Downhole motor assembly and method for torque regulation
AssigneeHalliburton Energy Services, Inc.
InventorsRichard T. Hay, Victor Gawski
Life of this patent
Estimating the term…
Abstract
A downhole motor assembly for driving a drill bit. The assembly includes a hydraulic drive section with a stator and a rotor located inside the stator to form a flow path between the stator and the rotor. Fluid flowing through the flow path in response to a pressure differential across the hydraulic drive section creates an operative force to rotate the drill bit. The assembly also includes a regulation mechanism that includes a valve and a fluid flow diversion bore for diverting at least some fluid from the flow path when the pressure differential across the hydraulic drive section is greater than or equal to a transition pressure differential.
Claims17
A downhole motor assembly for driving a drill bit to form a borehole, the downhole motor assembly including:
- a hydraulic drive section operatively connected to the drill bit and a drill string, the hydraulic drive section including a stator and a rotor located inside the stator, the stator and rotor forming a flow path between the stator and the rotor such that fluid flowing through the flow path in response to a pressure differential across the hydraulic drive section creates an operative force to rotate the drill bit;
- and
- a regulation mechanism including a valve and a fluid flow diversion bore for diverting at least some fluid from the flow path when the pressure differential across the hydraulic drive section is greater than or equal to a transition pressure differential, wherein the fluid flow diversion bore extends radially outward through the stator to an annulus between the drill string and a sidewall of the borehole.
A method of drilling a subterranean wellbore using a drill bit including:
- applying an operative force to the drill bit using a downhole motor assembly, the downhole motor assembly coupled to a drill string and including:
- a hydraulic drive section including a stator and a rotor located inside the stator, the stator and rotor forming a flow path between the stator and the rotor;
- and
- a regulation mechanism including a valve and a fluid flow diversion bore extending radially outward through the stator to an annulus between the drillstring and a sidewall of the wellbore;
- where applying the operative force includes flowing fluid through the flow path to create the operative force;
- decreasing the amount operative force on the drill bit when the pressure differential across the hydraulic drive section is greater than or equal to a transition pressure differential by operating the regulation mechanism to divert at least some fluid from the flow path and into the fluid flow diversion bore;
- and
- maintaining at least some operative force on the drill bit while diverting fluid flow.
A subterranean wellbore drilling system including:
- a drill bit connected with a drill string;
- and
- a downhole motor assembly within the drill string for driving the drill bit, the downhole motor assembly including:
- a hydraulic drive section operatively connected to the drill bit, the hydraulic drive section including a stator and a rotor located inside the stator, the stator and rotor forming a flow path between the stator and the rotor such that fluid flowing through the flow path in response to a pressure differential across the hydraulic drive section creates an operative force to operate the drill bit;
- and
- a regulation mechanism including a valve and a fluid flow diversion bore for diverting at least some fluid from the flow path when the pressure differential across the hydraulic drive section is greater than or equal to a transition pressure differential, wherein the fluid flow diversion bore extends radially outward through the stator to an annulus between the drill string and a sidewall of the wellbore.
Dependencies are inferred from the claim text.