Techniques for calibration of a simulation of a subterranean region having complex fracture geometries. Calibration of indeterministic subsurface discrete fracture network models is performed via non-intrusive embedded discrete fracture modeling formulations applied in conjunction with well testing interpretation and numerical simulation. Subterranean fracture networks are characterized dynamically by embedded discrete fracture modeling to accurately and efficiently determine an optimal fracture model.

In a drilling system, a control system coupled to a drilling rig controls a bottom hole assembly (BHA) to drill a borehole through a geological formation along a drilling path. The control system determines a present position of the BHA and calculates a toolface vector to create a convergence path from the present position of the BHA to a desired target path. The control system also receives geological information and compensates the toolface vector to account for an estimated geologic formation drift. The control system causes at least one control parameter to be modified in order to alter a drilling direction of the BHA based on the calculated toolface vector and transmits the at least one control parameter to the drilling rig to target the BHA in accordance with the calculated toolface vector. The control system iteratively performs this process until convergence with the desired target path is achieved.

In a drilling system, a control system coupled to a drilling rig controls a bottom hole assembly (BHA) to drill a borehole through a geological formation along a drilling path. The control system determines a present position of the BHA and calculates a toolface vector to create a convergence path from the present position of the BHA to a desired target path. The control system also receives geological information and compensates the toolface vector to account for an estimated geologic formation drift. The control system causes at least one control parameter to be modified in order to alter a drilling direction of the BHA based on the calculated toolface vector and transmits the at least one control parameter to the drilling rig to target the BHA in accordance with the calculated toolface vector. The control system iteratively performs this process until convergence with the desired target path is achieved.

A drill bit subsystem can include a drill bit, a processor, and a non-transitory computer-readable medium for storing instructions and for being positioned downhole with the drill bit. The instructions of the non-transitory computer-readable medium can include a machine-teachable module and a control module that are executable by the processor. The machine-teachable module can receive depth data and rate of drill bit penetration from one or more sensors in a drilling operation, and determine an estimated lithology of a formation at which the drill bit subsystem is located. The control module can use the estimated lithology to determine an updated location of the drill bit subsystem, and control a direction of the drill bit using the updated location and a drill plan.

A drill bit subsystem can include a drill bit, a processor, and a non-transitory computer-readable medium for storing instructions and for being positioned downhole with the drill bit. The instructions of the non-transitory computer-readable medium can include a machine-teachable module and a control module that are executable by the processor. The machine-teachable module can receive depth data and rate of drill bit penetration from one or more sensors in a drilling operation, and determine an estimated lithology of a formation at which the drill bit subsystem is located. The control module can use the estimated lithology to determine an updated location of the drill bit subsystem, and control a direction of the drill bit using the updated location and a drill plan.

The present disclosure relates to a method that includes generating a first pulse at a first position along a geological formation with a plurality of antennae, wherein the first pulse comprises a Can-Purcell-Meiboom-Gill (CPMG) sequence, and wherein each antenna of the plurality of antennae is configured to generate NMR data via transmitting and receiving pulses into the geological formation.

A method includes deploying a logging tool in a borehole formed in a subsurface formation, the logging tool having a transmitter and a receiver, wherein a condition that is present during logging comprises at least one of a shape of the borehole is non-circular and the logging tool is off-center within the borehole. The method includes emitting, by the transmitter, a signal into subsurface formation and detecting, by the receiver, a response to the signal being propagated through the subsurface formation. The method includes creating, from the response, a borehole image that includes features in the subsurface formation and correcting the features, wherein correcting the features comprises mapping points of a non-circular shape in the borehole image into a plane substantially perpendicular to an axis of the borehole.

A method includes deploying a logging tool in a borehole formed in a subsurface formation, the logging tool having a transmitter and a receiver, wherein a condition that is present during logging comprises at least one of a shape of the borehole is non-circular and the logging tool is off-center within the borehole. The method includes emitting, by the transmitter, a signal into subsurface formation and detecting, by the receiver, a response to the signal being propagated through the subsurface formation. The method includes creating, from the response, a borehole image that includes features in the subsurface formation and correcting the features, wherein correcting the features comprises mapping points of a non-circular shape in the borehole image into a plane substantially perpendicular to an axis of the borehole.

A wellbore trajectory survey, having an ordered plurality of survey points, is acquired. Each of the plurality of survey points has a measured depth, an inclination, and a geographic location of the point in the wellbore corresponding to the survey point. The wellbore trajectory survey is ordered on measured depth. The processor identifies a minimum lateral measured depth (min_LMD), a maximum lateral measured depth (max_LMD). The processor identifies a mid-lateral point (mid_LMP) in the plurality of survey points whose measured depth (mid_LMD) is greater than min_LMD and less than max_LMD.

A wellbore trajectory survey, having an ordered plurality of survey points, is acquired. Each of the plurality of survey points has a measured depth, an inclination, and a geographic location of the point in the wellbore corresponding to the survey point. The wellbore trajectory survey is ordered on measured depth. The processor identifies a minimum lateral measured depth (min_LMD), a maximum lateral measured depth (max_LMD). The processor identifies a mid-lateral point (mid_LMP) in the plurality of survey points whose measured depth (mid_LMD) is greater than min_LMD and less than max_LMD.