Abstract: A method for evaluating and controlling a washout region of a wellbore placed in a formation includes: obtaining information about the wellbore and the formation; establishing a washout indicator function as a function of time and location; computationally determining whether the washout region exists by calculating the washout indicator function on a cross section of the wellbore and the formation, at each depth in a specific depth range; and upon finding presence of the washout region in the specific depth range, quantifying the washout region. The washout indicator function returns: a negative value for a point within the formation; a positive value for a point within the washout region; and zero for a point on a boundary.

Abstract: Methods and systems include obtaining a correlation and obtaining a salt sample from a salt formation. The methods and systems further include, for each of N cycles, exposing, using an injection system, the salt sample to an nth amount of a gas and determining an nth value of a property by subjecting the salt sample, using an atomic force microscopy (AFM) system, to an AFM test. The methods and systems further include determining a relationship using the N values of the property, determining, using the correlation, a macroscale relationship based on the relationship, and generating a fit constitutive model by fitting the constitutive model to the macroscale relationship. The methods and systems include generating a model of a salt cavern within the salt formation based on the fit constitutive model and designing a salt cavern for withdrawal cycles of the gas using the model.

Abstract: A method for subsurface sequestration of carbon dioxide includes placing into a subterranean zone an oxidizer having a redox potential of at least 0.5 volts. The subterranean zone has an average total organic content of at least three weight percent. Carbon dioxide is injected into the subterranean zone via one or a plurality of wells. A total volume of all fluids injected into the subterranean zone via the one or the plurality of wells includes, on average per well per month, at least sixty-five weight percent carbon dioxide and less than thirty weight percent water.

Abstract: Techniques for determining an uptake capacity of a core sample include measuring a nuclear magnetic resonance (NMR) spectrum signal of a test fluid at a particular pressure and entrained in a core sample enclosed in a test cylinder of an NMR pressure cell such that an annulus is defined between the core sample and the test cylinder; deconvolving the NMR spectrum signal into a first NMR spectrum signal portion that is associated with a first portion of the test fluid in the annulus and a second NMR spectrum signal portion that is associated with a second portion of the test fluid entrained in the core sample; and determining a mass of the second portion of the test fluid based at least in part on the first and second NMR spectrum signals.

Abstract: Systems and methods for determining breakdown overpressure are disclosed. The methods may include obtaining a borehole radius and a porosity value in a borehole; determining a rock brittleness index value from the porosity value; determining a breakdown overpressure radius from the rock brittleness index value and the borehole radius; and determining a breakdown overpressure from the breakdown overpressure radius. The methods may further include planning a fracking operation in a well based on the determined breakdown overpressure.

Abstract: Unconventional hydrocarbon source rock reservoirs can contain the organic material kerogen, intertwined with the rock matrix. The kerogen can alter the tensile strength of the rock and contribute to higher fracture energy needs. To degrade kerogen and other organic materials, oxidizing gasses are dissolved in carbon dioxide (CO2) which is then used as part of a fracturing fluid. The oxidizing gasses can be dissolved directly in the CO2 or generated in situ using precursors.

Abstract: Techniques for determining an uptake capacity of a core sample include measuring a nuclear magnetic resonance (NMR) spectrum signal of a test fluid at a particular pressure and entrained in a core sample enclosed in a test cylinder of an NMR pressure cell such that an annulus is defined between the core sample and the test cylinder; deconvolving the NMR spectrum signal into a first NMR spectrum signal portion that is associated with a first portion of the test fluid in the annulus and a second NMR spectrum signal portion that is associated with a second portion of the test fluid entrained in the core sample; and determining a mass of the second portion of the test fluid based at least in part on the first and second NMR spectrum signals.

Abstract: Hydraulic fracturing fluids and methods to hydraulically fracture a subterranean formation and oxidize organic material in the subterranean formation. The hydraulic fracturing fluid includes water, another fluid, and a surfactant. An inorganic oxidizer is included in the water.

Abstract: An apparatus for determining a carbon sequestration characteristic of a geological material includes a sample holder within an inner chamber and a pressure pump configured to apply a confining pressure to the inner chamber, a first pressure gauge and a second pressure gauge configured to measure a fluid pressure at the fluid inlet and a fluid pressure at the fluid outlet, respectively, and a carbon dioxide pump configured to inject carbon dioxide into the inner chamber via the fluid inlet. The apparatus further includes a separator for separating a volume of carbon dioxide from fluid flowing from the fluid outlet, and a return line configured to return at least a portion of the volume of carbon dioxide separated by the separator to the fluid inlet.

Abstract: A method includes obtaining total stresses and pore pressures of each porous medium of a formation, determining a first and second set of effective stresses for the formation, determining an individual collapse and fracturing mud weight for each porous medium of the formation using a first set of associated failure criteria, wherein the first set of associated failure criteria are based on the first set of effective stresses, determining an overall collapse and fracturing mud weight for the formation using a second set of associated failure criteria, wherein the second set of associated failure criteria is based on the second set of effective stresses, determining a mud weight window for the formation using the individual collapse mud weight, the individual fracturing mud weight, the overall collapse mud weight, and the overall fracturing mud weight, and transmitting a command to a drilling system based on the mud weight window.

Abstract: A method for subsurface sequestration of carbon includes injecting a treatment composition comprising a mineralization accelerant into a subterranean zone at least partially saturated with saline water. The mineralization accelerant is reactive with carbon dioxide to form bicarbonate. The method further includes injecting carbon in the form of carbon dioxide into the subterranean zone and sequestering at least a portion of the carbon in the subterranean zone by precipitation in the subterranean zone of a carbonate mineral formed from reaction of the bicarbonate with metal cations dissolved in the saline water. At least a portion of the bicarbonate is formed by reaction of the mineralization accelerant with the carbon dioxide.

Abstract: A computer-implemented method for quantitative prediction and sorting of carbon underground treatment and sequestration is described. The method includes preprocessing multiple data sets, wherein the multiple datasets are multi-modal and multiscale data sets. The method also includes predicting geological structural properties, chemical properties, and geological properties by inputting the preprocessed multiple data sets into trained machine learning models. Additionally, the method includes ranking the storage and treatment potential of a formation based on the predicted geological structural properties, chemical properties, and geological properties.

Abstract: The subject matter of this specification can be embodied in, among other things, a method for treating a geologic formation that includes providing a hydraulic fracture model, providing a first value representative of a volume of kerogen breaker in a fracturing fluid, determining a discrete fracture network (DFN) based on the hydraulic fracture model and the first value, determining a geomechanical model based on the DFN and a reservoir model based on the DFN, determining a hydrocarbon production volume based on the geomechanical model and the reservoir model, adjusting the first value based on the hydrocarbon production volume, and adjusting a volume of kerogen breaker in the fracturing fluid to a hydrocarbon reservoir based on the adjusted first value.

Abstract: A method for subsurface sequestration of carbon dioxide includes placing into a subterranean zone an oxidizer having a redox potential of at least 0.5 volts. The subterranean zone has an average total organic content of at least three weight percent. Carbon dioxide is injected into the subterranean zone via one or a plurality of wells. A total volume of all fluids injected into the subterranean zone via the one or the plurality of wells includes, on average per well per month, at least sixty-five weight percent carbon dioxide and less than thirty weight percent water.

Abstract: Systems and methods for predicting a breakdown pressure of a formation and fracturing the formation account for filter cake effects. The systems and methods measure a time-dependent permeability and a time-dependent thickness of a filter cake formed by a first drilling mud. The systems and methods determine a time-dependent permeability model and a time-dependent thickness model of the filter cake. The systems and methods select a breakdown pressure model based on (i) the time-dependent thickness of the filter cake, (ii) the time-dependent permeability of the filter cake, and (iii) the permeability of the formation. The systems and methods use the selected breakdown pressure model to predict the breakdown pressure of the formation and fracture the formation using a drilling fluid having a mud weight associated with the predicted breakdown pressure of the formation.

Abstract: Systems and methods for predicting a breakdown pressure of a formation and fracturing the formation account for filter cake effects. The systems and methods measure a time-dependent permeability and a time-dependent thickness of a filter cake formed by a first drilling mud. The systems and methods determine a time-dependent permeability model and a time-dependent thickness model of the filter cake. The systems and methods select a breakdown pressure model based on (i) the time-dependent thickness of the filter cake, (ii) the time-dependent permeability of the filter cake, and (iii) the permeability of the formation. The systems and methods use the selected breakdown pressure model to predict the breakdown pressure of the formation and fracture the formation using a drilling fluid having a mud weight associated with the predicted breakdown pressure of the formation.

Abstract: Systems and methods for determining a connected porosity and a non-connected porosity in a fluid-saturated hydrocarbon reservoir are disclosed. The methods include obtaining at least one rock sample from the fluid-saturated hydrocarbon reservoir, determining, using a petrophysical sample analyzer, at least one petrophysical parameter of the rock sample, and measuring at least one of an elastic wave velocity and an elastic wave attenuation for each of a plurality of wave frequencies. The methods further include determining, using a computer processor, the connected porosity and the non-connected porosity of the rock sample using a dual-porosity single-permeability model based, at least in part, on at least one petrophysical parameter and at least one of the elastic wave velocity and the elastic wave attenuation.

Abstract: A method for subsurface sequestration of carbon includes injecting a treatment composition comprising a mineralization accelerant into a subterranean zone at least partially saturated with saline water. The mineralization accelerant is reactive with carbon dioxide to form bicarbonate. The method further includes injecting carbon in the form of carbon dioxide into the subterranean zone and sequestering at least a portion of the carbon in the subterranean zone by precipitation in the subterranean zone of a carbonate mineral formed from reaction of the bicarbonate with metal cations dissolved in the saline water. At least a portion of the bicarbonate is formed by reaction of the mineralization accelerant with the carbon dioxide.

Abstract: A method for subsurface sequestration of carbon dioxide includes placing into a subterranean zone an oxidizer having a redox potential of at least 0.5 volts. The subterranean zone has an average total organic content of at least three weight percent. Carbon dioxide is injected into the subterranean zone via one or a plurality of wells. A total volume of all fluids injected into the subterranean zone via the one or the plurality of wells includes, on average per well per month, at least sixty-five weight percent carbon dioxide and less than thirty weight percent water.

Abstract: A method of determining rock matrix and fracture permeability to perform a reservoir fluid flow simulation. The method includes: obtaining a petrophysical characterization of a formation sample, measuring a first and second elastic wave velocity of the formation sample at a first and second frequency, calculating an average rock matrix density and an average porosity of the formation sample, determining a set of calculated elastic wave velocities for the first and second frequencies over a range of candidate permeabilities, and determining a rock matrix permeability and a fracture permeability based on the set of calculated elastic wave velocities at the first and second frequency respectively. The method further including performing a reservoir fluid flow simulation based, at least in part, on at least one of the rock matrix permeability and the fracture permeability.