Abstract: Methods and systems are disclosed. The methods may include determining a first sequence of permeabilities by subjecting a rock sample to a first sequence of confining stress, axial stress, pore pressure (CSASPP) triplets and determining a first rock parameter using the first sequence of permeabilities, the first sequence of CSASPP triplets, and a first permeability model. The methods may further include determining a second sequence of permeabilities by subjecting the rock sample to a second sequence of CSASPP triplets and determining a second rock parameter using the second sequence of permeabilities, the second sequence of CSASPP triplets, and the first permeability model. The method may still further include determining an in situ permeability for an in situ rock based on an initial permeability, a second stress sensitivity parameter, a first stress sensitivity parameter, a confining stress value, axial stress values, a pore pressure value, and a second permeability model.

Abstract: Methods and systems are disclosed. The methods may include determining a first sequence of permeabilities by subjecting a rock sample to a first sequence of confining stress, axial stress, pore pressure (CSASPP) triplets and determining a first rock parameter using the first sequence of permeabilities, the first sequence of CSASPP triplets, and a first permeability model. The methods may further include determining a second sequence of permeabilities by subjecting the rock sample to a second sequence of CSASPP triplets and determining a second rock parameter using the second sequence of permeabilities, the second sequence of CSASPP triplets, and the first permeability model. The method may still further include determining an in situ permeability for an in situ rock based on an initial permeability, a second stress sensitivity parameter, a first stress sensitivity parameter, a confining stress value, axial stress values, a pore pressure value, and a second permeability model.

Abstract: A method and system for determining an uncorrupted NMR response from a sample at a predetermined measurement pressure is provided. The method includes obtaining a sample and a filler fluid with a negligible NMR response, determining a volume of filler fluid based on a dimension of the sample and an interior volume of a pressure cell, injecting the volume of filler fluid at a first temperature into the pressure cell and then changing the temperature of the volume of the filler fluid to a second temperature. The method also includes inserting the sample into the volume of filler fluid within the pressure cell, displacing an upper surface of filler fluid to a predetermined level within the interior volume of the pressure cell. The method still further includes establishing the predetermined measurement pressure within the pressure cell and determining the uncorrupted NMR response from the sample at the predetermined measurement pressure.

Abstract: A method and system for determining an uncorrupted NMR response from a sample at a predetermined measurement pressure is provided. The method includes obtaining a sample and a filler fluid with a negligible NMR response, determining a volume of filler fluid based on a dimension of the sample and an interior volume of a pressure cell, injecting the volume of filler fluid at a first temperature into the pressure cell and then changing the temperature of the volume of the filler fluid to a second temperature. The method also includes inserting the sample into the volume of filler fluid within the pressure cell, displacing an upper surface of filler fluid to a predetermined level within the interior volume of the pressure cell. The method still further includes establishing the predetermined measurement pressure within the pressure cell and determining the uncorrupted NMR response from the sample at the predetermined measurement pressure.

Abstract: Methods and systems for separating mud from drill cuttings are disclosed. The method includes collecting drill cuttings from a shale shaker or a wellhead, placing the drill cuttings in a fluid that matches the fluid in the drilling mud, and filtering the drill cuttings through a sieve having a first mesh size. The method further includes placing the filtered drill cuttings in a sieve basket having a second mesh size, wherein the second mesh size is smaller than the first mesh size, placing the sieve basket in a vessel, and adding the fluid to completely submerge the drill cuttings in the fluid. The method also includes placing the vessel including the sieve basket, the drill cuttings, and the fluid in a sonicator-shaker, and simultaneously sonicating and shaking the vessel to separate the drill cuttings from contaminants thereon.

Abstract: A mounting device for holding a sample mounted to a sample holder for use in an inverted microscope. The mounting device includes a platen; a mounting located on a sample side of the platen; a sample holder removably coupled to the mounting so the sample is along an optical axis of the inverted microscope; and a spacer shaped as a hollow prism or a hollow cylinder having a height and defining a through hole. The platen is disposed on the spacer with the sample side facing toward the spacer and the sample holder positioned within the through hole. The height of the spacer arranges the sample within a focal plane of the inverted microscope.

Abstract: Methods for determining reservoir characteristics of a well can include receiving a first core from the well; performing an experiment to determine the wave velocity associated with a first direction of the first core, the experiment including: transmitting an ultrasonic wave through the first core in the first direction; receiving the transmitted ultrasonic wave; and determining a directional wave velocity of the first core based on the transmitted ultrasonic wave and the received transmitted ultrasonic wave, wherein the directional wave velocity represents a wave velocity along the first direction; rotating the first core about a longitudinal axis of the first core; and performing the experiment along a second direction of the first core.

Abstract: Methods, systems, and computer-readable medium to perform operations for identifying fracture barriers in a well. The operations include converting rebound hardness values of a rock specimen from the well to unconfined compressive strength (UCS) values, where each of the rebound hardness values corresponds to a respective coordinate of a measurement grid imposed on the specimen. The operations further include, for each column of the grid, plotting the UCS values versus depth. Further, the operations include mapping, based on a maximum UCS value and a minimum UCS value, a relative strength contour plot for the specimen. Yet further, the operations include mapping, based on a fixed strength range, an absolute strength contour plot for the specimen. In addition, the operations include determining, based on the relative strength contour, the absolute strength contour, and mineralogy of the rock specimen, that the rock specimen is indicative of a fracture barrier in the well.

Abstract: Methods for determining reservoir characteristics of a well can include receiving a first core from the well; performing an experiment to determine the wave velocity associated with a first direction of the first core, the experiment including: transmitting an ultrasonic wave through the first core in the first direction; receiving the transmitted ultrasonic wave; and determining a directional wave velocity of the first core based on the transmitted ultrasonic wave and the received transmitted ultrasonic wave, wherein the directional wave velocity represents a wave velocity along the first direction; rotating the first core about a longitudinal axis of the first core; and performing the experiment along a second direction of the first core.

Abstract: A mounting device for holding a sample mounted to a sample holder for use in an inverted microscope. The mounting device includes a platen; a mounting located on a sample side of the platen; a sample holder removably coupled to the mounting so the sample is along an optical axis of the inverted microscope; and a spacer shaped as a hollow prism or a hollow cylinder having a height and defining a through hole. The platen is disposed on the spacer with the sample side facing toward the spacer and the sample holder positioned within the through hole. The height of the spacer arranges the sample within a focal plane of the inverted microscope.

Abstract: Methods and systems for separating mud from drill cuttings are disclosed. The method includes collecting drill cuttings from a shale shaker or a wellhead, placing the drill cuttings in a fluid that matches the fluid in the drilling mud, and filtering the drill cuttings through a sieve having a first mesh size. The method further includes placing the filtered drill cuttings in a sieve basket having a second mesh size, wherein the second mesh size is smaller than the first mesh size, placing the sieve basket in a vessel, and adding the fluid to completely submerge the drill cuttings in the fluid. The method also includes placing the vessel including the sieve basket, the drill cuttings, and the fluid in a sonicator-shaker, and simultaneously sonicating and shaking the vessel to separate the drill cuttings from contaminants thereon.

Abstract: Methods and systems for detecting impact of induced micro-fractures in a subsurface formation are disclosed. The method includes determining an unloading effective stress (?ul) in a formation sample taken from a wellbore drilled into the subsurface formation, determining a fracture closure stress (?cl) of the formation sample, determining that the unloading effective stress (?ul) is greater than or equal to the fracture closure stress (?ul), and in response to determining that unloading effective stress (?ul) is greater than or equal to the fracture closure stress (?ul), operating the well system to inhibit impact of micro-fractures in the wellbore.

Abstract: Methods, systems, and computer-readable medium to perform operations for identifying fracture barriers in a well. The operations include converting rebound hardness values of a rock specimen from the well to unconfined compressive strength (UCS) values, where each of the rebound hardness values corresponds to a respective coordinate of a measurement grid imposed on the specimen. The operations further include, for each column of the grid, plotting the UCS values versus depth. Further, the operations include mapping, based on a maximum UCS value and a minimum UCS value, a relative strength contour plot for the specimen. Yet further, the operations include mapping, based on a fixed strength range, an absolute strength contour plot for the specimen. In addition, the operations include determining, based on the relative strength contour, the absolute strength contour, and mineralogy of the rock specimen, that the rock specimen is indicative of a fracture barrier in the well.

Abstract: Methods and systems for detecting impact of induced micro-fractures in a subsurface formation are disclosed. The method includes determining an unloading effective stress (?ul) in a formation sample taken from a wellbore drilled into the subsurface formation, determining a fracture closure stress (?cl) of the formation sample, determining that the unloading effective stress (?ul) is greater than or equal to the fracture closure stress (?ul), and in response to determining that unloading effective stress (?ul) is greater than or equal to the fracture closure stress (?ul), operating the well system to inhibit impact of micro-fractures in the wellbore.