliding contact were compared. Finally, the erosion volume of materials by impact of a single particle was gained. Moreover, a contrastive analysis on calculation results was carried out by using the gas-solid jet erosion experiment. Contact time, normal and tangential deformations of materials, as well as material erosion under sliding contact and no sliding contact in two processes of particle extrusion and rebound were gained from calculation and experiment. The constructed model showed a good agreement without involving too many empirical coefficients

Cholesterol Stabilizes TAZ in Hepatocytes to Promote Experimental Non-alcoholic Steatohepatitis.

Incomplete understanding of how hepatosteatosis transitions to fibrotic non-alcoholic steatohepatitis (NASH) has limited therapeutic options. Two molecules that are elevated in hepatocytes in human NASH liver are cholesterol, whose mechanistic link to NASH remains incompletely understood, and TAZ, a transcriptional regulator that promotes fibrosis but whose mechanism of increase in NASH is unknown. We now show that increased hepatocyte cholesterol upregulates TAZ and promotes fibrotic NASH. ASTER-B/C-mediated internalization of plasma membrane cholesterol activates soluble adenylyl cyclase (sAC; ADCY10), triggering a calcium-RhoA-mediated pathway that suppresses β-TrCP/proteasome-mediated TAZ degradation. In mice fed with a cholesterol-rich NASH-inducing diet, hepatocyte-specific silencing of ASTER-B/C, sAC, or RhoA decreased TAZ and ameliorated fibrotic NASH. The cholesterol-TAZ pathway is present in primary human hepatocytes, and associations among liver cholesterol, TAZ, and RhoA in human NASH liver are consistent with the pathway. Thus, hepatocyte cholesterol contributes to fibrotic NASH by increasing TAZ, suggesting new targets for therapeutic intervention