Systems and methods for determining mechanical properties of anisotropic media are disclosed. A method for determining mechanical properties of an anisotropic media includes obtaining log data of the anisotropic media, the log data corresponding to measurements of the anisotropic media collected with a logging tool; determining values for a plurality of first stiffness components of a stiffness matrix based on horizontal and vertical velocities derived from the log data; determining an upper bound for a second stiffness component of the stiffness matrix based on the values for the plurality of first stiffness components; estimating a value for the second stiffness component based on the determined upper bound; determining a mechanical property of the anisotropic media based on the estimated value of the second stiffness component; and providing the determined mechanical property.

A method of designing a cement blend for a wellbore isolation barrier based on the analysis of a stress state of the wellbore isolation barrier from the injection of CO.sub.2 into a porous formation. The analysis software may determine an optimized cement blend for a future CO.sub.2 injection schedule. The analysis software may determine a current near wellbore stress state for a current CO.sub.2 injection schedule. The analysis software may optimize a CO.sub.2 injection schedule based on the analysis of a future near wellbore stress state of the wellbore isolation barrier. The near wellbore stress state of the isolation barrier may be determined by at least one model accessed by the analysis software. The inputs into the model comprise periodic CO.sub.2 injection pressure and flowrate datasets, cement properties, and formation properties.

Disclosed is a method for determining three-dimensional in-situ stress based on displacement measurement of borehole wall, including the following steps: selecting a testing borehole section for in-situ stress testing; arranging 6-9 measurement points in the testing borehole section; using a coring drill to perform a radial cut around the displacement measurement device to relieve the stress at the measurement point; cutting off the drilled core by the coring drill; recovering the sidewall coring device and removing the cores, and then measuring the elastic deformation parameters of each core; The beneficial effect of the technical scheme proposed in this disclosure is: the method provided by this disclosure overcomes the disadvantage that the measurement can only be performed at the bottom of a borehole and thus it has a wider application range.

Disclosed are methods, systems, and computer-readable medium to perform operations including: determining a state of in-situ earth stresses around a wellbore located in a formation; transforming the in-situ earth stresses from a global Cartesian coordinate system to a local wellbore coordinate system; calculating, based on the transformed in-situ earth stresses in the local wellbore coordinate system, principal stresses around the wellbore; generating, using a failure criterion that incorporates (i) principal stresses, (ii) mud weight, and (iii) rock strength, a function for calculating a rock compressive failure; and predicting, using the function, a failure zone around the wellbore.

A pressure testing system for analyzing a rock formation includes a tubular support member sized to pass into a wellbore of the rock formation and an adjustable loading device configured to exert a radial load against the wall of the wellbore. The adjustable loading device includes multiple expandable members distributed around a circumference of the tubular support member and configured to expand to respectively exert multiple radial pressures against the wall of the wellbore that together provide the radial load. The pressure testing system further includes a control module configured to selectively control expansion of each expandable member of the multiple expandable members to vary the radial load exerted by the adjustable loading device as a function of an angle around the circumference of the tubular support member.

The present invention relates to a method of detection of hydrocarbon horizontal slippage passages comprising the following steps: (a.) slippage passage data acquisition and identification; (b.) slippage passage prediction; (c.) slippage passage characterization; (d.) slippage passage calibration; and (e.) slippage passage parameterization and modelling. The present invention also relates to the use of such a method for positioning a well bore for hydrocarbon production.

A method for classifying a subterranean formation includes rotating an ultrasonic logging tool in a borehole penetrating a formation. The ultrasonic logging tool includes an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body. The ultrasonic logging tool measures an azimuthal shear slowness image and an azimuthal compressional slowness image while rotating in the borehole. The images are evaluated to classify the homogeneity/heterogeneity and isotropy/anisotropy of the formation.

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.

A method of testing mechanical properties of an earth formation can include disposing a probe in a wellbore, impacting the probe against a wall of the wellbore, and measuring a parameter related to at least one of a displacement, displacement rate, strain, and strain rate, of at least one of the probe and the formation. Another method can include disposing a probe and a known material in a wellbore, and after the disposing, penetrating the known material with the probe. Another method can include disposing a probe in a wellbore, measuring a displacement of the probe into a wall of the wellbore while measuring a load applied to the probe, and applying fluid pressure to the formation via the probe.

A method for setting a wellbore casing in a subterranean formation is described. The method includes: drilling a test wellbore in the subterranean formation; generating a density profile of a plurality of geological layers above a salt formation in the subterranean formation based on observations from the test wellbore; calculating an overburden stress imposed on the salt formation by weight of overlying formation based on the density profile of the plurality of geological layers; performing creep mechanical behavior tests on core samples from the salt formation to generate a strain-time curve for the salt formation; calibrating multiple analytical creep models with mechanical properties of the salt data generated by the creep mechanical behavior tests; implementing a wellbore closure model based on a best-fit analytical model and mechanical properties of the multiple analytical creep models; drilling a well; and setting a casing through the salt formation.