Methods and systems for determining caving volume estimations based on logging data and geomechanical models are provided. For example, a system can receive image log data measured during a drilling operation in a wellbore. The system can receive an identification of a breakout in a subterranean formation around the wellbore. The system can determine, using the image log data, a breakout angular width for the breakout. The system can determine a breakout depth for the breakout. The system can determine a caving volume based on the breakout depth and the breakout angular width substantially contemporaneously with the drilling operation. The system can output the caving volume estimation for use in substantially contemporaneously adjusting a drilling parameter for the drilling operation.

An apparatus and method of operating a drilling system with a directional guidance system and a drilling operation system is described. The directional guidance system and drilling operation system may engage in bi-directional communication during a slide drilling operation. This communication may be continual during the drilling operation. Parameters of the drilling instructions and the drilling operation system may be changed in response to these communications resulting in new instructions and changed slide drilling operations.

An apparatus and method of operating a drilling system with a directional guidance system and a drilling operation system is described. The directional guidance system and drilling operation system may engage in bi-directional communication during a slide drilling operation. This communication may be continual during the drilling operation. Parameters of the drilling instructions and the drilling operation system may be changed in response to these communications resulting in new instructions and changed slide drilling operations.

Rate of penetration (ROP) measurement system (10) has sensor apparatus on a drill rig detecting drilling advancement. Sender (38, 200) transmits to a receiver (40, 204), optionally via a reflector (39, 208). An electronic sub (201) can include the sender (200), receiver (204) or reflector (208). Reflector (39, 208) reflects signals to the receiver (40, 204). Distance measurement or space mapping can use LIDAR/laser and MEMS mirror. Releasable attachment to the drill rig can be by magnet (112). Atmospheric or barometric pressure can be detected and pressure change can be used to determine distance moved. WOB, RPM, torque and time rate of progress can be measured and combined with distance moved measurements to assess wear on a drill bit. Near real time

ROP measurement can be calculated and displayed (17) and/or reported (21). Drilling efficiency and premature drill wear or change in rock can be determined.

Rate of penetration (ROP) measurement system (10) has sensor apparatus on a drill rig detecting drilling advancement. Sender (38, 200) transmits to a receiver (40, 204), optionally via a reflector (39, 208). An electronic sub (201) can include the sender (200), receiver (204) or reflector (208). Reflector (39, 208) reflects signals to the receiver (40, 204). Distance measurement or space mapping can use LIDAR/laser and MEMS mirror. Releasable attachment to the drill rig can be by magnet (112). Atmospheric or barometric pressure can be detected and pressure change can be used to determine distance moved. WOB, RPM, torque and time rate of progress can be measured and combined with distance moved measurements to assess wear on a drill bit. Near real time

ROP measurement can be calculated and displayed (17) and/or reported (21). Drilling efficiency and premature drill wear or change in rock can be determined.

Drilling system and methods may employ a weight-on-bit optimization for an existing drilling mode and, upon transitioning to a different drilling mode, determine an initial weight-on-bit within a range derived from: a sinusoidal buckling ratio, a helical buckling ratio, and the weight-on-bit value for the prior drilling mode. The sinusoidal buckling ratio is the ratio of a minimum weight-on-bit to induce sinusoidal buckling in a sliding mode to a minimum weight-on-bit to induce sinusoidal buckling in a rotating mode, and the helical buckling ratio is the ratio of a minimum weight-on-bit to induce helical buckling in the sliding mode to a minimum weight-on-bit to induce helical buckling in the rotating mode. The ratios are a function of the length of the drill string and hence vary with the position of the drill bit along the borehole.

Drilling system and methods may employ a weight-on-bit optimization for an existing drilling mode and, upon transitioning to a different drilling mode, determine an initial weight-on-bit within a range derived from: a sinusoidal buckling ratio, a helical buckling ratio, and the weight-on-bit value for the prior drilling mode. The sinusoidal buckling ratio is the ratio of a minimum weight-on-bit to induce sinusoidal buckling in a sliding mode to a minimum weight-on-bit to induce sinusoidal buckling in a rotating mode, and the helical buckling ratio is the ratio of a minimum weight-on-bit to induce helical buckling in the sliding mode to a minimum weight-on-bit to induce helical buckling in the rotating mode. The ratios are a function of the length of the drill string and hence vary with the position of the drill bit along the borehole.

The method for drilling includes extending a borehole from a surface location to a borehole end with a drill string having a bottom hole assembly with a drill bit. A surface sensor and a downhole sensor take measurements used to project borehole features, like the borehole end. The measurements are used to project the borehole end so that the drill bit can be steered through the rock formation. The downhole sensor is separated from the bit location by a plurality of segments. The method includes corrections when the measurements at the downhole location are not the measurements at the bit location. As the drill bit travels, the types of corrections change, including applying an initial Kalman filter, a first adjusted Kalman filter, a second adjusted Kalman filter, and a third adjusted Kalman filter, according to the plurality of segments between the downhole sensor and the bit location.

The method for drilling includes extending a borehole from a surface location to a borehole end with a drill string having a bottom hole assembly with a drill bit. A surface sensor and a downhole sensor take measurements used to project borehole features, like the borehole end. The measurements are used to project the borehole end so that the drill bit can be steered through the rock formation. The downhole sensor is separated from the bit location by a plurality of segments. The method includes corrections when the measurements at the downhole location are not the measurements at the bit location. As the drill bit travels, the types of corrections change, including applying an initial Kalman filter, a first adjusted Kalman filter, a second adjusted Kalman filter, and a third adjusted Kalman filter, according to the plurality of segments between the downhole sensor and the bit location.

A method for determining a real-time pore pressure log of a well in a reservoir, including the steps: storing existing data logs of surface drilling parameters, logging while drilling (LWD), and mud gas of existing wells in a database, storing existing pore pressure logs of the existing wells in the database, wherein the existing pore pressure logs correspond to the existing data logs, determining a relationship between the existing data logs and the existing pore pressure logs, drilling a new well into the reservoir, determining new data logs of surface drilling parameters, LWD, and mud gas of the new well while drilling the new well, inputting the new data logs of the new well into the relationship while drilling the new well, determining a real-time pore pressure log of the new well by outputting an estimated pore pressure at a certain depth by the relationship while drilling the new well.