Abstract: A combination model combining a velocity regression method (V-reg) with the modified ANNIE model may be used to predict the stiffness coefficients, Ci,j, in a transversely isotropic medium without using the Stoneley wave velocity. The stiffness coefficients may be used to characterize the surrounding formation, which may be used in hydraulic fracture modeling, stage/perforation design, and well completion operations (e.g., perforating and fracturing operations).

Abstract: In accordance with embodiments of the present disclosure, a simplified geomechanical model that considers the anisotropic (e.g., directional) properties of a formation and the presence of natural fractures in the formation is provided. A system and method may be designed according to the present disclosure to create a simplified geomechanical model of a horizontally laminated formation that includes pre-existing natural fractures. The simplified geomechanical model can be used to calculate the fracture closure pressure of the formation and to design a fracturing operation for injecting fracture fluid into the formation, thus improving the efficiency of a subterranean operation. The disclosed model may provide a more realistic model for fractured shales than an isotropic or vertically transverse isotropic (VTI) model. In addition, the disclosed model may be simpler to implement than a full orthorhombic model.

Abstract: Systems and methods for identifying formation layer boundaries on well log measurements using a second derivative of the last iteratively smoothed well log measurements and a fluctuation index to determine the extent of smoothing.

Abstract: A method to minimize borehole effects upon a multi-component induction tool within a well and borehole with water-based mud includes measuring parameters of the reservoir with the induction tool to create an array of measured components. The method further includes comparing a measured component from the array of measured components with a corresponding model component from an array of model components for a reservoir model with known parameters and no borehole effects, and determining the parameters for the reservoir based upon the comparison of the measured component and the corresponding model component.

Abstract: In accordance with some embodiments of the present disclosure, a geomechanical model of the stresses on an orthorhombic media for use during a subterranean operation is disclosed. The method includes retrieving a stiffness coefficient matrix for a formation to be fractured and generating a geomechanical model of the formation based on a set of natural fractures and an anisotropic behavior of the formation. The method additionally includes calculating a mechanical property of the formation based on the model and the stiffness coefficient matrix. The method further includes fracturing the formation with a fracturing fluid, a pressure of the fracturing fluid based on the mechanical property.

Abstract: In some embodiments, a method and apparatus, as well as an article, may operate to estimate a property of an earth formation by generating at least one shale model to represent an earth formation comprised of a non-zero percentage of shale. The shale model includes two curves to represent a relationship between a porosity parameter and a pulsed neutron measurement at two different corresponding percentages of gas saturation, respectively. A matrix model representing an earth formation with 0% shale is combined with one or more shale models to create a formation model. Measured pulsed neutron data is compared with the formation model to estimate a property of the earth formation. Additional apparatus, systems, and methods are disclosed.

Abstract: In some embodiments, a method for transposition of logs onto a horizontal well path may include collecting vertical situational data from a plurality of depths of a vertical well in a geological formation and collecting horizontal situational data from a plurality of locations along the horizontal well path in the geological formation. The method further includes collecting geological data associated with the plurality of depths of the vertical well and generating pseudo-logs for the horizontal well path based on the plurality of depths and the associated geological data for the plurality of depths.

Abstract: A method that includes obtaining log data of a downhole formation, and characterizing the downhole formation by determining stiffness coefficients including C33, C44, C66, C11, C12, and C13. C13 is a function of C33, C44, C66, and at least one of a kerogen volume and a clay volume derived from the log data. In another method or system, C13 is derived based at least in part on C11 calculated as C11=k1[C33+2(C66?C44)]+k2 or C33 calculated as C33=((C11?k2)/k1)?2(C66?C44), where k1 and k2 are predetermined constants. In another method or system, C13 is derived in part from at least one of a kerogen volume derived from the log data, a clay volume derived from the log data, C11 calculated as C11=k1[C33+2(C66?C44)]+k2, or C33 calculated as C33=((C11?k2)/k1)?2(C66?C44), where k1 and k2 are predetermined constants.

Abstract: Systems and methods for identifying formation layer boundaries on well log measurements using a second derivative of the last iteratively smoothed well log measurements and a fluctuation index to determine the extent of smoothing.

Abstract: Disclosed embodiments include systems and methods of correcting induction logging data for relative dip. Initial induction logging data is measured at a plurality of frequencies. One example embodiment includes displaying dip corrected data for a plurality of different relative dip angles, which may further be displayed with a qualitative indicator displayed over many depth samples for selecting or validating a correct relative dip angle. The data may be iteratively processed using an automated relative dip correction algorithm and analyzed by the user to obtain and apply the best relative dip correction angle to induction logging data. Once dip corrected, the induction logging data can be used with resistivity methodologies generally designed for instances where no dip is present in the formation under analysis.

Abstract: A method that includes obtaining log data of a downhole formation, and characterizing the downhole formation by determining stiffness coefficients including C33, C44, C66, C11, C12, and C13. C13 is a function of C33, C44, C66, and at least one of a kerogen volume and a clay volume derived from the log data. In another method or system, C13 is derived based at least in part on C11 calculated as C11=k1[C33+2(C66?C44)]+k2 or C33 calculated as C33=((C11?k2)/k1)?2(C66?C44), where k1 and k2 are predetermined constants. In another method or system, C13 is derived in part from at least one of a kerogen volume derived from the log data, a clay volume derived from the log data, C11 calculated as C11=k1[C33+2(C66?C44)]+k2, or C33 calculated as C33=((C11?k2)/k1)?2(C66?C44), where k1 and k2 are predetermined constants.

Abstract: A system and method for determining kerogen porosity of a formation for downhole operations is described herein. The method includes calculating a first formation characteristic and a second formation characteristic at a processor of an information handling system. The method further includes determining a kerogen porosity of the formation based, at least in part, on the first formation characteristic and the second formation characteristic. And the method also includes performing a downhole operation based, at least in part, on the determined kerogen porosity.