Abstract: An example system is executable by one or more processors to retrieve a development model and a production model; translate the development model and the production model into formal specifications; generate a set of theorems for checking constrained equivalence between the development model and the production model; combine formal specification of the development model, formal specification of the production model, and the set of theorems into a combined specification; and prove the constrained equivalence based on the theorems.

Abstract: Disclosed herein is a system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system can include a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action can be varied by periodically varying the rotation speed and/or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, results in borehole deviation. Action of the drill bit can be varied independently of the rotation rate of the drill string.

Abstract: Apparatus and methods for removing the effects of directional drilling systems drilling fluid pulses to allow a MWD mud pulse telemetry system to operate without interference. The methodology is based upon Synchronous Time Averaging (STA). With STA, any pressure fluctuation that is cyclical (or synchronous) with a measurable event can be profiled and subsequently subtracted from a mud pulse telemetry signal. STA functions by placing a strobe in such a manner that the strobe is triggered for each cyclical event. The cyclical event in this disclosure is one (or more) revolution(s) of the drill string. If there is a pressure fluctuation that correlates to that cyclical event, it will be identified by a stable profile of that pressure fluctuation. This pressure profile is then used to remove the cyclical pressure fluctuation from the input mud pulse telemetry signal thereby allowing normal operation of the mud pulse telemetry system.

Abstract: Disclosed herein is a system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system can include a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action can be varied by periodically varying the rotation speed and/or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, results in borehole deviation. Action of the drill bit can be varied independently of the rotation rate of the drill string.

Abstract: Disclosed herein is a system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system can include a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action can be varied by periodically varying the rotation speed and/or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, results in borehole deviation. Action of the drill bit can be varied independently of the rotation rate of the drill string.

Abstract: A drilling system utilizing a plurality of independent telemetry systems. The drilling system uses a drill collar as a pressure housing for downhole components of the system. One or more sensors are disposed within the pressure housing. These sensors can be MWD sensors, LWD sensors, or both MWD and LWD sensors. A plurality of independent borehole telemetry systems is used to telemeter sensor response data to the surface of the earth. Each sensor cooperates with a downhole component of at least one of the independent telemetry systems. The plurality of telemetry systems can be of the same type, such as a mud pulse systems. Alternately, the telemetry systems can be of different types including a mud pulse system and an electromagnetic system.

Abstract: A system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system comprises a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action is varied by periodic varying the rotation speed or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, resulting in borehole deviation.

Abstract: An electromagnetic well borehole telemetry system for transmitting information between a downhole transceiver, disposed preferably within a borehole assembly in the borehole, and a surface transceiver positioned at or near the surface of the earth. A trigger and cooperating strobe are used to define strobe increments. Synchronous telemetry measurements made during the strobe increments are algebraically summed to identify a synchronous cyclical noise component in a composite electromagnetic telemetry signal. Any non cyclical noise components occurring during the strobe increments algebraically cancel in the algebraic summing operation. The cyclical noise component is then removed from the composite signal thereby increasing the signal to noise ratio of the telemetry system. The system is particularly effective in minimizing electromagnetic noise generated by the rotation of a rotating element such as the rotary table or top drive of a drilling rig.

Abstract: Method and apparatus for optimizing mud pulse telemetry data rate by processing a sequence of measured pulses to minimize adverse effects of pressure pulse reflections, attenuations and distortions. A downhole telemetry unit cooperating with a sensor and disposed in a MWD or LWD logging tool generates a sequence of pulse within the mud column. The sequence is encoder to represent the response of the sensor disposed within the logging tool. The encoded pulse sequence is sensed at the surface of the earth using a pressure transducer. The output of the transducer yields an electrical signal that is typically attenuated and can contain reflections and distortions. This measured signal output is processed to minimize the effects of pulse reflections, attenuations and distortions thereby yielding a primary pulse sequence that is more representative of the response of the sensor and allowing an increase in mud pulse telemetry data rate.

Abstract: A drilling system utilizing a plurality of independent telemetry systems. The drilling system uses a drill collar as a pressure housing for downhole components of the system. One or more sensors are disposed within the pressure housing. These sensors can be MWD sensors, LWD sensors, or both MWD and LWD sensors. A plurality of independent borehole telemetry systems is used to telemeter sensor response data to the surface of the earth. Each sensor cooperates with a downhole component of at least one of the independent telemetry systems. The plurality of telemetry systems can be of the same type, such as a mud pulse systems. Alternately, the telemetry systems can be of different types including a mud pulse system and an electromagnetic system.

Abstract: An electromagnetic well borehole telemetry system for transmitting information between a downhole transceiver, disposed preferably within a borehole assembly in the borehole, and a surface transceiver positioned at or near the surface of the earth. A trigger and cooperating strobe are used to define strobe increments. Synchronous telemetry measurements made during the strobe increments are algebraically summed to identify a synchronous cyclical noise component in a composite electromagnetic telemetry signal. Any non cyclical noise components occurring during the strobe increments algebraically cancel in the algebraic summing operation. The cyclical noise component is then removed from the composite signal thereby increasing the signal to noise ratio of the telemetry system. The system is particularly effective in minimizing electromagnetic noise generated by the rotation of a rotating element such as the rotary table or top drive of a drilling rig.

Abstract: A typical dynamic bearing design comprises a ring shaped or circular thrust plate mounted at or near the end of a shaft, the shaft defining together with a surrounding sleeve a journal bearing by providing grooves on only one of the two surfaces facing the gap between the shaft and sleeve. On the ring shaped thrust plate supported by the shaft, the traditional upward thrust bearing defined between the lower face of the thrust plate and the facing surface of the sleeve is maintained; but no grooves are on the surface of the thrust plate distant from the shaft and a facing counterplate surface. Further, the journal bearing is defined to have an asymmetry so that a bias force pressure along the surface of the shaft toward the thrust plate is established.

Abstract: An electrostatic discharge apparatus for use with a hub and spindle assembly for a disc drive storage system comprising a spindle; a hub rotatably mounted on the spindle; a capsule formed at least in part from an electrically conductive material that can be placed in electrical communication with the hub and defining a chamber configured to hold an electrically conductive fluid and defining at least one capillary channel in fluid communication with an opening formed in the capsule, the opening configured to permit rotation about the spindle, and to permit a meniscus formed by the conductive fluid proximate to the opening to electrically contact the spindle during rotation of the hub about the spindle.

Abstract: A system and method enables a file server, to support multi path input/output operations for Fibre Channel devices. Upon each Fibre Channel Arbitrated Loop initialization event generated, the system and method updates a path and device instance to track multiple paths to a given device. While the file server is attempting input/output operations, the failure of a given path can be corrected by the use of another path associated with a given device. The data structures generated by the low levels of the storage operating system are exposed for use by upper level services for routing a storage device identification purposes.

Abstract: The present invention provides a motor assembly for mounting to a base. The motor assembly includes a stator assembly having a plurality of stator teeth. Each stator tooth is configured to support a stator coil. The motor assembly also includes a flexible printed circuit having top and bottom surfaces and an end portion. The end portion is affixed to the stator assembly at the top surface. The bottom surface is affixed to the base.

Abstract: According to one example, a motor including a fluid dynamic bearing system is provided. The motor includes a first stationary member and a second member disposed for relative rotation and a fluid dynamic bearing region disposed therebetween. A stator is disposed with the first member and includes a plurality of stator teeth having a coil of wire wound thereon. A heat transfer device is further included, wherein the heat transfer device transfers heat away from the stator coils toward the bearing region. The transfer of heat may raise the temperature of the bearing fluid, thereby reducing bearing fluid viscosity. The heat transfer device may include one or more air vanes to direct air through, over, or adjacent the stator and/or thermally conductive materials or elements, and may further be incorporated into a flux shield.

Abstract: A fluid dynamic bearing motor features a stationary assembly, a rotating assembly supported on the stationary assembly, a fluid dynamic bearing system in a gap between the stationary and rotating assemblies, a radial capillary seal defined proximate a first end of the journal gap, and at least one re-circulation hole extending from the radial capillary seal to a second end of the journal gap. A single thrust shaft end bearing which pressurizes the shaft end to create an axial thrust bearing and drive bubbles in the fluid (where the fluid is a liquid) to the outer diameter of the shaft and into the recirculation path. The journal may be supported for rotation by dual sets of grooves; the dual groove asymmetry in the journal maintains a positive pressure between the journals.

Abstract: For a motor having fluid dynamic bearing(s) defined by surfaces of relatively rotatable motor members, aspects include providing a capillary reservoir between relatively irrotatable surfaces. The capillary reservoir may comprise a tapering gap that is vented to a gaseous environment through one end of the gap and is in fluidic communication with the fluid dynamic bearing(s) through another end of the gap. The gap may be axial, and the capillary reservoir may be disposed coaxially with one or more of the fluid dynamic bearing(s) about an axis of rotation. The capillary reservoir may extend from proximate a top portion of the motor to proximate a bottom portion of the motor.

Abstract: Motors having a magnetic force attenuator are described. In some embodiments, the motors comprise a stationary member having a base and a stator, a rotating assembly having a magnet and a magnetic force attenuator to attenuate the magnetic attraction force between the magnet and the base; and a fluid bearing to support rotation of the rotating assembly relative to the stationary member. The magnetic force attenuator typically comprises a material of high magnetic permeability, and modulates the magnetic attraction force between the magnet and the base of the motor.

Abstract: For a motor having liquid lubricated bearing surface(s), aspects include providing a column shaped Capillary Seal (CS) for storing and supply lubricating liquid to the bearing surface(s). The column shaped CS may have a cross-section substantially topologically equivalent to a circle. Aspects include disposing the column shaped CS between relatively rotational motor members or between relatively irrotational motor members. Other aspects include disposition of the column shaped CS in a spiral shape where one opening of the CS fluidicly communicates with the bearing surface and another opening vents to a gas environment. Still other aspects include disposing the column shaped CS circumferentially on surfaces of generally cylindrical shaped motor members. Such surfaces may oppose a second surface that is one of relatively rotational and relatively irrotational vis the surface. The column shaped CS may circumscribe an axis of a rotating member or may be disposed parallel to the axis of the rotating member.