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US 8,708,066 B2Granted
Dual BHA drilling system
AssigneeSchlumberger Technology Corporation
InventorsJacques Orban, Sami Iskander
Life of this patent
Estimating the term…
Abstract
A drilling apparatus including a drill collar forming part of a primary drilling assembly and having an outward opening groove in the side thereof, and a secondary drilling assembly. The secondary drilling assembly includes a tubular drill string connected at one end to the drill collar, a drilling motor mounted in the drill string, and a drill bit mounted at the other end of the drill string and connected to the drilling motor. The secondary drilling assembly is mounted in the drill collar so as to be movable between a first position in which the drill bit is seated in the groove, and a second position in which the bit projects laterally from the groove in the side of the drill collar.
Claims39
A drilling apparatus, comprising:
- a drill collar forming part of a primary drilling assembly and having an outward opening groove in the side thereof;
- and
- a secondary drilling assembly, comprising:
- a piston slidably mounted in the drill collar, the piston comprising a bypass to allow fluid to pass along the drill collar without moving the piston;
- a tubular drill string connected at one end to the piston;
- a drilling motor mounted in the drill string, the drilling motor comprising a regulator that controls the opening of the bypass according to motor speed;
- and
- a drill bit mounted at the other end of the drill string and connected to the drilling motor;
- wherein the secondary drilling assembly is mounted in the drill collar so as to be movable between a first position in which the drill bit is seated in the groove, and a second position in which the drill bit projects laterally from the groove in the side of the drill collar.
6 more elements
A method of drilling a borehole, comprising:
- using a drilling apparatus comprising:
- a drill collar forming part of a primary drilling assembly and having an outward opening groove in the side thereof;
- and
- a secondary drilling assembly, comprising:
- a tubular drill string connected at one end to the drill collar;
- a drilling motor mounted in the drill string;
- and
- a drill bit mounted at the other end of the drill string and connected to the drilling motor;
- wherein the secondary drilling assembly is mounted in the drill collar so as to be movable between a first position in which the drill bit is seated in the groove, and a second position in which the bit projects laterally from the groove in the side of the drill collar;
- drilling a main borehole;
- positioning the apparatus at a predetermined location in the main borehole;
- operating the secondary drilling assembly so as to advance the drill bit away from the first position and drill laterally into the formation surrounding the main borehole and form a lateral borehole;
- advancing the drill collar while the secondary drilling assembly is drilling into the formation;
- and
- withdrawing the secondary drilling assembly to the first position.
12 more elements
A drilling apparatus, comprising:
- a drill collar forming part of a primary drilling assembly and having an outward opening groove in the side thereof;
- and
- a secondary drilling assembly, comprising:
- a tubular drill string connected at one end to the drill collar;
- a drilling motor mounted in the drill string, the drilling motor comprising a siren including a stator connected to a piston and a rotor mounted adjacent the stator and connected to the drill bit;
- means to urge the rotor into an open position relative to the stator, wherein the means comprise magnets on the rotor and the stator;
- and
- a drill bit mounted at the other end of the drill string and connected to the drilling motor;
- wherein the secondary drilling assembly is mounted in the drill collar so as to be movable between a first position in which the drill bit is seated in the groove, and a second position in which the drill bit projects laterally from the groove in the side of the drill collar.
6 more elements
A drilling apparatus, comprising:
- a drill collar forming part of a primary drilling assembly and having an outward opening groove in the side thereof;
- and
- a secondary drilling assembly, comprising:
- a tubular drill string connected at one end to the drilling collar;
- a drilling motor mounted in the drill string, the drilling motor comprising a siren including a stator connected to the piston and a rotor mounted adjacent the stator and connected to the drill bit;
- means for adjusting the angular position of the rotor and stator as the secondary drilling assembly moves toward the second position, the means comprising a groove in the drill collar defining a cam surface along which a rotor locating key slides as the secondary drilling assembly moves;
- and
- a drill bit mounted at the other end of the drill string and connected to the drilling motor;
- wherein the secondary drilling assembly is mounted in the drill collar so as to be movable between a first position in which the drill bit is seated in the groove, and a second position in which the drill bit projects laterally from the groove in the side of the drill collar.
6 more elements
Dependencies are inferred from the claim text.