Abstract: A power supply system includes a power conditioning apparatus, a transformer, and a controller. The power conditioning apparatus includes an inverter circuit, at least one grid-connected switch, a voltage-to-ground detector. The inverter circuit is configured to connect to the inverter circuit is configured to connect to the transformer through the at least one grid-connected switch, and the transformer is configured to connect to a power grid. When one grid-connected switch is turned off and turned on, the voltage-to-ground detector detects voltage to grounds of the power conditioning apparatus to obtain a first voltage value and a second voltage value respectively. The controller outputs alarm information for grounding of a neutral wire of the transformer or controls the power conditioning apparatus to stop working when a difference between the second voltage value and the first voltage value falls within a preset voltage range.

Abstract: Disclosed are computer implemented techniques for conducting a simulation of physical properties of a porous medium. The features include receiving a micro-CT 3D image that captures a representative elemental volume of the porous medium, the porous medium defined as having mineral types and fluid types with individual grains and grain to grain contacts, labeling the micro-CT 3D image as individual voxels according to mineral and fluid types and labeling the mineral type voxels as belonging to separated and fixed individual grains. The features also include transforming the labeled voxels into an unstructured conformal mesh representation for all grains and applying the unstructured conformal mesh representation to a parametric cohesive contact engine, with the parametric cohesive contact engine executing a parametric cohesive contact model that has an adjustable parameter, a critical separation ?0 conditioned according to consolidation level.

Abstract: Disclosed are computer implemented techniques for conducting a simulation of physical properties of a porous medium. The features include receiving a micro-CT 3D image that captures a representative elemental volume of the porous medium, the porous medium defined as having mineral types and fluid types with individual grains and grain to grain contacts, labeling the micro-CT 3D image as individual voxels according to mineral and fluid types and labeling the mineral type voxels as belonging to separated and fixed individual grains. The features also include transforming the labeled voxels into an unstructured conformal mesh representation for all grains and applying the unstructured conformal mesh representation to a parametric cohesive contact engine, with the parametric cohesive contact engine executing a parametric cohesive contact model that has an adjustable parameter, a critical separation ?0 conditioned according to consolidation level.

Abstract: Methods and systems for increasing normalized production rate of an oil and gas reservoir by optimizing a pressure drawdown of a subsurface formation are disclosed. The methods include determining permeability of the subsurface formation as a function of effective stresses, determining a stress sensitivity factor for the core sample, upscaling the sensitive stress factor, determining the optimum pressure drawdown for the subsurface formation, and controlling the pressure drawdown in a field operation such that it does not exceed the optimum pressure drawdown for the subsurface formation.

Abstract: Disclosed are computer implemented techniques for conducting a simulation of physical properties of a porous medium. The features include receiving a micro-CT 3D image that captures a representative elemental volume of the porous medium, the porous medium defined as having mineral types and fluid types with individual grains and grain to grain contacts, labeling the micro-CT 3D image as individual voxels according to mineral and fluid types and labeling the mineral type voxels as belonging to separated and fixed individual grains. The features also include transforming the labeled voxels into an unstructured conformal mesh representation for all grains and applying the unstructured conformal mesh representation to a parametric cohesive contact engine, with the parametric cohesive contact engine executing a parametric cohesive contact model that has an adjustable parameter, a critical separation ?0 conditioned according to consolidation level.

Abstract: Methods and systems for increasing normalized production rate of an oil and gas reservoir by optimizing the pressure drawdown of the subsurface formation are disclosed. The method includes determining permeability of the subsurface formation as a function of effective stresses, determining stress sensitivity factor, upscaling the permeability values determined for the core sample, determining the optimum pressure drawdown for the subsurface formation, controlling the pressure drawdown in a field operation such that it does not exceed the optimum pressure drawdown for the subsurface formation.