Abstract: A method and apparatus for estimating one or more formation properties using in-situ measurements conducted at or near a coring location include a coring tool adapted to cut a core sample in a formation, a member having a distal end that engages a borehole wall substantially adjacent the core sample, and a drive device that engages the member to the borehole wall with a force sufficient to estimate formation strength.

Abstract: Estimating formation properties includes a member coupled to a carrier, the member having a distal end that engages a borehole wall location, the distal end having a curved surface having a radius of curvature in at least one dimension about equal to or greater than a borehole radius. A drive device extends the first extendable member with a force sufficient to determine formation strength, and at least one measurement device providing an output signal indicative of the formation property. Articulating couplings may be used to change an angle of extension of the extendable member.

Abstract: Drill bits and methods for sampling sensor data associated with a state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit configured for receiving a data analysis module. The data analysis module comprises at least one sensor, a memory, and a processor. The processor is configured for executing computer instructions to filter information derived from sensor data in the drill bit to develop a piecewise polynomial curve of the sensor data. Filtering information derived from the sensor data comprises approximating a first derivative of a sensor data waveform, calculating a plurality of zeros for the first derivative of the sensor data waveform, and fitting a cubic polynomial between adjacent zeros calculated from the first derivative of the sensor data waveform resulting in a piecewise cubic polynomial.

Abstract: Methods, computer programs, and systems for detecting at least one downhole condition are disclosed. Forces are measured at a plurality of locations along the drillstring. The drillstring includes a drillpipe. At least one of the forces is measured along the drillpipe. At least one downhole condition is detected based, at least in part, on at least one measured force.

Abstract: A downhole load cell calibrated for enhanced accuracy. The load cell may be a dry load cell calibrated by storage of pre-determined temperature and pressure data relative to the load cell based on known loads applied thereto. Thus, surface equipment employed with the load cell may include a computer program that takes advantage of the stored pre-determined information. The computer program may then be employed for calibration of downhole load cell data based on readings from the load cell along with downhole temperature and pressure information.

Abstract: A technique facilitates the measurements of forces, such as forces that result from gravity and acceleration. The system and methodology utilize a plurality of electrodes that cooperate with a movable electrode. By applying appropriate signals to the electrodes, the movable electrode can be levitated in a manner that creates a sensor system able to accurately detect forces resulting from gravity, acceleration and similar causes.

Abstract: Disclosed is a measuring sensor unit for registering one or more rotational parameters of forces that are exerted on a pipe string as it is being rotated into a well by a drilling machine. The measuring sensor unit has a body with a first end portion that is constructed to releasably engage with the end of a drilling machine drive shaft and a second end portion constructed to releasably engage with the end of a pipe string or with a tool that is integrated into a pipe string. Sensors are mounted on the measuring sensor unit and are in wireless communication with a signal transmitter. The sensors register one or more rotational parameters relevant for the rotation of the pipe string.

Abstract: A real-time line management system and associated methods. A line management system for use in conjunction with an operation in a subterranean well includes a line installed in the well during the operation, and a computing device which indicates a used life of the line during the operation. A method of managing a line used in an operation in a subterranean well includes the steps of: installing the line in the well during the operation; and determining a used life of the line while the line is installed in the well. A method of managing a line used in multiple operations in one or more subterranean wells includes the steps of: estimating conditions which will be experienced by the line during a future operation; and predicting before the future operation what a used life of the line will be after the line is used in the future operation.

Abstract: An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electro-mechanical system (NEMS) and a micro electro-mechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole.

Abstract: A testing method and apparatus for ground liquefaction and dynamic characteristics in the original position utilizing a boring hole, wherein the dynamic strength and deformation characteristics of a soil layer against a dynamic repetitive load, in an optional position in the ground can be obtained by a simple method. A measuring cell based on a three-chamber construction is used, and upper and lower soil layers (J1, J3) with an intermediate soil layer (J2) therebetween are alternately subjected to a dynamic repetitive load, and what influence there is on the intermediate soil layer (J2) is investigated from the relation between pressure and displacement.

Abstract: Drill bits and methods for sampling sensor data associated with the state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit body and a shank. The shank further includes a central bore formed through an inside diameter of the shank and configured for receiving a data analysis module. The data analysis module comprises a plurality of sensors, a memory, and a processor. The processor is configured for executing computer instructions to collect the sensor data by sampling the plurality of sensors, analyzing the sensor data to develop a severity index, comparing the sensor data to at least one adaptive threshold, and modifying a data sampling mode responsive to the comparison. A method comprises collecting sensor data by sampling a plurality of physical parameters associated with a drill bit state while in various sampling modes and transitioning between those sampling modes.

Abstract: An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole.

Abstract: A method for measuring true vertical depth in a borehole, the method including: measuring gravitational acceleration in the borehole; and determining the true vertical depth from the measurement.

Abstract: A real-time line management system and associated methods. A line management system for use in conjunction with an operation in a subterranean well includes a line installed in the well during the operation, and a computing device which indicates a used life of the line during the operation. A method of managing a line used in an operation in a subterranean well includes the steps of: installing the line in the well during the operation; and determining a used life of the line while the line is installed in the well. A method of managing a line used in multiple operations in one or more subterranean wells includes the steps of: estimating conditions which will be experienced by the line during a future operation; and predicting before the future operation what a used life of the line will be after the line is used in the future operation.

Abstract: A downhole tool assembly including a sealing device and a sensing device for sensing parameters associated with the operation of the sealing device.

Abstract: A borehole tool including an interferometer, a light source, a chamber containing a sliding weight having a first optical prism, a second optical prism located within the chamber, a tilt measuring device, and a timing device operatively associated with the interferometer. The light source, the interferometer, and the first and second optical prisms are configured to cause light emitted by the light source to form a first beam and a second beam that interfere with each other. The interferometer measures distances traveled by the sliding weight in the upward and downward direction by counting the fringes caused by the interference between the first beam and the second beam. The tilt measuring device measures the angle of the chamber relative to vertical. The influence of friction on the sliding weight's motion is eliminated by comparing the distances traveled by it in its upward and downward path over an equal time interval.

Abstract: The present invention provides methods and apparatus for measuring subterranean strain. The methods and apparatus use fluid expansion principles to compensate for temperature variations and increase the accuracy of the strain measurements. The methods and apparatus contemplate the use of multiple fluid chambers according to some embodiments in order to remove temperature dependence from stress or strain measurements.

Abstract: A method of predicting the failure of a rock formation surrounding a subterranean cavity, including a measuring set of parameters relating to pressure conditions and stresses in the rock formation surrounding the cavity; using the set of parameters to determine a rock strength; determining a first characteristic length relating to the size of the cavity; determining a second characteristic length relating to the grain size of the rock formation surrounding the cavity; using the first and second characteristic lengths to determine a correction for the rock strength; correcting said rock strength; and using a failure criterion and the corrected rock strength to predict a condition under which the rock formation is expected to produce debris. The results of the prediction can be used to monitor wellbore stability while drilling or optimize the production parameters for a hydrocarbon reservoir.

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: A survey tool for use in a wellbore includes a downhole portion having an axis. The downhole portion is adapted to move within the wellbore with the axis generally parallel to the wellbore. The survey tool further includes a first acceleration sensor mounted at a first position within the downhole portion. The first acceleration sensor is adapted to generate a first signal indicative of an acceleration of the first acceleration sensor along the axis. The survey tool further includes a second acceleration sensor mounted at a second position within the downhole portion. The second position is spaced from the first position by a non-zero distance along the axis. The second acceleration sensor is adapted to generate a second signal indicative of an acceleration of the second acceleration sensor along the axis.

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: The invention is directed toward a subsurface gravity measurement device and a method for calibrating the same that includes a tilt meter and a gravity sensor. The method includes associating tilt information produced by the gravity sensor as a function of a relationship between tilt information produced by the tilt meter and a correction parameter. The tilt meter produces tilt data, and the gravity meter produces gravity data, corresponding to the tilt data. The tilt data and gravity data is fitted to a polynomial equation that has a plurality of initial coefficients associated therewith. The initial coefficients includes information concerning the correction parameter. The correction parameter is derived as a function of the initial coefficients.

Abstract: A well pressure and temperature measurement system and method are provided. In a described embodiment, a sensor system includes multiple strain sensors attached to a structure which changes dimensionally in response to well pressure and temperature changes. The strain sensors may be fiber optic sensors. The structure may be tubular and the strain sensors may detect axial and hoop strains in the structure.

Abstract: The device comprises a corer (1, 4) fitted with a flexible diaphragm (2) on its inside face, means (10) for driving the corer into the soil (11), means for breaking up the soil leaving the top orifice of the corer, means for applying axial forces on the diaphragm (2) and on the top face of the soil sample (12) contained in the corer, and means for measuring stresses and deformations to which the sample (12) is subject. While a measurement is being performed, the corer is held stationary in the soil (11).

Abstract: A torque swivel apparatus. The apparatus includes an upper body assembly secured to the lower end of a locking swivel of the type used in wireline operations. The upper body would engage into a lower body, the lower body secured to the drill string at the rotary table. The upper body would provide a pair of milled out wedge portions for accommodating a pair of wedge members in the lower body to engage therein during coupling. The apparatus further includes a plurality of cylinders positioned into the upper body with a piston member secured within each cylinder, so that each of the four faces of the wedge portions of the upper body accommodates a pair of pistons in its wall. The outer face of each of the pistons would make contact with each of the four faces of the wedge members of the lower body when coupling has occurred. The inner face of each of the pistons would mate with a line having fluid, which when acted upon would register force against the piston.

Abstract: A downhole tool that is connectable to a line to be run downhole with the tool includes a housing, a sensor and a mechanism that is located inside the housing. The mechanism is coupled to the sensor to, in response to the detection of the feature by the sensor, generate a tension signal in the line without physically contacting a downhole structure.

Abstract: The present invention provides a method for analysing a well completion system, wherein the method includes receiving data representative of physical characteristics of the completion system and calculating a first change in length of a tube string resulting from a helical buckling effect. The method further includes calculating a second change in length of the tube string resulting from a ballooning effect and calculating a third change in length of the tube string resulting from a slackoff force effect. Upon completion of the calculating steps, the method may output predetermined results therefrom.

Abstract: A device to monitor and quantify the tension and compression forces acting on a well logging instrument string during deployment. The device eliminates the undesirable effects of downhole hydrostatic pressure on the sensors, and eliminates the need for a costly, complex, and high maintenance hydraulic pressure equalizing system in the force gage assembly. The device provides improved measurement accuracy, provides enhanced reliability and longer life of the sensors, and allows lower cost of manufacture and maintenance.

Abstract: The invention provides a method and apparatus for measuring the torque applied to the drum shaft of a hoist. By measuring the torque on the drum shaft, the force or tension on the fast line can be accurately determined. If the force or tension on the dead line is also measured, the forces on the fast line and dead line can be used to determine the force applied to the load. One embodiment of the invention uses a transmission coupled to the drum shaft as a moment arm. The transmission is coupled to a fixed point by a strain-sensing element located some distance from the center of the drum shaft. The distance between the center of the drum shaft and the point along the transmission where the strain-sensing element is mounted provides the moment arm for measuring the torque on the drum shaft. Another embodiment of the invention provides “C”-shaped side plates to support and mount the main bearings of the drum shaft.

Abstract: A sensing system mounted to a mechanical drill pipe swivel of the type which is mounted on a rig housing to a section of drill pipe. The swivel would include an enlarged body portion for securing to a section of drill pipe. There would be provided a first upper circular collar positionable around the outer surface of the swivel, the collar having a first and second halves hinged at a common edge, so that the collar may move to a first open position to be engaged around the body of the swivel and moved to a second closed position to be locked in place around the swivel body. The collar would include an arm member extending from the collar wall on a first end, to a position so that the second end of the arm member is in line with a portion of the drill pipe to which the swivel is engaged. The second end of the arm member would include first and second sensors positioned facing the section of drill pipe.

Abstract: A method for locating placement of a guide stock in a multilateral well wherein the guide stock is properly aligned with the lateral borehole. The method employs an impression packer with a scribed reference line to provide information at the surface regarding the lateral borehole's exact location and orientation with respect to the originally installed whipstock packer. This information is then employed to make up a guide stock and orientation sub to properly orient the diverter face of the guide stock with the lateral borehole. There are tool embodiments for inflating the impression packer to a preset relatively low internal pressure. In one embodiment, the inflation fluid is carried downhole in the tool and is released to the packer on set down pressure, the fluid being drawn back out of the packer upon pick up. In another embodiment, the impression packer is outfitted with an automatically closing valve.

Abstract: The present invention provides a method for improving the quality of a formation fluid sample by taking the sample at a time when the formation fluid composition contains the most favorable portion of hydrocarbons. This task is accomplished by determining in real-time, the composition of the fluid flowing into a downhole tool from the formation. This method determines the optical density of the fluid as the fluid flows through the tool. An optical spectrum is generated from the density measurement. The optical spectrum is compared to a composite spectrum generated from a database of known fluid samples. As a result of the comparisons, there is a determination of the derivations between corresponding features of the two spectra. Adjustments are made to the components of the composite spectrum until the deviations between the two spectra are at an acceptable minimum. Determinations of the fluid composition are made from the composition of the composite spectrum at the minimum deviation.