Abstract: Systems and methods for determining optimal perforation orientations for hydraulic fracturing of wells in a subterranean formation are presented. The method comprises identifying in-situ stresses for a portion of a well bore formed and transforming the in-situ stresses between coordinate systems. Pressure coefficients and a breakdown pressure for each trial perforation phase angle at a perforation cluster determined, and a perforation point in the well bore coordinate system is calculated for each trial perforation phase angle of the perforation cluster. The perforation point in the well bore coordinate system is transformed to the translated global coordinate system for each trial perforation phase angle. A target perforation phase angle is selected at a minimum breakdown pressure for the perforation cluster, and a perforation azimuth and perforation dip is calculated for the perforation cluster at the minimum breakdown pressure for the target perforation phase angles.

Abstract: A system and method for performing a reservoir evaluation are disclosed. The method includes obtaining a nuclear magnetic resonance (NMR) dataset for a plurality of samples and obtaining an NMR log for a wellbore penetrating a reservoir. The method further includes determining a rock facies description for each sample, determining an NMR transverse relaxation time (NMR T2) distribution from the NMR dataset, and determining a set of parameters characterizing the NMR T2 distribution based on one or more predetermined parameters. The method still further includes identifying a plurality of NMR facies based, at least in part, on the set of parameters for each sample, determining a transformation that maps a subset of rock facies to a subset of the plurality of NMR facies, and performing the reservoir evaluation based, at least in part, on applying the transformation to the NMR log.

Abstract: A method for modeling compaction in a reservoir including obtaining a profile of vertical burial depth, a profile of effective stress against the vertical burial depth, and approximating a plurality of rock grains with a hexagonal closed-packed arrangement of spheres to estimate compacted mechanical and chemical porosity profiles.

Abstract: A system and method for performing a reservoir evaluation are disclosed. The method includes obtaining a nuclear magnetic resonance (NMR) dataset for a plurality of samples and obtaining an NMR log for a wellbore penetrating a reservoir. The method further includes determining a rock facies description for each sample, determining an NMR transverse relaxation time (NMR T2) distribution from the NMR dataset, and determining a set of parameters characterizing the NMR T2 distribution based on one or more predetermined parameters. The method still further includes identifying a plurality of NMR facies based, at least in part, on the set of parameters for each sample, determining a transformation that maps a subset of rock facies to a subset of the plurality of NMR facies, and performing the reservoir evaluation based, at least in part, on applying the transformation to the NMR log.

Abstract: A rapid mining method for sandstone-type uranium resources in a uranium and coal superposed area, which relates to the technical field of mining engineering is provided. The method includes: arranging a high-density adjustable well pattern in an in-situ leaching mining area; determining a length and a position of a filter located on the in-situ leaching mining area through a digital well construction technology; and in a production stage, carrying out operations such as pumping/injection centralized filtration, intensified leaching, high-intensity extraction, high-intensity injection, and change of layout of the high-density adjustable well pattern to rapidly obtain sandstone-type uranium resources in a uranium and coal superposed area. A recovery speed of the sandstone-type uranium resources can be improved, and service life of the in-situ leaching mining area can be shortened.

Abstract: Techniques for hydraulic fracturing a subsurface formation can include using a deterministic model to simulate a deviated well comprising a casing and at least one perforation tunnel. The techniques can include determining a different statistical distribution for each of one or more parameters to the deterministic model. The statistical distributions can be determined from the log data along the measured depth within the wellbore. The techniques can include probabilistically solving the deterministic model to determine a mean and a standard deviation of breakdown pressures along the measured depth within the wellbore. The techniques can include processing the mean and the standard deviation of breakdown pressures to determine an upper bound breakdown pressure based on a level of confidence. The techniques can include drilling and completing a deviated well based on the determined upper bound breakdown pressure and injecting hydraulic fluid to cause hydraulic fracturing of the subsurface formation.

Abstract: The present disclosure relates to a method and a system for determining a well spacing for in-situ leaching mining of a high-permeability sandstone-type uranium/copper deposit.

Abstract: A method for evaluating reservoir quality of a carbonate rock includes: acquiring a thin section of the carbonate rock with a predetermined thickness; obtaining a microscopic image of the thin section; analyzing the microscopic image of the thin section to determine a content of one or more components of the carbonate rock selected from a group of calcite, pore space, replacive dolomite, dolomite cement, and matrix; and calculating a change of porosity based on the content of the one or more components.

Abstract: Systems and methods for determining perforation orientations of a subterranean formation for a hydraulic fracturing treatment are presented. The method comprises identifying in-situ stresses for a portion of a wellbore formed from a terranean surface into a subterranean formation. The method also includes transforming the in-situ stresses from a global coordinate system to a wellbore coordinate system at a perforation cluster of the wellbore that comprises at least one perforation tunnel for a hydraulic fracturing treatment. The in-situ stresses are transformed from the wellbore coordinate system to a perforation coordinate system through at least one rotation matrix. Pressure coefficients and a breakdown pressure for each trial perforation phase angle at a perforation cluster determined, and a perforation point in the wellbore coordinate system is calculated for each trial perforation phase angle of the perforation cluster.

Abstract: Methods of estimating permeability of reservoir rocks using mercury injection capillary pressure can include: receiving mercury injection capillary pressure test data and porosity data for a core sample; determining a fractal dimension (D) for the core sample based on the received mercury injection capillary pressure test data for the core sample; determining a pore throat radius (Rd) for the core sample; determining a composite parameter (?) for the core sample where ? = ? ? R d ( D - 2 ) ; and estimating permeability (K) of the core sample based on a relationship of ln(K) as a function of ln(?) determined by performing a regression analysis data from other core samples from the reservoir.

Abstract: A method of rock typing includes obtaining mercury injection capillary pressure (MICP) data regarding a region of interest. A distance matrix is computed for distributions determined from the MICP data using a statistical distance metric. A cluster tree of the distributions is generated using the distance matrix. The cluster tree is adjusted based on a petrographic characteristic to produce an adjusted cluster tree, which is used to determine a pore structure types of the region of interest.

Abstract: Techniques for hydraulic fracturing a subsurface formation can include using a deterministic model to simulate a deviated well comprising a casing and at least one perforation tunnel. The techniques can include determining a different statistical distribution for each of one or more parameters to the deterministic model. The statistical distributions can be determined from the log data along the measured depth within the wellbore. The techniques can include probabilistically solving the deterministic model to determine a mean and a standard deviation of breakdown pressures along the measured depth within the wellbore. The techniques can include processing the mean and the standard deviation of breakdown pressures to determine an upper bound breakdown pressure based on a level of confidence. The techniques can include drilling and completing a deviated well based on the determined upper bound breakdown pressure and injecting hydraulic fluid to cause hydraulic fracturing of the subsurface formation.

Abstract: Techniques for determining a breakdown pressure of a subterranean formation include identifying in-situ stresses for a portion of a wellbore formed into a subterranean formation; transforming the in-situ stresses (and induced stresses) from a global coordinate system to a wellbore coordinate system of a deviated portion of the wellbore that includes at least one perforation tunnel for a hydraulic fracturing treatment; transforming the in-situ stresses from the wellbore coordinate system to a perforation coordinate system through at least one rotation matrix; determining one or more stresses at a wellbore-perforation interface of the perforation tunnel from the in-situ stresses in the perforation coordinate system; calculating one or more hoop stresses at a perforation tunnel wall of the perforation tunnel from the determined stresses on the wellbore-perforation interface; and determining a breakdown pressure for the subterranean formation based on the calculated one or more hoop stresses and an effect of casi

Abstract: Methods of estimating permeability of reservoir rocks using mercury injection capillary pressure can include: receiving mercury injection capillary pressure test data and porosity data for a core sample; determining a fractal dimension (D) for the core sample based on the received mercury injection capillary pressure test data for the core sample; determining a pore throat radius (Rd) for the core sample; determining a composite parameter (?) for the core sample where ? = ? ? R d ( D - 2 ) ; and estimating permeability (K) of the core sample based on a relationship of ln(K) as a function of ln(?) determined by performing a regression analysis data from other core samples from the reservoir.

Abstract: A method of rock typing includes obtaining mercury injection capillary pressure (MICP) data regarding a region of interest. A distance matrix is computed for distributions determined from the MICP data using a statistical distance metric. A cluster tree of the distributions is generated using the distance matrix. The cluster tree is adjusted based on a petrographic characteristic to produce an adjusted cluster tree, which is used to determine a pore structure types of the region of interest.