Abstract: A fluid circulation apparatus for interconnection with a wellbore tubing string for particular use in drilling deviated wellbores, such as with coiled tubing. The circulation apparatus has a tubular body member with a longitudinal bore extending eccentrically therethrough and threads for interconnection with a tubing string. A fluid communication port extends through a sidewall of the tubular body member, and a shiftable sleeve is placed thereacross for selectively permitting and preventing fluid flow through the fluid communication port. The valve is biased in a normally closed position by way of a spring and/or hydraulic fluid. Fluid control means, such as a hydraulic fluid source conveyed from a downhole Hydraulic Power Unit to an internal piston, opens or closes the valve in response to electrical signals sent to the Hydraulic Power Unit from the earth's surface.

Abstract: A subterranean drill bit operable with a rotational drive source is provided for drilling in subterranean earthen materials to create a borehole having a borehole wall. The drill bit comprises a drill bit body having a base portion, a gauge portion and a face portion disposed about a bit axis. A plurality of diamond cutting elements are fixedly disposed on and project from the face portion and are spaced from one another. The cutting elements are disposed for causing a net radial imbalance force during the drilling along a net radial imbalance force vector substantially perpendicular to the bit axis. A substantially continuous cutter devoid region is disposed on the gauge portion about the force point, and a bearing support is disposed in the cutter devoid region about the force point for substantially continuously contacting the borehole wall during the drilling.

Abstract: A subterranean drill bit is provided that comprises a drill bit body having a base portion disposed about a longitudinal bit axis, a gauge portion disposed about the bit axis and extending from the base portion, and a face portion disposed about the bit axis extending from the gauge portion. The drill bit further includes a plurality of cutting elements fixedly disposed on and projecting from the face portion and spaced from one another. A hydrostatic bearing is disposed in the gauge portion to create a hydrostatically lubricated low friction zone that facilitates rotation of the drill bit without gripping of rotation of the drill bit is thereby maintained substantially at one location on the drill bit, which avoids backwards whirling and provides stable bit rotation.

Abstract: Apparatus for drilling a large diameter hole in the surface of a material includes an upper body; a lower body rotatably connected to the upper body; a motor for rotating the lower body relative to the upper body; cutting discs, connected to the lower body for cutting the material and moving the material toward a casing; the casing, extending through the upper and lower bodies, for receiving the cuttings from the cutting disk and carrying the cuttings through the bodies; and an engagement assembly for limiting downward travel of the casing and the bodies so that the casing is securable in a preselected position of downward travel and is removable through the upper side of the upper body. The engagement assembly engages the casing with the lower body so that the casing is rotated with the lower body. An auger having a hollow interior can be provided at the lower end of the casing.

Abstract: A method of producing methane by injecting inert gas, such as nitrogen, through an injection well into a solid carbonaceous subterranean formation (e.g., coal) and recovering methane from a production well(s). Methane desorption is achieved by reduction in methane partial pressure rather than by reduction in total pressure alone.

Abstract: A method of increasing the rate of methane production from a coal seam includes introducing a desired volume of a gas, that causes coal to swell, into the coal seam adjacent a wellbore, maintaining the coal seam adjacent the wellbore in a pressurized condition for a period of time to permit the gas to contact a desired area of the coal adjacent the wellbore, and relieving the pressure within the coal seam by permitting fluids to flow out from the wellbore at a rate essentially equivalent to the maximum rate permitted by the wellbore and any surface wellbore flow control equipment. Uneven stress fractures should be created in the coal by this method which will increase the near wellbore permeability of the coal seam.

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: A method of exploring for hydrocarbons is disclosed wherein core is obtained over substantially the entire length of a well and substantially all lithologies represented within the core are analyzed at a core analysis facility located adjacent the well. A measurement of a plurality of physical properties of the core are made promptly after the core is removed from the well. Thereafter, from the measurement of these physical properties, a depth correlated record is generated, and is used (a) to adjust the drilling plan for that well while it is being drilled, (b) used as inputs into other exploration processes, such as seismic surveys, magnetic surveys and gravity surveys, or (c) used for correlation with other depth correlated records obtained from other wells.

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 of acquiring seismic data is disclosed which includes a horizontal towed receiver array in conjunction with at least one vertically oriented receiver array formed from a plurality of receiver elements spaced apart vertically within a plurality of cable. By simultaneously recording the data from both arrays, seismic data can be acquired for locations directly beneath a fixed obstruction, which a towing vessel has had to steer around.

Abstract: A hydrocyclone separator for separating oil from water includes a substantially cylindrical first portion with a central overflow outlet and at least one tangential flow inlet, an essentially single angled conical second portion, and a substantially cylindrical third portion, with a central underflow outlet. The hydrocyclone separator is made in accordance with the following relationships:do<du<Dc0.1.ltoreq. di/Dc.ltoreq. 0.40.01.ltoreq. do/Dc.ltoreq. 0.060.ltoreq. Lc/Dc.congruent. 2.03.degree..ltoreq..alpha..ltoreq. 30.degree.0.1.ltoreq. du/Dc.ltoreq. 0.59.ltoreq. Ls/Dc.

Abstract: A source array useful in vertical seismic profiling is disclosed wherein a first set of source elements having horizontal extent is spaced to have at least a first direction and a second direction, and a second set of source elements having vertical extent are spaced below the first set of source elements. The source elements in the source array are sequentially activated to focus the seismic energy along selected radial paths through the earth's subsurface.

Abstract: Apparatus and method for orienting a collar on a fluid conducting conduit, such as a drill string, includes an orifice through the wall of the conduit and a latch assembly for latching the collar to the conduit. The latch assembly allows fluid communication through the orifice and rotates the collar when the conduit is rotated in a first direction about the longitudinal axis of the conduit. The latch assembly unlatches the collar from the conduit, prevents fluid communication through the orifice, and allows the conduit to rotate relative to the collar when the conduit is rotated ion a second, opposite direction.

Abstract: A system is disclosed for preventing oil droplet size reduction when introducing an oil/water stream into an oil-from-water separation unit. The system includes a conduit extending from a source of the oil/water stream to an inlet of the oil-from-water separation unit, which can be one or more hydrocyclone separators, centrifuges, settling tanks and the like. A throttling device is operatively connected to the conduit for regulating the quantity of the oil/water stream passing therethrough. The throttling device eliminates the shearing of the fluid, thereby preventing oil droplet size reduction. The throttling device can include a progressive cavity motor with a rotation control mechanism connected to the rotor of the motor to control the rpm of the rotor, and thus the quantity and pressure of the fluid passing therethrough.

Abstract: A solids flow distribution apparatus is disclosed for use with two or more solid separation devices, such as shale shakers. The appartatus includes a plenum in communication with a source of flow of solids and liquid, such as from a drilling rig's mud system. The plenum includes lower outlets positioned adjacent inlet zones for each solid separation device. Valves are positioned across the lower outlets for regulating the quantity of solids and liquids that flow into the inlet zones of each solid separation device. A variable distribution apparatus is included within the plenum adjacent the flow inlet for regulating the proportion of solids directed towards each solid separation device.

Abstract: A whirl resistant drill bit is disclosed for use in rotary drilling. The drill bit includes a generally cylindrical bit body with a plurality of cutting elements extending out from a lower end surface. The cutter elements are grouped in sets such that a first set of cutters are disposed at substantially an equal radius from a center of the bit body to create a groove in the material being drilled. A second set of cutters is connected to the lower end surface with each cutter therein in overlapping radial relationship with each other and extending a maximum distance from the lower end surface less than that of the first set of cutters. At least one cutter of the second set is in overlapping radial relationship with at least one of the cutters within the first set of cutters. This cutter arrangement causes the drill bit to cut grooves within the formation material that tends to prevent destructive bit whirl. Further, adjustments can be made to vary the back rake angle and side rake angle to prevent bit whirl.

Abstract: A hydrocyclone separation system is disclosed for separating a fluid mixture into at least two separate density components and for precluding remixing of semi-separated higher density components. A first and second hydrocyclone separators each has a central overflow outlet, a tangential fluid inlet, and a central overflow outlet. The first and second hydrocyclone separators are oppositely disposed such that a curved flow direction conduit extends from the underflow outlet of the first hydrocyclone separator to the tangential fluid inlet of the second hydrocyclone separator. Thereby, rotating fluid exiting the underflow of the first hydrocyclone separator is tangentially passed into the inlet of the second hydrocyclone separator precluding remixing of semi-separated higher density components and increasing the overall separation efficiency of the system.

Abstract: A method of flowing a high viscosity substance, such as a delayed cross-linked fracturing gel, through a conduit or well fracture at a low apparent viscosity comprises selecting a cross-linkable fluid having nonhomogeneous flow properties and flowing the fluid through the conduit or well fracture at fluid conditions which produce nonhomogeneous flow of the fluid at low apparent viscosity, and preferably at a minimal apparent viscosity. Also included is a method of determining the fluid conditions at which the fluid flows nonhomogeneously at a low or minimal apparent viscosity. The method may further comprise crosslinking the fluid while inputting shear energy to the fluid and determining the ranges of shear energy input to the fluid which produce nonhomogeneous flow of the fluid at a low apparent viscosity. The fluid may then be flowed at flow rates which create fluid shear energies within the ranges which produce nonhomogeneous flow at a low or minimal apparent viscosity in a conduit or well fracture.

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: Disclosed is a method for disconnecting a marine riser assembly from a subsea wellhead when the marine riser assembly contains substantially gas, the marine riser assembly comprising a riser and a wellhead connector having an internal shoulder for abutting against the top of the subsea wellhead. The method comprises equalizing the pressure acting on the internal shoulder of the wellhead connector and the seawater pressure acting external to the wellhead connector.