Abstract: In accordance with one or more embodiments of the present disclosure, a host-guest lost circulation material (LCM) composition for sealing lost circulation zones in wellbores includes an aqueous solution; one or more linear polymer chains, the linear polymer chains comprising polyethylene glycols (PEG) with molecular weights greater than 2500 g/mol, polypropylene glycols (PPG), polydimethylsiloxanes (PDMS), or combinations thereof; and one or more cyclic molecules comprising alpha cyclodextrin, beta cyclodextrin, gamma cyclodextrin, or combinations thereof, and wherein the one or more cyclic molecules form a host-guest structure around the one or more linear polymer chains utilizing van der Waals forces.

Abstract: In accordance with one or more embodiments of the present disclosure, a host-guest lost circulation material (LCM) composition for sealing lost circulation zones in wellbores includes an aqueous solution; one or more linear polymer chains, the linear polymer chains comprising polyethylene glycols (PEG) with molecular weights greater than 2500 g/mol, polypropylene glycols (PPG), polydimethylsiloxanes (PDMS), or combinations thereof; and one or more cyclic molecules comprising alpha cyclodextrin, beta cyclodextrin, gamma cyclodextrin, or combinations thereof, and wherein the one or more cyclic molecules form a host-guest structure around the one or more linear polymer chains utilizing van der Waals forces.

Abstract: Methods for determining an in-situ pore pressure in a formation rock may include acquiring well log data, calculating a cation-exchange capacity, calculating a mole fraction of fixed charges using the cation-exchange capacity, determining a formation temperature, calculating the in-situ pore pressure, outputting the in-situ pore pressure of the formation rock, and using the in-situ pore pressure in a wellbore stability model to monitor and maintain stability of the formation rock. Corresponding electronic devices may include a computer processor coupled to at least one logging tool, wherein the logging tool is configured to acquire well log data in a formation rock. Non-transitory computer storage mediums may include program instructions, that when executed, may be configured to perform the methods for determining an in-situ pore pressure in a formation rock.

Abstract: Systems and methods for determining shear failure of a rock formation are disclosed. The method includes receiving, by a processor, a plurality of parameters related to physical properties of the rock formation, applying the plurality of parameters to a predetermined failure criterion, and determining shear failure of the rock formation based on the failure criterion. In some embodiments the failure criterion is a modified Hoek-Brown failure criterion that takes into consideration an intermediate principal stress, and the difference between normal stresses and an average confining stress.

Abstract: Methods for determining an in-situ pore pressure in a formation rock may include acquiring well log data, calculating a cation-exchange capacity, calculating a mole fraction of fixed charges using the cation-exchange capacity, determining a formation temperature, calculating the in-situ pore pressure, outputting the in-situ pore pressure of the formation rock, and using the in-situ pore pressure in a wellbore stability model to monitor and maintain stability of the formation rock. Corresponding electronic devices may include a computer processor coupled to at least one logging tool, wherein the logging tool is configured to acquire well log data in a formation rock. Non-transitory computer storage mediums may include program instructions, that when executed, may be configured to perform the methods for determining an in-situ pore pressure in a formation rock.

Abstract: Systems and methods for determining shear failure of a rock formation are disclosed. The method includes receiving, by a processor, a plurality of parameters related to physical properties of the rock formation, applying the plurality of parameters to a predetermined failure criterion, and determining shear failure of the rock formation based on the failure criterion. In some embodiments the failure criterion is a modified Hoek-Brown failure criterion that takes into consideration an intermediate principal stress, and the difference between normal stresses and an average confining stress.

Abstract: A method for predicting mechanical properties of a transverse isotropic region of a rock formation traversed by a well bore including running a logging tool in the well bore; the mass percentages of minerals present in the rock formation surrounding the well bore are measured with the logging tool. The density of the minerals present in the rock formation surrounding the well bore is determined. The porosity of the rock formation surrounding the well bore is measured. From the porosity and the measured mass percentages and density of the minerals, all the transverse isotropic elastic coefficients of the rock formation are determined in real time.

Abstract: A method for predicting mechanical properties of a transverse isotropic region of a rock formation traversed by a well bore including running a logging tool in the well bore; the mass percentages of minerals present in the rock formation surrounding the well bore are measured with the logging tool. The density of the minerals present in the rock formation surrounding the well bore is determined. The porosity of the rock formation surrounding the well bore is measured. From the porosity and the measured mass percentages and density of the minerals, all the transverse isotropic elastic coefficients of the rock formation are determined in real time.

Abstract: A test cell and method for stress testing a test specimen including a first platen and a second platen. Each platen having a loading surface, an inclined surface, and a longitudinal axis. The inclined surface being inclined relative to the longitudinal axis at an angle and the inclined surface having a specimen recess formed therein for receiving a portion of the test specimen such that when the inclined surface of the second platen is positioned in a face-to-face relationship with the inclined surface of the first platen, a shear stress is applied to the test specimen when an axial load is applied to the first and second platens. The platens further including fluid ports to subject the test specimen to fluid flow at various pressures and fluid chemistries and ultrasonic transducers to determine acoustic, compressional, and shear wave velocities and in multiple orientations.

Abstract: A test cell and method for stress testing a test specimen including a first platen and a second platen. Each platen having a loading surface, an inclined surface, and a longitudinal axis. The inclined surface being inclined relative to the longitudinal axis at an angle and the inclined surface having a specimen recess formed therein for receiving a portion of the test specimen such that when the inclined surface of the second platen is positioned in a face-to-face relationship with the inclined surface of the first platen, a shear stress is applied to the test specimen when an axial load is applied to the first and second platens. The platens further including fluid ports to subject the test specimen to fluid flow at various pressures and fluid chemistries and ultrasonic transducers to determine acoustic, compressional, and shear wave velocities and in multiple orientations.