Abstract: Methods and systems are disclosed. The methods may include obtaining, from a subterranean region of interest, a rock sample having a rock type and defining a sequence of pore pressure, confining stress (PPCS) pairs such that a sequence of effective stresses monotonically changes. The methods may further include determining a sequence of permeabilities by subjecting the rock sample to the sequence of PPCS pairs and determining a relationship between the sequence of PPCS pairs and the sequence of permeabilities. The methods may further still include determining a parameter using the relationship and a permeability model, where the permeability model includes the parameter and determining an in situ permeability for an in situ rock in the subterranean region of interest using, at least in part, the parameter and the permeability model, where the in situ rock is of the rock type.

Abstract: A method for recovering a source gas at a specific pressure uses an adaptive repressurizer system including a series of valves configured to control flow circuit connections within the adaptive repressurizer system. The method includes disposing a gas container containing the source gas within the system. The method includes connecting the gas container; connecting a hydro source; connecting a utility gas source; connecting a vacuum source; and disposing an accumulator within the adaptive repressurizer system. The accumulator is connected to the gas side and to the hydraulic side circuits. The method includes moving the piston by pressurizing the gas-side circuit with the utility gas. The method includes actuating the adaptive repressurizer system to change a first gas pressure of the source gas to a second gas pressure; applying the source gas at the second gas pressure to a laboratory application; and evacuating the gas-side circuit to the vacuum source.

Abstract: A method for determining a matrix permeability of a subsurface formation, including the steps: acquiring a core from the subsurface formation, imposing a fluid to the core until the core is saturated with the fluid, conducting a pressure-pulse decay (PD) method on an upstream and a downstream side of the core by applying a pressure-pulse on the upstream and the downstream side of the core, and determining the matrix permeability from decays of the pressure-pulses on the upstream side and downstream side, respectively.

Abstract: A method for determining a matrix permeability of a subsurface formation, including the steps: acquiring a core from the subsurface formation, imposing a fluid to the core until the core is saturated with the fluid, conducting a pressure-pulse decay (PD) method on an upstream and a downstream side of the core by applying a pressure-pulse on the upstream and the downstream side of the core, and determining the matrix permeability from decays of the pressure-pulses on the upstream side and downstream side, respectively.

Abstract: A method for determining a rock property includes positioning a core sample in a core sample assembly that is enclosed in a pressurized container with a flow inlet, a flow outlet, and a pressurized fluid inlet fluidly coupled to a pressurized fluid reservoir that includes a pressurized fluid pump; sequentially performing at least three test operations on the core sample; at each of the at least three test operations, measuring an inlet pressure at the flow inlet, measuring an outlet pressure at the flow outlet, and measuring a confining pressure within the pressurized container; and determining a permeability of the core sample based at least in part on at least one of the measured inlet pressures, at least one of the measured outlet pressures, and at least one of the measured confining pressures.

Abstract: A method for determining a rock property includes positioning a core sample in a core sample assembly that is enclosed in a pressurized container with a flow inlet, a flow outlet, and a pressurized fluid inlet fluidly coupled to a pressurized fluid reservoir that includes a pressurized fluid pump; sequentially performing at least three test operations on the core sample; at each of the at least three test operations, measuring an inlet pressure at the flow inlet, measuring an outlet pressure at the flow outlet, and measuring a confining pressure within the pressurized container; and determining a permeability of the core sample based at least in part on at least one of the measured inlet pressures, at least one of the measured outlet pressures, and at least one of the measured confining pressures.

Abstract: Systems, methods, and apparatus for determining permeability of subsurface formations are provided. In one aspect, a method includes: positioning a sample of the subsurface formation in a measurement cell, fluidly connecting an inlet and an outlet of the sample to an upstream reservoir and a downstream reservoir, respectively, flowing a fluid through the sample from the upstream reservoir to the downstream reservoir, measuring changes of an upstream pressure associated with the upstream reservoir and a downstream pressure associated with the downstream reservoir in a measurement time period, and determining a matrix permeability of the subsurface formation based on measurement data before the upstream pressure and the downstream pressure merge at a merging time point.

Abstract: A method for determining stress-dependent permeability includes providing a core sample in a pressurized core container of a testing apparatus and generating a steady-state flow of gas from an upstream reservoir in the testing apparatus along an axial direction through the pressurized core container into a downstream reservoir in the testing apparatus. During the steady-state flow, an inlet pressure at an inlet to the core sample, an outlet pressure at an outlet of the core sample, and a midpoint pressure at a midpoint of the core sample are measured. The stress-dependent permeability is calculated from a flow rate of the gas through the core sample and the measurements of the inlet pressure, the outlet pressure, and the midpoint pressure.

Abstract: A method for determining stress-dependent permeability includes providing a core sample in a pressurized core container of a testing apparatus and generating a steady-state flow of gas from an upstream reservoir in the testing apparatus along an axial direction through the pressurized core container into a downstream reservoir in the testing apparatus. During the steady-state flow, an inlet pressure at an inlet to the core sample, an outlet pressure at an outlet of the core sample, and a midpoint pressure at a midpoint of the core sample are measured. The stress-dependent permeability is calculated from a flow rate of the gas through the core sample and the measurements of the inlet pressure, the outlet pressure, and the midpoint pressure.

Abstract: Systems, methods, and apparatus for determining permeability of subsurface formations are provided. In one aspect, a method includes: positioning a sample of the subsurface formation in a measurement cell, fluidly connecting an inlet and an outlet of the sample to an upstream reservoir and a downstream reservoir, respectively, flowing a fluid through the sample from the upstream reservoir to the downstream reservoir, measuring changes of an upstream pressure associated with the upstream reservoir and a downstream pressure associated with the downstream reservoir in a measurement time period, and determining a matrix permeability of the subsurface formation based on measurement data before the upstream pressure and the downstream pressure merge at a merging time point.