Stabilizer for use in a drill string

A stabilizer for use in a drill string for drilling a bore hole, and through which a drilling fluid flows, comprising:

• a) a stabilizer body adapted to be mounted in said drill string;
• b) a sleeve rotatably mounted on said stabilizer body;
• c) a stabilizer blade projecting radially outward from said sleeve;
• d) a movable locking member, said locking member locking said sleeve into a first circumferential orientation when said locking member is in a first position and unlocking said sleeve when said locking member is in a second position, whereby said sleeve can rotate around said stabilizer body when unlocked;
• e) a first piston coupled to said locking member, whereby actuation of said first piston drives said locking member from said first position to said second position, wherein said first piston is actuated by pressure applied by said drilling fluid to said first piston;
• f) means for intensifying the pressure applied to said first piston by said drilling fluid, wherein said pressure intensifying means comprises a second piston.

A stabilizer for use in a drill string for drilling a bore hole, comprising:

• a) a stabilizer body adapted to be mounted in said drill string;
• b) a sleeve rotatably mounted on said stabilizer body;
• c) a stabilizer blade projecting radially outward from said sleeve, said stabilizer blade having a distal end;
• d) a pad mounted in said distal end of said stabilizer blade, said pad having first and second ends, a pivot joint pivotally coupling said pad first end to said blade distal end, whereby rotation of said pad about said pivot joint in a first direction displaces said pad second end radially outward so as to contact said bore hole wall.

A drill string for use in drilling a bore hole in an earthen formation, said bore hole having a wall, comprising:

• a) a drill bit;
• b) means for rotating said drill bit in the clockwise direction so as to drill a bore hole in an earthen formation;
• c) a stabilizer mounted proximate said drill bit, said stabilizer comprising a housing and a stabilizer blade extending radially outward from said housing, said blade having a distal end;
• d) a sensor pad mounted in said distal end of said blade, said sensor pad having first and second ends, said second end being circumferentially displaced from said first end in the clockwise direction, whereby said second end forms a leading edge when said drill string rotates in said clockwise direction, a pivot joint pivotally coupling said first end of said sensor pad to said blade distal end whereby rotation of said sensor pad about said pivot joint in a counterclockwise direction displaces said sensor pad second end radially outward so as to contact and apply a force to said bore hole wall, said contact creating a friction force when said drill string rotates in said clockwise direction that tends to further rotate said sensor pad about said pivot joint in said counterclockwise direction thereby increasing said force applied by said sensor pad second end to said bore hole wall;
• e) a sensor mounted in said sensor pad for sensing a property of said formation.

An apparatus for use in a drill string for sensing a property of an earthen formation through which said drill string drills a bore hole when said drill string is rotated in a first circumferential direction, said bore hole having a wall, comprising:

• a) a housing adapted to be mounted in a drill string;
• b) a blade extending radially outward from said housing, said blade having a distal end;
• c) a sensor pad mounted in said distal end of said blade, said sensor pad having a circumferentially trailing first end and a circumferentially leading second end when said housing is rotated in the clockwise direction, a pivot joint pivotally coupling said first end of said sensor pad to said blade distal end whereby rotation of said sensor pad about said pivot joint in a counterclockwise direction displaces said sensor pad second end radially outward so as to contact and apply a force to said bore hole wall, said contact creating a friction force when said housing rotates in said clockwise direction that tends to further rotate said sensor pad about said pivot joint in said counterclockwise direction thereby increasing said force applied by said sensor pad second end to said bore hole wall;
• d) at least a first sensor mounted in said sensor pad for sensing a property of said formation.