Methods and systems for determining fracture and matrix permeability of a subsurface formation. The system includes two upstream reservoirs and two downstream reservoirs, and a sample cell connecting to the reservoirs with valves. The sample cell has a confining pressure (CF) from a fluid. A horizontal plug sample with sleeve is placed in a measurement cell with the confining fluid (CF). A pressure gauge is connected to the small upstream reservoir, and a pressure gauge is connected to the small downstream reservoir. The results provide two sets of effective-stress-dependent permeability values (including fracture permeability and matrix permeability, respectively) for characterizing the reservoir properties.

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.

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.

A device for measuring a chemical potential of a fluid in a plant tissue includes a cavity disposed within a sensor body as a liquid reservoir. The cavity is configured for containing therein a liquid, and the cavity including at least one opening. At least two porous membrane layers are positioned at least in part over the at least one opening of the cavity for selectively allowing water transfer between the plant fluid and the liquid in the cavity. At least one pressure sensor is configured for detecting changes in pressure of the liquid in the cavity. The changes are related to a chemical potential of the fluid in the plant tissue.

A device for measuring a chemical potential of a fluid in a plant tissue includes a cavity disposed within a sensor body as a liquid reservoir. The cavity is configured for containing therein a liquid, and the cavity including at least one opening. At least two porous membrane layers are positioned at least in part over the at least one opening of the cavity for selectively allowing water transfer between the plant fluid and the liquid in the cavity. At least one pressure sensor is configured for detecting changes in pressure of the liquid in the cavity. The changes are related to a chemical potential of the fluid in the plant tissue.

Determination of transport phenomena properties in porous media is one major objective of core analysis studies in petrophysics, reservoir engineering, and groundwater hydrology. Porosity measurement may be considered as a key factor to identify the hydraulic performance of a low permeable porous medium (e.g. rock or concrete). Additionally, the rate of absorption under pressure depends on the permeability, which is related to the connectivity between the existing pores within the porous structure. An alternative Gas Expansion Induced Water Intrusion Porosimetry (GEIWIP) method and apparatus is useful to measure the total porosity and pore size distribution, using a gas/water intrusion apparatus for water tight materials.

Determination of transport phenomena properties in porous media is one major objective of core analysis studies in petrophysics, reservoir engineering, and groundwater hydrology. Porosity measurement may be considered as a key factor to identify the hydraulic performance of a low permeable porous medium (e.g. rock or concrete). Additionally, the rate of absorption under pressure depends on the permeability, which is related to the connectivity between the existing pores within the porous structure. An alternative Gas Expansion Induced Water Intrusion Porosimetry (GEIWIP) method and apparatus is useful to measure the total porosity and pore size distribution, using a gas/water intrusion apparatus for water tight materials.

The present disclosure relates to a system and a method for gas fingerprinting. The system includes multiple holders having a distinct gas-permeable membrane disposed of therewithin such that a confined space is created behind the membranes. The test gas is pressurized in a single gas reservoir and is allowed to permeate through the membranes into respective confined spaces. The accumulated pressure values behind the utilized membranes (in the confined spaces) at a given time, are simultaneously recorded using pressure sensors. The recorded gas accumulation data is processed by a computing device to determine a characteristic property for each test gas. The system ability to fingerprint gases is demonstrated by ten test gases including helium, neon, argon, hydrogen, nitrogen, carbon dioxide, methane, ethane, propane, and ethylene, and is also able to discriminate between closely related gases.

The present disclosure relates to a system and a method for gas fingerprinting. The system includes multiple holders having a distinct gas-permeable membrane disposed of therewithin such that a confined space is created behind the membranes. The test gas is pressurized in a single gas reservoir and is allowed to permeate through the membranes into respective confined spaces. The accumulated pressure values behind the utilized membranes (in the confined spaces) at a given time, are simultaneously recorded using pressure sensors. The recorded gas accumulation data is processed by a computing device to determine a characteristic property for each test gas. The system ability to fingerprint gases is demonstrated by ten test gases including helium, neon, argon, hydrogen, nitrogen, carbon dioxide, methane, ethane, propane, and ethylene, and is also able to discriminate between closely related gases.

Methods and systems for selecting a set of fast computable functions to assess core properties of entities are disclosed. A method includes: receiving a request to select a set of fast computable functions to determine core properties of an entity; determining, for each of a plurality of fast computable function nodes in a directed graph, a set of core property nodes in the directed graph that are connected to the fast computable function node; adding, to a solution set, a fast computable function node that is connected to a highest number of core property nodes that are currently unconnected to nodes in the solution set; repeating the adding until each of the core property nodes is connected to at least one of the nodes in the solution set; and outputting the fast computable function nodes in the solution set in response to the request.