Abstract: A well monitoring system particularly useful in detecting kicks in the well includes a well, a well system, and a computing apparatus. The well defines a wellbore and the well system includes at least one sensor measuring at least one well condition. The computing apparatus hosts a well monitoring software component that performs a method to detect a kick in a well. The method includes: storing a set of real-time data from a measurement of a well condition by the sensor, the measurements being correlative to an unplanned fluid influx into the well; modeling the operation of the well with a physics-based, state space model of the well system to obtain an estimate of the well condition; and applying the real-time data set and the estimate to a probabilistic estimator to yield a probability of an occurrence of a kick and a confidence measure for the probability.

Abstract: A well monitoring system particularly useful in detecting kicks in the well includes a well, a well system, and a computing apparatus. The well defines a wellbore and the well system includes at least one sensor measuring at least one well condition. The computing apparatus hosts a well monitoring software component that performs a method to detect a kick in a well. The method includes: storing a set of real-time data from a measurement of a well condition by the sensor, the measurements being correlative to an unplanned fluid influx into the well; modeling the operation of the well with a physics-based, state space model of the well system to obtain an estimate of the well condition; and applying the real-time data set and the estimate to a probabilistic estimator to yield a probability of an occurrence of a kick and a confidence measure for the probability.

Abstract: Methods of jarring include communicating between a surface command device and jars in a drill string, the drill string composed of spaced apart jars positioned in a corresponding plurality of wired and/or wireless pipe sections. The methods include selectively controlling charging, firing, amount of force, and/or direction of force of the jars using digitally-controlled surface command devices. One method includes firing a sub-set or all of the jars in a controlled manner and determining depth of a stuck drill string section through analysis of behavior or performance of the fired jars. Other methods include subsequently firing one or more of the jars again below the stuck drill string section. Other methods include selectively firing, using digital signals from the surface command device, jars sequenced in time so that their forces meet in a constructive or destructive manner at a preselected point in the drill string.

Abstract: A method and apparatus for testing a blowout preventer (BOP) wherein a pressurization unit applies fluid to an isolated portion of the throughbore of the BOP. A signal that is representative of the actual pressure in the isolated portion of the throughbore over successive time points and a pre-determined non-deterministic finite state automaton are used to predict the pressure in the isolated portion of the throughbore as a function of time relative to a pre-determined acceptable leak rate and the time at which stability is achieved. In one embodiment stability is achieved when successive predicted pressures are within a predetermined difference over a predetermined interval of time. Visual indications are provided to depict the progress of testing.

Abstract: A method and apparatus for testing a blowout preventer (BOP) wherein a pressurization unit applies fluid to an isolated portion of the throughbore of the BOP. A signal that is representative of the actual pressure in the isolated portion of the throughbore over successive time points and a pre-determined non-deterministic finite state automaton are used to predict the pressure in the isolated portion of the throughbore as a function of time relative to a pre-determined acceptable leak rate and the time at which stability is achieved. In one embodiment stability is achieved when successive predicted pressures are within a predetermined difference over a predetermined interval of time. Visual indications are provided to depict the progress of testing.

Abstract: A method and apparatus for remotely generating pressure signals in a fluid stream for telemetry purposes with minimal insertion loss and susceptibility to blocking flow of the fluid stream by providing a straight through acceleration path for the fluid stream followed by a straight through diffusion path, wherein pressure pulses representing data are generated by turbulence resulting from periodic disturbances made in the diffusion path.

Abstract: Conventional drill pipe is rotated at a rate sufficient for distributing deforming forces substantially uniformly around the circumference of the drill pipe at each location along the length of the drill pipe disposed within the curved portion while the pipe is passed through the curved portion of a short-radius wellbore. The drill pipe arrives in the lateral portion in operable condition for drilling to extend the lateral portion and is retrieved from the wellbore in reusable condition.

Abstract: Rotational orientation of a drillstring is monitored a plurality of times during each rotation of a drillstring for monitoring the rotational orientation of a curve drilling assembly on a drillstring. A defined rotational orientation of a downhole location on the drillstring with respect to the curve drilling assembly is established. At least one reference signal generator having a known relationship to the down hole location on the drillstring and that rotates with the drillstring is provided at the surface. A reference signal is generated each time a reference signal generator rotates past a detector. A pressure signal is generated each time the drillstring rotates through the defined rotational orientation with respect to the drill bit steering device. Occurrences of the plurality of surface reference signals and the pressure signal are timed and compared for monitoring the rotational orientation of the drill bit steering device.

Abstract: A curve drilling assembly operable with a rotary drill string is provided for drilling a curved subterranean borehole. The assembly includes a curve guide, a rotary drill bit, an imbalance force assembly, and a bearing assembly. The curve guide is connectable with the drill string for deflecting the drill string toward the outside radius of the curved borehole. The imbalance force assembly, which preferably is provided by selectably disposing cutting elements on the drill bit, is rotatable with the drill string for creating a net imbalance force along a net imbalance force vector substantially perpendicular to the longitudinal axis of the drill bit during drilling. The bearing assembly is rotatable with the drill string and is located in the curve drilling assembly near the cutting elements of the drill bit for intersecting a force plane formed by the longitudinal bit axis and the net imbalance force vector and for substantially continuously contacting the borehole wall during drilling.

Abstract: Apparatus and method for positioning a tool, such as a surveying instrument, in the deviated section of a borehole includes a flexible rod and a positioning assembly. The flexible rod extends from the vertical section into the deviated section of the borehole with the tool being connected to the downhole end of the rod. The positioning assembly is connected to the uphole end of the rod for positioning the downhole end of the rod in the deviated section of the borehole when the positioning assembly and the uphole end of the rod are in the vertical section of the borehole. In one embodiment, the positioning assembly is a biasing assembly, such as a weight, for urging the downhole end of the rod and tool into the deviated section. In another embodiment, the positioning assembly is an orienting assembly for rotationally orienting the rod and tool in the borehole as the rod is lowered into the borehole.

Abstract: A method of determining the rotational orientation of a downhole tool on a rotatable conduit, such as a collar on a drillstring in a borehole, without interrupting the rotation of the drillstring, includes establishing the initial rotational orientation of the downhole tool; creating a pressure change to generate a signal; providing a reference point on the conduit; generating a reference signal each time the reference point rotates past a detector; generating the signal each time the conduit rotates through the defined rotational orientation with respect to the tool; and timing and comparing the occurrences of the referenced signal and the signal in order to monitor the rotational orientation of the downhole tool.

Abstract: Apparatus and method for deflecting the drilling direction of a rotary drill string and drill bit through a borehole wall include an anchor, a housing, and a chute. The anchor anchors the apparatus in the borehole. The housing is connectable to the anchor and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the housing. The passageway has an entrance through the uphole end of the housing and an exit through the sidewall of the housing. The chute is slidably disposed in the housing passageway and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the chute from the uphole end through the downhole end. The chute passageway passes the drill bit and drill string through the chute.

Abstract: Apparatus for stabiliing a rotary drill string and drill bit used to drill a borehole in a material, such as a subterranean formation, includes an imbalanced drill collar and a drill bit connected to the drill collar. The imbalanced drill collar creates a drill string imbalance force directed radially outwardly from the center of rotation of the drill collar through a predetermined area on the circumference of the drill collar and urges the predetermined area into contact with the borehole wall as the drill string rotates. The drill bit includes a drilling surface for contacting the material and drilling the borehole in the material, the drilling surface including a cutting zone for cutting the borehole in the material and the bearing zone having a low coefficient of friction relative to the cutting zone.

Abstract: A method is disclosed for determining rock compressive strength of a subterranean formation penetrated by a wellbore. A mathematical model of a drill bit and an estimate of rock ductility of a particular subterranean formation in conjunction with weight-on-bit (WOB), bit rotational speed RPM, and rate of penetration (ROP) are used as inputs. From the above inputs, the rock compressive strength can be determined while the wellbore is being drilled or afterwards. A depth correlated log can be generated of rock compressive strength that can be compared to other logs obtained from adjacent wellbores to obtain a refined estimate of the depth of a particular subterranean formation feature. Further, the above method can be utilized for obtaining an indication of bit wear or bit damage while the bit is drilling a wellbore by comparing a first rock compressive strength log of a wellbore to a rock compressive strength log being generated while the drill bit is actually drilling a second wellbore.

Abstract: To divert sufficient fluid flow through an unsealed bearing section of a downhole drilling motor, a flow control apparatus is provided for insertion between the power section of the motor and the bottom of a drill bit which is to be turned by the motor. The flow control apparatus includes a variable flow channel having a selectable effective cross-sectional area preferably embodied by a valve. A selected effective cross-sectional area is chosen by a control mechanism, such as a snap ring or a spring used to control the position of a valve member of the valve in response to different flow rates of fluid pumped through the valve depending upon whether the drill bit is on-bottom or off-bottom. In one embodiment the apparatus is incorporated within the interior of a drill bit which has angled flow channels to direct flushing fluid flow to side wall locations where reaming occurs. Flow through these outlets is controlled by positioning of the valve member.

Abstract: The orientation of a downhole steering assembly used in drilling a horizontal well is located with respect to the earth using a sub placed above the downhole assembly. The sub comprises a housing having a central bore defining an inlet flow passageway said housing further defining a toroidal chamber in communication with said passageway. The toroidal chamber has a pocket, a valve seat, and a spherical valve that is rotatable in said toroidal chamber from a normally seated position in the pocket. Upon rotation of the drill string the spherical valve plugs the valve seat and causes an increase in the resistance to flow in the drilling mud through the drill string that can be detected at the surface.

Abstract: To stabilize a drill string and to reduce or prevent wellbore deviation in directional drilling, weight rods by which weight is to be applied to drill bit are maintained free-standing and under compression within a drill string while the drill string itself is maintained in tension to limit or prevent lateral deviation of the weight rods in compression. Weight provided by the weight rods is transferred to the drill bit through a load transfer member in compression connected between the drill string and the drill bit.

Abstract: An excavating system, such as for drilling an oil or gas well, includes a source of high pressure fluid and a drillstring through which the fluid is conducted to an excavating apparatus connected to the bottom of the drillstring. The excavating apparatus includes a drill bit having mechanical cutting elements for mechanically boring into an earthen formation. The excavating apparatus also includes a nozzle rotatably mounted to the body of the drill bit so that the nozzle is rotatable about an axis of rotation different from the axis of rotation of the drill bit. As the drill bit is rotated about its axis of rotation, high pressure fluid is ejected from the nozzle to rotate the nozzle about its axis of rotation while the nozzle orbits the axis of rotation of the drill bit.

Abstract: A downhole drilling apparatus for use with an undergauge drill bit comprises a downhole drilling motor which includes a housing and means for rotating the drill bit relative to the housing about an axis of rotation. The apparatus also comprises stabilizers connected to the housing for stabilizing the drill bit, and it further comprises cutters connected to the housing for cutting a borehole wall created by passage of the drill bit, wherein the cutters extend radially outwardly relative to the axis of rotation to a greater extent than does the drill bit. A drilling assembly including such a drilling apparatus and a method of drilling a substantially vertical borehole in an earthen formation utilizing such an apparatus are also disclosed.

Abstract: A system for directional drilling and related method of use is described herein which utilizes a drillstring suspended within a wellbore with an MWD and downhole turbine or motor connected adjacent a drill bit on a lower end of the drillstring, and with a top drive and/or rotary table connected adjacent an upper end of the drillstring. Within the method, desired limits of drilling associated parameters are inputted into a memory associated with a programmable digital computer. While drilling the wellbore, transmitted values of the drilling associated parameters are inputted into the memory. If the transmitted values are outsude of the desired limits, necessary adjustments are calculated and then made to weight-on-bit (WOB), RPM and/or drillstring azimuthal orientation to bring the transmitted values within the desired limits.