Stall detection and recovery for mud motors
AssigneeHelmerich & Payne, Inc.
InventorsFergus Hopwood, Christopher Robert Novosad
Life of this patent
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Abstract
A system and method for stall recovery of mud motors may be implemented in a steering control system. The stall recovery system and method may involve automatic detection of a stall of a mud motor during drilling controlled by the steering control system, and may respond to the stall in a rapid and controlled manner to avoid or minimize damage to the mud motor, such as by immediately reducing mud pressure and stopping rotary drilling, if used, faster than a typical human operator could perform. The stall recovery system and method may further take actions to automatically restart drilling.
Claims24
A method for detecting a stall of a mud motor during drilling, the method comprising:
- providing a drilling mud to a mud motor from a drilling mud system during drilling of a wellbore to a drill bit powered by the mud motor;
- providing a plurality of differential pressure values of the drilling mud to a stall detection system;
- providing a plurality of rate of penetration (ROP) values of the drill string to the stall detection system;
- determining, in real-time during drilling by the stall detection system, at least one of (i) that a differential pressure value is at or above a first threshold value for a minimum of a first predetermined time period, or (ii) the differential pressure value increases to a second threshold value within a second predetermined time period, wherein both the first and the second threshold values are based on a percentage value above a continuous operating pressure rating for the mud motor;
- determining, by the stall detection system, that a ROP value decreases during the first predetermined time period or a rate of change of the ROP value decreases during the first predetermined time period;
- responsive to the determining, detecting and providing an indication of a stall when at least one of (i) the differential pressure value is at or above the first threshold value for the minimum of the first predetermined time period, or (ii) the differential pressure value increases to the second threshold value within the second predetermined time period and at least one of (i) the ROP value decreases during the period of time or (ii) the rate of change of the ROP value decreases during the period of time;
- in response to determining the indication of a stall, initiating a recovery operation comprising sending a first signal causing performance of one or more of the following:
- cease rotation of a drill string to which a mud motor is attached;
- cease pumping drilling mud into a borehole.
A method for recovering from a mud motor stall, the method comprising:
- providing an indication of a mud motor stall by at least determining that a differential pressure value increases over a period of time and (i) ROP value decreases during the period of time or (iii) a rate of change of the ROP value decreases during the period of time;
- and
- providing an automated stall recovery system, wherein the automated stall recovery system in response to an indication of the mud motor stall performs the following steps:
- when the indication of the mud motor stall occurs during rotary drilling of a borehole, controlling a top drive on a drilling rig that is rotary drilling a wellbore to cease rotation of a drill string to which a mud motor is attached;
- controlling a mud pump to cease pumping drilling mud into the borehole;
- controlling a release of any residual torque in the drill string;
- controlling a release of pressure in the drilling mud;
- controlling a hoisting of the drill string off bottom by a predetermined amount;
- controlling the mud pump to restart pumping of the drilling mud;
- controlling the top drive to restart rotation of the drill string if the indication of the mud motor stall occurred during rotary drilling;
- and
- controlling a resumption of engaging a drill bit with a formation being drilled.
A non-transitory, computer-readable medium storing a plurality of instruction that, when executed by one or more processors of a computing device, cause the one or more processors to perform operations for detecting a stall of a mud motor during drilling, comprising:
- sending a signal to a drilling system to provide a drilling mud to a mud motor from a drilling mud system during drilling of a wellbore to a drill bit powered by the mud motor;
- receiving a plurality of differential pressure values of the drilling mud;
- receiving a plurality of rate of penetration (ROP) values of the drill string;
- determining that the differential pressure value increases over a period of time;
- determining that a ROP value decreases during the period of time or a rate of change of the ROP value decreases during the period of time;
- responsive to the determining, detecting and providing an indication of a stall when the differential pressure value increases during the period of time, and (i) the ROP value decreases during the period of time or (ii) the rate of change of the ROP value decreases during the period of time
- in response to detecting the indication of a stall, initiating a recovery operation comprising sending a first signal causing performance of one or more of the following:
- ceasing rotation of a drill string to which a mud motor is attached;
- ceasing pumping drilling mud into a borehole.
Dependencies are inferred from the claim text.