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 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.

Embodiments provide techniques for using data from a select set of wells to develop correlations between surface-measured properties, downhole coring parameters, and properties typically determined from subsurface measurements (e.g., from logging tool responses, core analysis, or other subsurface measurements). When new wells are drilled, the surface data acquired while drilling and coring parameters used downhole may be used as an input to these correlations in order to predict properties associated with subsurface measurements.

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 method of estimating a depth of a hydrocarbon-water contact of a hydrocarbon reservoir in a structure. The method may include the steps of analysing one or more samples obtained from the structure to generate a relationship relating resistivity to hydrocarbon-water contact depth, obtaining a resistivity measurement of the hydrocarbon reservoir, and estimating the hydrocarbon-water contact depth from the relationship relating resistivity to hydrocarbon-water contact depth and the resistivity measurement of the hydrocarbon reservoir.

A method of estimating a depth of a hydrocarbon-water contact of a hydrocarbon reservoir in a structure. The method may include the steps of analysing one or more samples obtained from the structure to generate a relationship relating resistivity to hydrocarbon-water contact depth, obtaining a resistivity measurement of the hydrocarbon reservoir, and estimating the hydrocarbon-water contact depth from the relationship relating resistivity to hydrocarbon-water contact depth and the resistivity measurement of the hydrocarbon reservoir.

Methods of analyzing the rock content of a geologic formation are provided herein. The methods typically comprise obtaining samples from the formation and subjecting the samples to conditions that will cause the extraction and/or release of one or more volatile compounds from the samples, if present in the samples, and then analyzing the amount of such one or more volatile compounds released/extracted from the sample and then further relating such results to the physical and/or rock content composition of two or more regions of the geologic formation. The results can be used to inform or guide oil and/or gas exploration and/or production operations, such as placement of fracking operations.

A method may include obtaining various well logs or various core samples regarding a geological region of interest. The method may further include determining various permeability values, various porosity values, and various dolomite volume fraction values regarding the geological region of interest using the well logs or the core samples. The dolomite volume fraction values may correspond to a percentage of dolomite in a total mineral volume. The method may further include determining, using the porosity values, various permeability thresholds corresponding to various predetermined reservoir qualities. The method may further include generating, using the permeability thresholds, the permeability values, and the dolomite volume fraction values, a reservoir model including various dolomite boundaries defining the predetermined reservoir qualities. The method may further include determining a hydrocarbon trap prediction using the reservoir model.

A method may include obtaining various well logs or various core samples regarding a geological region of interest. The method may further include determining various permeability values, various porosity values, and various dolomite volume fraction values regarding the geological region of interest using the well logs or the core samples. The dolomite volume fraction values may correspond to a percentage of dolomite in a total mineral volume. The method may further include determining, using the porosity values, various permeability thresholds corresponding to various predetermined reservoir qualities. The method may further include generating, using the permeability thresholds, the permeability values, and the dolomite volume fraction values, a reservoir model including various dolomite boundaries defining the predetermined reservoir qualities. The method may further include determining a hydrocarbon trap prediction using the reservoir model.

A method for evaluating and optimizing scale management at a subsurface for improved well performance may include performing multiple first tests, where each first test combines a first fluid with a second fluid, wherein the first fluid comprises a concentration of a scale inhibitor and a chemistry of additional fluid components. The method may also include identifying an optimal mixture of the first fluid among the first tests, where the optimal mixture comprises a minimum concentration of the scale inhibitor that reduces scale deposition. The method may further include performing a second test that combines the first fluid with the scale inhibitor, the second fluid, and rock. The method may also include evaluating a concentration of the scale inhibitor in aqueous phase after a period of time after initiating the second test. The method may further include identifying a target fluid for use in a field operation at the subsurface.