Abstract: A while drilling system and method for determining downhole parameters is provided. The system includes a retrievable while drilling tool positionable in a downhole drilling tool, a sensor chassis and at least one sensor. The while drilling tool is positionable in the downhole drilling tool and has a first communication coupler at an end thereof. The sensor chassis is supported in the drilling tool. The sensor chassis has a second communication coupler at an end thereof for operative connection with the first communication coupler. The sensor is positioned in the chassis and is adapted to measure internal and/or external parameters of the drilling tool. The sensor is operatively connected to the while drilling tool via the communication coupler for communication therebetween. The sensor may be positioned in the while drilling tool and retrievable with the drilling tool. Preferably, the system is operable in high temperature and high pressure conditions.

Abstract: Methods, apparatus, and systems for obtaining information regarding a formation, a casing, or fluid within the casing are provided which utilize an interrogator and one or more sensing devices attached to a casing in a wellbore. The interrogator is located within and may be movable inside the wellbore. The sensing device is positioned and fixed in an opening in the casing. The sensing device includes a housing and a sensor with associated electronic circuitry. The interrogator and sensing device include a magnetic coupling therebetween that is operable when the interrogator and sensing device are positioned in close proximity to one another. Preferably, the magnetic coupling is realized by at least one solenoid winding for the interrogator and at least one solenoid winding for the sensing device, which provide a loosely-coupled transformer interface therebetween. The interrogator and sensing device communicate in a wireless manner over the magnetic coupling therebetween.

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: A soil working method and device, in which a drilling rod, to which is fitted at least one drilling tool, is rotated about a rotation axis with a speed using a rotary drive. The drilling rod is simultaneously lowered into a soil area in the direction of the rotation axis using a feed drive and with a feed rate. The drilling rod speed is determined and a control device decreases the feed rate when the drilling rod speed is reduced.

Abstract: An apparatus and related method generate electrical power in a tubular housing, such as a drill collar, disposed in a borehole when drilling fluid flows through the tubular housing. The apparatus includes a stator adapted for being secured within the tubular housing against rotation relative to the tubular housing, a tubular rotor rotatably carried about the stator, and an impeller peripherally affixed to the rotor. The stator has an array of conductive windings therein, and is preferably an alternator stator. The rotor has an array of magnets therein, and is preferably an alternator rotor. Accordingly, drilling fluid flowing through the tubular housing when the apparatus is disposed therein engages the impeller and induces rotation of the rotor about the stator to generate electrical power.

Abstract: Apparatus and methods for determining suitable displacement fluids for use in subterranean cementing operations, and methods of cementing that use such displacement fluids, are provided. Examples of apparatus include apparatus for evaluating fluids. An example of a system is a system for inverting an oleaginous-external/aqueous-internal fluid in a well bore in a subterranean formation.

Abstract: A controller provides an automatic bit protection sequence for an autodriller that can be initiated during the initial stage of set down of the bit within the formation. The automatic protection sequence establishes a setpoint for a parameter of interest (such as weight on bit, ROP, torque) associated with operation of the drilling system and then initiates a gradual increase in that parameter in order to achieve the setpoint. The bit protection sequence may be adjustable so that varying degrees of gradualness may be selected. The controller of the autodriller may also be provided with measured data for torque, rate of penetration (ROP) and/or the differential pressure of the mud motor of the drilling system. Each of these parameters is provided with a predetermined setpoint, and each may be selected as the controlling parameter for operation of the autodriller.

Abstract: An integrated drilling and evaluation system includes a drill string having an interior portion and a drill bit, carried on a lower end, that includes ports for communicating fluid between the interior portion of the drill string and an uncased well bore. A packer, carried above the drill bit, is operable for sealingly closing a well annulus, A tester valve inserted in the drill string is operable for sealingly closing the drill string. The packer and tester valve are cooperatively operable for isolating a subsurface zone of interest. The system includes monitoring means inserted in the drill string for monitoring a parameter of well fluid from the subsurface zone. Once the subsurface zone is isolated, well fluid is communicated into the interior portion of the drill string through the ports of the drill bit, received by the monitoring means, and tested without removing the drill string form the well.

Abstract: One or more components of a wellbore drilling assembly utilize a modular construction to facilitate assembly, disassembly, repair and/or maintenance of a wellbore drilling assembly and/or to extend the overall operating capabilities of the drilling assembly. In one embodiment, a modular construction is used for an APD Device, a motor driving the modular APD Device, a comminution device, and an annular seal. Individual modules can be configure have different operating set points, operating parameters and characteristics (e.g., rotational speeds, flow rates, pressure differentials, etc.) and/or different responses to given environmental factors or conditions (e.g., pressure, temperature, wellbore fluid chemistry, etc.). In one embodiment, the high-pressure seals used in conjunction with the APD Device and/or motor is a hydrodynamic seal that provides a selected leak or flow rates. Optionally, the seal is modular to provide different degrees of leak rates and/or different functional characteristics.

Abstract: An integrated drilling and evaluation system includes a drill string having an interior portion and a drill bit, carried on a lower end, that includes ports for communicating fluid between the interior portion of the drill string and an uncased well bore. A packer, carried above the drill bit, is operable for sealingly closing a well annulus. A tester valve inserted in the drill string is operable for sealingly closing the drill string. The packer and tester valve are cooperatively operable for isolating a subsurface zone of interest. The system includes monitoring means inserted in the drill string for monitoring a parameter of well fluid from the subsurface zone. Once the subsurface zone is isolated, well fluid is communicated into the interior portion of the drill string through the ports of the drill bit, received by the monitoring means, and tested without removing the drill string form the well.

Abstract: A method and apparatus for detecting torsional vibration, or stick-slip, in a drill string while drilling is described. The method comprises sampling a downhole pressure sensor and using embedded filter schemes and algorithms to determine, based on the pressure samples, whether torsional vibration is occurring in the drill string. The method may also include sending a warning signal to the surface of the well. The apparatus comprises a downhole assembly having a downhole receiver and a master controller. The downhole receiver comprises a pressure sensor, filter schemes, and algorithms for detecting torsional vibration. The downhole assembly may also include a downhole transmitter for sending a warning signal to the surface of the well.

Abstract: A formation pressure testing while drilling device on a bottomhole assembly makes measurements of fluid pressure during drilling of a borehole. Based on the pressure measurements, drilling direction can be altered to maintain the wellbore in a desired relation to a fluid contact. Acoustic transmitters and/or receivers on the bottomhole assembly can provide additional information about bed boundaries, faults and gas-water contacts.

Abstract: An automatic drilling system is disclosed which includes an electric servo motor operatively coupled to a winch brake control, a servo controller operatively coupled to the servo motor, and a drum position encoder rotationally coupled to a winch drum. The controller is adapted to operate the servo motor in response to measurements of position made by the encoder so that a selected rate of rotation of the drum is maintained.

Abstract: A downhole valve device (1) in a drill string (14) in a petroleum well (2) and method for maintaining optimal annular fluid velocity and wellbore pressure. The device comprises a valve housing (20) connected between adjacent segments (12, 13) of the drill string. The valve housing is further provided with at least one valve (23) arranged to open and close to the flow of drilling fluid based on measured values of downhole physical parameters or on signals from the surface in order to permit the through-flow of a sufficient volume of drilling fluid necessary to adjust and maintain the annular fluid velocity of the drilling fluid and the wellbore pressure within optimal operating conditions.

Abstract: A closed-loop circulating system for drilling wells has control of the flow rates in and out of the wellbore. Kicks and fluid losses are quickly controlled by adjusting the backpressure. Kick tolerance and tripping margins are eliminated by real-time determination of pore and fracture pressure. The system can incorporate a rotating BOP and can be used with underbalanced drilling.

Abstract: A drilling system includes a pressure sensor disposed on a drill string in the wellbore, the sensor responsive to pressure of a drilling fluid disposed in an annular space between a wall of the wellbore and the drill string, and a processor operatively coupled to the pressure sensor. The processor is adapted to operate a drill string release controller to release the drill string into the wellbore so as to maintain an equivalent density of the drilling fluid substantially at a selected value. A method for automatically drilling a wellbore includes measuring pressure of a drilling fluid in an annular space between a wall of the wellbore and a drill string in the wellbore, and automatically controlling a rate of release of the drill string in response to the measured pressure so as to maintain an equivalent density of the drilling fluid substantially at a selected value.

Abstract: A method for determining formation pressure at a depth region of formations surrounding a borehole, including: keeping track of the time since cessation of drilling at the depth region; deriving formation permeability at the depth region; causing wellbore pressure to vary periodically in time and determining, at the depth region, the periodic and non-periodic component of pressure measured in the formations; determining, using the time, the periodic component and the permeability, the formation pressure diffusivity and transmissibility and an estimate of the size of the pressure build-up zone around the wellbore at the depth region; determining, using the time, the formation pressure diffusivity and transmissibility, and the non-periodic component, the leak-off rate of the mudcake at the depth region; determining, using the leak-off rate, the pressure gradient at the depth region; and extrapolating, using the pressure gradient and the size of the build-up zone, to determine the formation pressure.

Abstract: An obstacle avoidance system for obstacle detection in an opaque material. The system includes at least one electromagnetic signal source adapted to produce an electromagnetic source signal suitable for transmission through the opaque material, at least one electromagnetic signal detector adapted to receive reflected electromagnetic energy signals from discontinuities in the opaque material encountered by the electromagnetic source signal, and a reflected electromagnetic energy signal processor suitable for determining a presence of obstructions and/or strata variations within the opaque material. The system is preferably integral with a head element suitable for traversing the opaque material, for example a subterranean drill bit.

Abstract: A new method for evaluating the efficiency of a sweep for removing cuttings from a borehole in a subterranean formation during a drilling operation. The method evaluates sweep efficiency on a “mass” in versus “mass out” basis. The method uses downhole density readings taken with a pressure-while-drilling tool inserted in the drill string. Measurements of hydrostatic pressure are converted into equivalent circulating density measurements which in turn are used in calculating the sweep efficiency. The method affords real time estimates at the wellsite of the quantity of formation cuttings brought out of a wellbore by a sweep.

Abstract: Tools and methods are provided that determine the acoustic impedance of drilling fluid using reflections from a precise metal disk. Because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape, the first reflection from the metal disk may be used to calibrate the measurement. A method for determining a borehole fluid property includes (i) generating an acoustic signal within a borehole fluid, (ii) receiving reflections of the acoustic signal from the fluid, and (iii) analyzing a reverberation portion of the acoustic signal to determine the property. The analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property.

Abstract: A method of determining an in situ PVT property of a hydrocarbon reservoir fluid that is present in a hydrocarbon-bearing formation layer traversed by a borehole, which method involves the steps of: a) calculating along the hydrocarbon-bearing formation layer the pressure gradient; and b) determining the in situ PVT property from the pressure gradient using an empirical relation that had been obtained by fitting a curve (11) through previously obtained data points (12, 13, 14) having the measured PVT property as a function of the pressure gradient.

Abstract: In accordance with a method of this invention, formation integrity problems are discovered, diagnosed and corrected in successively drilled subterranean well bore intervals. If one or more of well bore fluid outflows, formation fluid inflows or inadequate well bore pressure containment integrity are discovered in a drilled well bore interval, well logs are run and other relevant well bore data is collected in the drilled well bore interval and analyzed to provide a specific treatment using a specific pumpable sealing composition for sealing and increasing the pressure containment integrity of the well bore. Thereafter, the sealing composition is pumped into the drilled well bore interval whereby the well bore interval is sealed or the pressure containment integrity is increased, or both.

Abstract: A hybrid choke control system wherein the traditional choke experience is manifest in auditory and visual feedback mechanisms which are emulated by a digital control system enabling direct control of either position or back pressure associated with an adjustable choke device. The present invention enhances safety and efficiency when used in association with oil field drilling operations and in particular when applied to a device which provides the user with enhanced control capabilities for direction controlling the back pressure and position associated with drilling chokes during down hole operations.

Abstract: The present invention provides methods and systems for making measurements associated with a rock formation including a main borehole, a microborehole extending from the main borehole into the rock formation, and one or more sensing devices positioned and arranged to make a measurement at measurement zones being located in the microborehole. A packer can also be installed in the microborehole dimensioned and arranged to hydraulically isolate the measurement zones from conditions present in other parts of the microborehole and/or main borehole. Methods and systems are also provided for taking fluid samples and injecting fluid tracers in a microborehole.

Abstract: A drill bit is designed to achieve optimum performance in a specified drilling application defined by the drilling system, the formation to be drilled and the configuration of the bore hole. A depth of cut versus predicted torque for a basic bit configuration is evaluated for different configurations of the drill bit. A computer modeling program is used to obtain the predicted torque for the basic bit configuration, and its modifications. Features of the bit design are changed to achieve the lowest predicted torque for an optimum depth of cut. Presenting the computer analysis as depth of cut versus predicted torque for the bit design simplifies the design selection process. The formation being drilled may be evaluated by comparing actual torque with predicted torque for a given rate of penetration. The evaluation can be used to conform the computer model and determine formation properties.

Abstract: A method and system for averting or mitigating undesirable drilling events during a drilling process is disclosed. The state of the drilling rig is detected, preferably automatically, based on surface and/or downhole measurement data. One or more undesirable drilling events are detected by correlating the acquired measurement data with the detected state. A drilling rig action is determined which averts or mitigates a detected undesirable drilling event. Finally, the drilling process is overridden by commanding performance of the action. The algorithm used in detecting the most likely rig state is preferably probabilistic in nature, and is even more preferably based on particle filtering techniques.

Abstract: An automated method and system for recognizing a well control event includes determining a state of drilling operations. When drilling operations are in a circulating state, a benchmark for a relative flow value. The relative flow value is based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore. A limit on variation of the relative flow value is determined from the benchmark. A cumulative sum for the relative flow value is determined over time in response to the relative flow value exceeding the limit. A well control event is recognized based on the cumulative sum.

Abstract: A rotary blowout preventer has a first and a second fluid circuit. Each of the fluid circuits are defined into and out of a stationary body and between the stationary body, a rotating body, and two seals. The first fluid circuit is physically independent from the second fluid circuit although they share a seal interface. A fluid is introduced into the first fluid circuit at a pressure responsive to the well bore pressure. A fluid is introduced into the second fluid circuit at a pressure responsive to and lower than the pressure of the fluid in the first circuit. Adjustable orifices are connected to the outlet of the first and second fluid circuits to control such pressures within the circuits. Such pressures affect the wear rates of the seals. The system can therefore control the wear rate of one seal relative to another seal. A thrust bearing is added to share the load placed upon the upper bearings. The thrust bearing is connected between the top end of a packer sleeve and the stationary body.

Abstract: Methods and apparatus for monitoring and controlling the pressure in a wellbore characterized by a drilling system utilizing real-time bottom hole pressure measurements and a control system adapted to control parameters such as well shut-in, drilling fluid weight, pumping rate, and choke actuation. In the preferred embodiments, the control system receives input from the bottom hole pressure sensor as well as pressure sensors, mud volume sensors, and flowmeters located at the surface. The control system then adjusts one or more of drilling fluid density, pumping rate, or choke actuation to detect, shut-in, and circulate out wellbore influxes. The preferred system operates automatically without any manual intervention in well control processes.

Abstract: A method is provided for gathering information on the pore pressure in an earth formation surrounding a wellbore. The method includes the initial steps of selecting at least one suitable property (e.g., porosity, drilling fluid composition, etc.) of the drilling environment (which is defined by the wellbore and the surrounding formation) and at least one NMR parameter (e.g., T2 distribution) in an NMR measurement response. The method selects a suitable property for which values over a plurality of wellbore depths can be correlated with the characteristics or behavior of the pore pressure in the earth formation. The method further includes conducting an NMR measurement at a plurality of wellbore depths, thereby generating an NMR response from the drilling environment. The measured values of the NMR parameter in the NMR response are then correlated with values of the suitable property.

Abstract: Methods and systems are disclosed for downhole processing of measurements made in a wellbore during the construction of the wellbore. The system includes a sensors located downhole adapted to measure a two downhole parameters. The system uses a downhole processor to calculate a statistical relationship, preferably covariance, between the two downhole parameters. A transmitter located downhole and in communication with the downhole processor is used to transmit the calculated statistical relationship to the surface. At the surface the statistical relationship is compared with surface acquired data and surface drilling operating parameters are altered based on the statistical relationship.

Abstract: A method and system for averting or mitigating undesirable drilling events during a drilling process is disclosed. The state of the drilling rig is detected, preferably automatically, based on surface and/or downhole measurement data. One or more undesirable drilling events are detected by correlating the acquired measurement data with the detected state. A drilling rig action is determined which averts or mitigates a detected undesirable drilling event. Finally, the drilling process is overridden by commanding performance of the action.

Abstract: Methods and systems are provided for varying fluid pressure in a circulation system while circulating a kick out of a well bore 30 drilled through a subterranean formation using a drilling rig 25 and a drill string 50. The kick may be automatically circulated out of the well bore and/or a kill fluid may be circulated into the well bore. A controller 100 reduces the circulation rate by automatically controlling the rate of the pump 90 and the position of well bore choke 70. Various sensors interconnected with the controller may be used to maintain circulation system operation. The controller may control various components utilized in the circulation procedure to maintain a substantially constant bottom hole pressure on the formation while circulating the kick out of the well.

Abstract: A method is disclosed for reducing noise in a measured telemetry signal. The method includes tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal band. The at least one harmonic has a frequency outside a telemetry signal band. The characteristic of the noise component is determined for at least one other harmonic thereof. The at least one other harmonic has a frequency inside the telemetry signal band. A noise reference is generated from the characteristic of the in band harmonic, and the noise reference is combined with the measured telemetry signal to generate a noise-canceled telemetry signal.

Abstract: A method is described for using an electro-rheological fluid as a drilling and completion fluid or as a well service or fracturing fluid. By adjusting the viscosity of the fluid through application of an electrical potential to the fluid, the fluid has enhanced flexibility and multiplicity of purpose over prior art fluids.

Abstract: The acoustic impedance of the drilling fluid may be found using reflections from a precise metal disk, and therefrom the density of the drilling fluid. Because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape, the first reflection from the metal disk may be used to calibrate the measurement. A method for determining a borehole fluid property is disclosed that includes (i) generating an acoustic signal within a borehole fluid, (ii) receiving reflections of the acoustic signal from the fluid, and (iii) analyzing a reverberation portion of the acoustic signal to determine the property. The analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property.

Abstract: A drill string is equipped with a down hole sub assembly which contains sensors to detect equipment condition during drilling. The sub assembly has no electrical communication with the drill bit itself, and the sensors detect drill bit condition from vibrations or strain or other detectable phenomena. Sensors in the bit itself are not needed.

Abstract: An automated method and system for recognizing a well control event includes determining a state of drilling operations. When drilling operations are in a circulating state, a benchmark for a relative flow value. The relative flow value is based on a flow of drilling fluid into a well bore and a flow of drilling fluid out of the well bore. A limit on variation of the relative flow value is determined from the benchmark. A cumulative sum for the relative flow value is determined over time in response to the relative flow value exceeding the limit. A well control event is recognized based on the cumulative sum.

Abstract: The pressure reading tool includes a housing with an interior chamber and an orifice extending from the chamber to the exterior of the housing. A pulse member with a magnetostrictive ring and an excitation source are disposed within the chamber to produce a highly agitated fluid discharge through the orifice. The magnetostrictive ring, chamber volume, and orifice cooperate to induce Helmholtz resonance frequencies in the fluid in the chamber to thereby enhance the agitation of the fluid discharge. A sheathing encapsulates the pulse member to protect it from contact with the fluid. A dampening element is also interposed between the pulse member and housing to isolate vibration.

Abstract: A method and apparatus for controlling the riser base pressure and detecting well control problems, such as kicks or lost circulation, during drilling of an offshore well using a gas-lifted riser. The pressure control apparatus preferably includes two separate control elements, one to adjust the pressure at the surface (prs) and the mass flow rate out of the top of the riser ({dot over (m)}o) to compensate for changes in riser base pressure (prb) and the other to adjust either or both of the boost mud flow rate (qb) and lift gas flow rate (qg) to maintain a constant or nearly constant mass flow rate entering the base of the riser ({dot over (m)}i). According to the method of the present invention, the well return flow rate (qw) is preferably determined by directly measuring various other parameters and then computing qw from the measured parameters. The computed value of qw may be compared to the drill string flow rate (qc) to detect well control problems, such as kicks or lost circulation.

Abstract: A new method for evaluating the efficiency of a sweep for removing cuttings from a borehole in a subterranean formation during a drilling operation. The method evaluates sweep efficiency on a “mass in” versus “mass out” basis. The method uses downhole density readings taken with a pressure-while-drilling tool inserted in the drill string. Measurements of hydrostatic pressure are converted into equivalent circulating density measurements which in turn are used in calculating the sweep efficiency. The method affords real time estimates at the wellsite of the quantity of formation cuttings brought out of a wellbore by a sweep.

Abstract: Determining the downhole rheological properties of a wellbore fluid. The method includes moving the wellbore fluid through a wellbore tool assembly into a wellbore at a first flow rate. A pressure is measured at a first position proximate a bottom of the wellbore. A pressure is measured at a second position in the wellbore axially separated from the first position. The wellbore fluid is then moved through the wellbore tool assembly at a second flow rate. Measuring pressure at the first and second positions is repeated, and at least one rheological property is determined from the pressure measurements.

Abstract: The invention relates to a method for use in sampling, flow measuring, quantity gauging, or possibly other analysis performed in reservoir fluid found in a ground formation. An object of the invention is to perform the sampling, flow measuring and quantity gauging or the remaining analyses in situ on stabilized reservoir fluid that contains a negligible amount drill fluid. Analysis is possible by sealing off an area of the well at the hydrocarbon carrying layer and passing a volume of reservoir fluid into a drill string for analysis by accessories located in the drill string. After the analyses are performed, the reservoir fluid is returned to the hydrocarbon carrying layer.

Abstract: A carrier apparatus for connection with a pipe string for use in transporting at least one gauge downhole through a borehole. The apparatus includes a tubular body for connection with the pipe string having a bore for conducting a fluid therethrough and an outer surface, wherein the outer surface has at least one longitudinal recess formed therein. Further, at least one insert defining an internal chamber for receiving a gauge is mounted with the body such that at least a portion of the insert is receivable within the recess for engagement therewith. The apparatus also includes an interlocking interface comprised of the engagement between the insert and the recess, wherein the interlocking interface is configured such that the insert inhibits radial expansion of the body adjacent the recess. Finally, at least one passage provides fluid communication between the gauge and one of the bore of the body and the borehole.

Abstract: A system of measuring properties, such as pressure, and transmitting measurements in a subterranean well. In a described example, a valve system includes a valve having a closure member. A sensor senses a pressure differential across the closure member. A tool positioned in the valve transmits power to the valve to operate the sensor, and the sensed pressure differential is transmitted from the valve to the tool.

Abstract: An apparatus and method is provided for substantially continuously drilling and disposing of drill cuttings and dust to minimize airborne contamination while providing protection against overload using enhanced computer control. A drill stem with a bit is used to form the drill hole. A flushing mechanism utilizes vacuum or pressurized water to create a bailing fluid flow for flushing the cuttings and dust from the drill hole for disposal. A transducer monitors at least one first parameter of the bailing fluid flow, and a sensor may also monitor at least one second parameter of a flow of a driving fluid under pressure for feeding the drill stem and bit into the earth. A controller is utilized to regulate the rate of feed and/or driving of the stem and bit dependent on the levels of the parameters being monitored.

Abstract: An apparatus is used with a drilling assembly for drilling a borehole. The drilling assembly has an impact device linked to a drill head. The impact device is powered by a first fluid under a first pressure to impart a percussive force to the drill head. The percussive force is a function of the first pressure. A thruster of the drilling assembly is also linked to the drill head. The thruster is powered by a second fluid under a second pressure to impart a thrust force to the drill head. The thrust force is a function of the second pressure. Additionally, a rotator of the drilling assembly is linked to the drill head. The rotator is powered by a third fluid under a third pressure to impart a torque to the drill head. The torque is a function of the third pressure. The apparatus includes a first pressure sensor communicating with the first fluid to output a first electrical signal that is a function of the first pressure.

Abstract: An anti-plugging oscillating shear valve system for generating pressure fluctuations in a flowing drilling fluid comprising a stationary stator and an oscillating rotor, both with axial flow passages. The rotor oscillates in close proximity to the stator, at least partially blocking the flow through the stator and generating oscillating pressure pulses. The rotor passes through two zero speed positions during each cycle, facilitating rapid changes in signal phase, frequency, and/or amplitude facilitating enhanced data encoding. The rotor is driven by a electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. In one embodiment, a torsional spring is attached to the motor and the resulting spring mass system is designed to be near resonance at the desired pulse frequency. The torsion spring may be a solid torsion bar or a magnetic spring.

Abstract: Methods and systems are provided for varying fluid pressure in a circulation system while circulating a kick out of a well bore 30 drilled through a subterranean formation using a drilling rig 25 and a drill string 50. The kick may be automatically circulated out of the well bore and/or a kill fluid may be circulated into the well bore. A controller 100 reduces the circulation rate by automatically controlling the rate of the pump 90 and the position of well bore choke 70. Various sensors interconnected with the controller may be used to maintain circulation system operation. The controller may control various components utilized in the circulation procedure to maintain a substantially constant bottom hole pressure on the formation while circulating the kick out of the well.

Abstract: The pressure reading tool includes a housing with an interior chamber and an orifice extending from the chamber to the exterior of the housing. A pulse member with a magnetostrictive ring and an excitation source are disposed within the chamber to produce a highly agitated fluid discharge through the orifice. The magnetostrictive ring, chamber volume, and orifice cooperate to induce Helmholtz resonance frequencies in the fluid in the chamber to thereby enhance the agitation of the fluid discharge. A sheathing encapsulates the pulse member to protect it from contact with the fluid. A dampening element is also interposed between the pulse member and housing to isolate vibration.