Abstract: A downhole tool (10) for selectively circulating fluid in a borehole is disclosed. The tool operates via the use of a combination of deformable drop balls (36) and smaller hard drop balls (40). In use a deformable drop ball (36) moves a sleeve (20) exposing a radial port (30,32) to provide fluid circulation radially from the tool. The smaller drop ball (40) can then obstruct the radial port (32,30) and by the increased pressure the deformable drop ball (36) is extruded through the tool. The resulting pressure differential as the drop ball (36) moves causes the sleeve (20) to rise, releasing the smaller drop (40) ball and closing the radial port (32,30). The process can be repeated to selectively circulate fluid through the tool.

Abstract: The present invention provides apparatus and methods for expanding tubulars in a wellbore. In one aspect, a process of sealing an annular area in a wellbore is provided in which a tubular having perforations at a predetermined location and a sleeve concentrically covering substantially all of the perforations is expanded into substantial contact with an inner diameter of a tubular, such as a casing or a liner. In another aspect, a process of sealing an annular area in a wellbore is provided in which a tubular having perforation at a predetermined location and a sleeve concentrically coving substantially all of the perforations is expanded into substantial contact with a junction between two tubulars, such as a liner and a casing, or between two liners.

Abstract: A damping apparatus and method for a drillstring comprising a bit comprising providing to the drillstring a damping mechanism comprising magnetorheological fluid and generating an electromagnetic field affecting the magnetorheological fluid in response to changing ambient conditions encountered by the bit.

Abstract: The present invention relates to fluid systems comprising a first fluid comprising carbon dioxide and a second fluid comprising an alkaline crosslinked fluid. The fluid combinations of the present invention may be used, for example, in hydraulic fracturing, frac-packing, and gravel packing. Some embodiments of the present invention provide systems for treating a subterranean formation comprising a first fluid comprising a foamed carbon dioxide fluid, an emulsion of carbon dioxide, or a carbon dioxide gel; and, a second fluid comprising an alkaline crosslinked fluid.

Abstract: A method of propagating a fracture farther from a well-bore into an oil and/or gas-bearing zone of a target formation while inhibiting growth of the fracture into an adjacent water-bearing zone under or over the oil and/or gas-bearing zone, comprises creating a zone of increased in-situ stress a vertical distance adjacent a target interval and then creating a main fracture in the target interval by, for example, fracturing the target interval with enough fracture fluid and pressure to propagate the main fracture, inter alia, vertically to the zone of increased in-situ stress. When vertical growth of the main fracture reaches the limit set by the zone of increased stress, additional fracture fluid pumped into the target interval tends not to propagate the main fracture vertically beyond that limit and, instead, tends to propagate the main fracture more laterally and farther from the well. Such zone(s) of increased in-situ stress can be created above, below, or both above and below the target interval.

Abstract: A method of winning oil from a source via a bored well, wherein a magnetorheological fluid is introduced into the source via the bored well to reduce the water content of the oil won. Oil drilling is resumed in the presence of a magnetic field, thereby increasing the oil yield and/or decreasing the water content of the drilled oil.

Abstract: Methods and apparatus are provided which permit well testing operations to be performed downhole in a subterranean well. In various described methods, fluids flowed from a formation during a test may be disposed of downhole by injecting the fluids into the formation from which they were produced, or by injecting the fluids into another formation. In several of the embodiments of the invention, apparatus utilized in the methods permit convenient retrieval of samples of the formation fluids and provide enhanced data acquisition for monitoring of the test and for evaluation of the formation fluids.

Abstract: The present invention relates to foamed cement slurries, additives and methods. A foamed cement slurry of the invention comprises a hydraulic cement, sufficient water to form a slurry, sufficient gas to form a foam and an environmentally benign foaming and stabilizing additive comprising a mixture of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl betaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride and water.

Abstract: Method, apparatus and article of manufacture for monitoring and characterizing the operation of a transducer (i.e., motor or pump) downhole. In particular, transducer RPMs are determined by analysis of acoustic information. An acoustical source (signal generator) located on a downhole tool (e.g., a drill string) creates acoustic energy which is received and processed by a receiving unit, which may be located at the surface of a wellbore. The acoustical source is operably connected to the transducer, so that the frequency of the signal produced by the acoustical source corresponds to the speed of the transducer. The acoustic signal of the acoustical source may then be isolated from other acoustical energy produce by downhole equipment, such as a drill bit. Having determined transducer speed by isolation of the acoustic signal, other operating parameters may be determined. Illustrative operating parameters include torque, flow, pressure, horsepower, and weight-on-bit.

Abstract: The present invention involves a pack-off system for use in packing off an area of interest within a wellbore. The pack-off system comprises at least two packing elements disposed on a tubular body. The packing elements of the present invention comprise overlapping leaves which are pivotally mounted on the tubular body. The present invention further involves a method for using the pack-off system, wherein the packing elements are placed adjacent to an area of interest within a wellbore. The overlapping leaves of the packing elements are extended radially to effectively obstruct fluid flow in the annular space between the outermost portions of the packing elements and the wellbore. The bulk of the fluid introduced into the wellbore is trapped between the packing elements and is thereby forced into the area of interest.

Abstract: Methods and systems for optical endpoint detection of a sliding sleeve valve are disclosed. The system comprises fiber optic cable based sensors (e.g., fiber Bragg gratings or fiber optic coils) positioned in a recess within the valve's housing and affixed proximate to the ends of the cavity in which the sleeve travels. When the sleeve reaches the ends of the cavity, it imparts a stress onto an area of the housing, which preferably constitutes a protrusion within the cavity, which in turn stresses the sensor and changes its reflection profile. This change in reflection profile indicates that the sleeve has traveled to an end point inside the valve, and accordingly that the valve is fully open or fully closed.

Abstract: A spring centralizer device for supporting a tubular member spaced from the wall of a bore is made from a single piece of boron steel material. The spring centralizer device has first and second collars spaced apart along a longitudinal axis. Spring bow portions extend between the collars. As the device is made from a single piece of material, the material extends seamlessly from each collar portion through the bow portions so that there are no joins or points of weakness. Use of boron steel means that the device can be made by cold forming.

Abstract: A hydraulic drill string device can be in the form of a percussive hydraulic in-hole drilling machine that has a piston hammer (50) with an axial through hole (51) into which a tube (35) extends. The tube forms a channel for flushing fluid from a spool valve (62) and the tube wall contains channels (40) with ports (41,42) cooperating with the piston hammer for controlling the valve.

Abstract: The present invention generally relates to a connector arrangement for connecting a first tubular to a second tubular. In particular, the present invention relates to methods and apparatus for connecting the tubulars in such a way that the connection is prevented from becoming unmade in response to expansion of the tubulars. A connector mechanically mates a box end and a pin end of the tubulars together to form the connection. Additionally, mating castellations, surface finishes on the pin end and the box end, torque screws, and a variable pitch groove can provide resistance to relative rotation between the tubulars at the connection.

Abstract: A portion of at least one fiber is moved from a wellbore into a formation such that the portion is placed to conduct a signal responsive to at least one parameter in the formation. One particular implementation uses fiber optic cable with a process selected from the group consisting of a fracturing process, an acidizing process, and a conformance process.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: A method and apparatus are provided for drilling for petroleum. The method and apparatus circulate drilling mud through a particle separation apparatus that rapidly removes clay and other chemical additives. The drilling method and apparatus of the invention drastically reduces the amount of water required to drill a petroleum well, processes drilling mud at the well site, and produces water that can be broadcast on ground adjacent the well site, that can be introduced into deep water injection wells, or that can be given to livestock.

Abstract: In connection with a method and a tool for preparing a well for the production of hydrocarbons, it is aimed at perforating a casing portion (26) and working surrounding sediment (80) in a channel-forming manner. For this purpose the tool comprises a drilling means for drilling transverse holes through the casing wall when the tool (10), which is arranged to be raised/lowered and rotated about its longitudinal axis, shared by the casing (26), is placed in a fixed position within the well, through which transverse hole (40) and into surrounding sediment a jetting hose means (42,42a) is arranged to jet/dig its way in a channel-forming manner. The drilling and jetting hose means also have inactive stand-by positions protectively retracted within the tool housing (10a), from and into which they may successively be pushed forward into active working positions and again be withdrawn, as a channel (44) is completed in the sediment (80).

Abstract: An autonomous system for performing a well operation at a predetermined location in a wellbore comprises a tool string having at least one well tool, a motive device for traversing the wellbore, and a control system adapted to position the tool string near the predetermined location. The control system comprises (i) a sensing system for detecting mass irregularities in the wellbore and (ii) a processor system having a processor with memory for storing at least one well log. The processor acts under programmed instructions to compare sensor signals to the stored well log to determine a tool string position in the wellbore. The control system also contains circuits for controlling the operation of the well tool and the motive device.

Abstract: A novel concentric pipe joint restraint is disclosed. The restraint is specifically designed to resist axial movement of an inner spigot pipe relative to an outer socket pipe with which it has been joined. The restraint, which operates within the annulus, generally comprises a spigot wedge ring, a socket wedge ring, and one or more specially designed wedge housings. The spigot wedge ring features one or more spigot gripping protrusions which, upon contact, frictionally engage the spigot pipe. The socket wedge ring similarly features one or more socket gripping protrusions which, upon contact, frictionally engage the socket pipe. The wedge housings position the spigot wedge ring and/or the socket wedge ring so that the gripping protrusions grip the pipes, preventing axial movement (whether separation or compression).