Abstract: A method can include receiving real-time data during a drilling operation performed by a drillstring that includes a mud motor and a bit characterized by an expected performance profile; determining actual performance of the drillstring based at least in part on the real-time data; predicting degraded performance of the drillstring based at least in part on the real-time data and a mud motor degradation model; and updating the expected performance profile based on a comparison of the actual performance and the degraded performance.

Abstract: Methods, drilling systems, and computer-readable media for evaluating candidate correctional trajectories for a directional drilling well. If the user wishes to investigate alternatives trajectories or trajectories to get a BHA back to a planned trajectory, the computing system allows the user to enter one or more intermediate targets. The computing system generates drilling parameters for the alternative targets and displays them to the user. The user can adjust parameters and intermediate targets, as well as drilling parameters, to investigate a range of possible solutions before selecting an update to the planned trajectory.

Abstract: A method for controlling drilling fluid properties includes receiving one or more measurements representing a drilling efficiency of a drilling rig including a drill bit deployed into a well. A drilling rig circulates a drilling fluid in the well. The method includes determining that the one or more measurements are lower than expected, determining that a property of a subterranean formation in which drill bit is positioned has changed based on one or more measurements, and in response to determining that the subterranean formation has changed, automatically generating a drilling fluid adjustment plan based at least in part on one or more of a drilling fluid inhibition factor or a drilling fluid stability factor.

Abstract: A method can include receiving data for a bottom hole assembly of a drillstring and a drill plan; generating candidate trajectories using at least a portion of the data; generating drill command schedules for the candidate trajectories; ranking the candidate trajectories based at least in part on the drill command schedules; and outputting at least a top ranked candidate trajectory and its corresponding drill command schedule.

Abstract: A method, apparatus, and program product utilize a buffer defined relative to a wellbore trajectory to generate a work zone around a wellbore for use in connection with formation modeling. In some embodiments, for example, a closed curve such as a non-rectangular, polygonal work zone may be defined around a wellbore based upon a buffer that extends generally transverse to the trajectory of a length of a wellbore a predetermined distance. In addition, boundaries may be defined in a work zone to effectively split the work zone into multiple closed curves or polygons in response to user editing, e.g., to create one or more subsurface layers in the work zone. In such instances, points defining a subsurface layer may be shared by adjacent layers such that editing of such points will affect each of the layers sharing such points.

Abstract: A method, apparatus, and program product utilize a buffer defined relative to a wellbore trajectory to generate a work zone around a wellbore for use in connection with formation modeling. In some embodiments, for example, a closed curve such as a non-rectangular, polygonal work zone may be defined around a wellbore based upon a buffer that extends generally transverse to the trajectory of a length of a wellbore a predetermined distance. In addition, boundaries may be defined in a work zone to effectively split the work zone into multiple closed curves or polygons in response to user editing, e.g., to create one or more subsurface layers in the work zone. In such instances, points defining a subsurface layer may be shared by adjacent layers such that editing of such points will affect each of the layers sharing such points.