Abstract: An acoustic source for delivering acoustic energy to a ground formation, particularly a rock formation, the source including (a) a solenoid to generate an electromagnetic field, (b) a bullet positioned within the influence of the electromagnetic field, (c) a casing surrounding and enclosing the solenoid and bullet so that both the solenoid and the bullet are protected from the surrounding environment, in use the solenoid being electrically energized to cause the bullet to be propelled by electromagnetic force so that the bullet impacts an anvil portion of the casing in contact with the ground formation is provided.

Abstract: An acoustic source for delivering acoustic energy to a ground formation, particularly a rock formation, the source including (a) a solenoid to generate an electromagnetic field, (b) a bullet positioned within the influence of the electromagnetic field, (c) a casing surrounding and enclosing the solenoid and bullet so that both the solenoid and the bullet are protected from the surrounding environment, in use the solenoid being electrically energized to cause the bullet to be propelled by electromagnetic force so that the bullet impacts an anvil portion of the casing in contact with the ground formation is provided.

Abstract: The invention includes, in its various aspects and embodiments, a method and apparatus for multiplexing data on-bit in a drilling operation. The apparatus comprises a bit; a plurality of transducers situated on the bit; and an analog multiplexer situated on the on the bit and capable of receiving the output of the transducers, multiplexing the received outputs, and transmitting the multiplexed outputs. The method comprises taking a plurality of measurements of at least one down-hole drilling condition at a bit of a drill string; generating a plurality of analog signals representative of the measurements; and multiplexing the analog signals at the bit.

Abstract: Disclosed is a method of measuring stick slip in an earth drilling system, and a system for performing same. The method includes positioning an accelerometer in a downhole component of a drill string, the accelerometer being radially offset from a centerline of the downhole component, obtaining acceleration data for the drill string during drilling operations using the accelerometer and determining if the drill string has experienced stick slip based upon mean acceleration values obtained by analyzing the acceleration data obtained using the accelerometer.

Abstract: The present invention is directed to a housing for equipment that may be employed in obtaining downhole measurement data. In one illustrative embodiment, the apparatus comprises a first component adapted to be positioned in a subterranean hole, a second component adapted to be positioned in the subterranean hole, and a detachable housing, at least a portion of which is clamped between the first and second components, the housing having at least one cavity formed therein and at least one device positioned within the at least one cavity.

Abstract: The invention includes, in its various aspects and embodiments, a method and apparatus for multiplexing data on-bit in a drilling operation. The apparatus comprises a bit; a plurality of transducers situated on the bit; and an analog multiplexer situated on the on the bit and capable of receiving the output of the transducers, multiplexing the received outputs, and transmitting the multiplexed outputs. The method comprises taking a plurality of measurements of at least one down-hole drilling condition at a bit of a drill string; generating a plurality of analog signals representative of the measurements; and multiplexing the analog signals at the bit.

Abstract: The present invention is generally directed to a tool for obtaining downhole measurements and methods of using such a tool. In one illustrative embodiment the tool comprises a body, at least one strain gauge cavity in the body, the strain gauge cavity having a strain gauge mounting surface that is located at a position such that a region of approximately zero strain due to at least one downhole operating condition exists on the mounting surface when the tool is subjected to downhole operating conditions, and a strain gauge operatively coupled to the mounting face above the region of approximately zero strain.

Abstract: The present invention is generally directed to a tool for obtaining weight-on-bit (WOB) measurements and methods of using such a tool. In one illustrative embodiment the tool comprises a body, at least one strain gauge cavity in the body, the strain gauge cavity having a strain gauge mounting surface that is located at a position such that a region of approximately zero axial strain due to downhole pressures during drilling operations exists on the mounting surface when the tool is subjected to downhole pressures during drilling operations, and a weight-on-bit strain gauge operatively coupled to the mounting face above the region of approximately zero axial strain.

Abstract: An accelerometer caliper while drilling arrangement comprising a drill bit having an axis of rotation and a gauge region, a caliper tool body, a first accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit.

Abstract: An accelerometer caliper while drilling arrangement comprising a drill bit having an axis of rotation and a gauge region, a caliper tool body, a first accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit.