Abstract: A method can include acquiring real-time data during rig operations that include rig operations for drilling a borehole in a subsurface geologic region using a drillstring that includes a drill bit, where the drillstring includes connected stands of drill pipe, and where the real-time data include a measured post-connection hook load value; predicting a post-connection hook load value using a trained model; estimating a post-connection hook load value using a filter that includes an input for the measured post-connection hook load value and an input for the predicted post-connection hook load value; and controlling drilling of the borehole based at least in part on the estimated post-connection hook load value.

Abstract: A method can include acquiring real-time data during rig operations that include rig operations for drilling a borehole in a subsurface geologic region using a drillstring that includes a drill bit, where the drillstring includes connected stands of drill pipe, and where the real-time data include a measured post-connection hook load value; predicting a post-connection hook load value using a trained model; estimating a post-connection hook load value using a filter that includes an input for the measured post-connection hook load value and an input for the predicted post-connection hook load value; and controlling drilling of the borehole based at least in part on the estimated post-connection hook load value.

Abstract: A method can include acquiring data for rig operations that move a drillstring in a borehole in a subsurface geologic region, where the drillstring includes connected stands of drill pipe and a drill bit for drilling into the subsurface geologic region, and where the data include measured depth data, inclination data, mud density data, and measured hook load data; generating an estimated hook load value for a measured depth in the borehole using at least a trained model that receives a portion of the data as associated with the measured depth; performing a comparison between the estimated hook load value and a measured hook load value of the measured hook load data as associated with the measured depth; and, based at least in part on the comparison, determining a level of sticking of the drillstring in the borehole.