Abstract: An expandable reamer apparatus and methods for reaming a borehole are disclosed, including at least one laterally movable blade carried by a tubular body selectively positioned at an inward position and an expanded position. The at least one laterally movable blade, held inwardly by at least one blade-biasing element, may be forced outwardly by drilling fluid selectively allowed to communicate therewith or by at least one intermediate piston element. For example, an actuation sleeve may allow communication of drilling fluid with the at least one laterally movable blade in response to an actuation device being deployed within the drilling fluid. Alternatively, a chamber in communication with an intermediate piston element in structural communication with the at least one laterally movable blade may be pressurized by way of a movable sleeve, a downhole turbine, or a pump.

Abstract: An expandable reamer apparatus for drilling a subterranean formation may include a tubular body, one or more blades, each blade positionally coupled to a sloped track of the tubular body, a push sleeve and a drilling fluid flow path extending through an inner bore of the tubular body for conducting drilling fluid therethrough. Each of the one or more blades may be configured to ream a subterranean formation. The push sleeve may be disposed in the inner bore of the tubular body and coupled to each of the one or more blades so as effect axial movement thereof along the track to an extended position responsive to exposure to a force or pressure of drilling fluid in the flow path of the inner bore. Each blade may include one or more roller elements for reaming a wellbore.

Abstract: Expandable reamer tools include an outer body, a fluid passageway extending through the outer body, and at least one blade configured to slide relative to the outer body between a retracted position and an expanded position in a direction oriented at an acute angle of less than ninety degrees (90°) to a longitudinal axis of the outer body. In some embodiments, the tools may include a moveable inner sleeve member configured to selectively allow hydraulic fluid pressure within the fluid passageway to act directly on the at least one blade. Methods for enlarging a borehole using such expandable reamer tools and methods for removing such expandable reamer tools from a borehole are also disclosed.

Abstract: An expandable reamer apparatus for drilling a subterranean formation includes a tubular body, one or more blades, each blade positionally coupled to a sloped track of the tubular body, a push sleeve and a drilling fluid flow path extending through an inner bore of the tubular body for conducting drilling fluid therethrough. Each of the one or more blades includes at least one cutting element configured to remove material from a subterranean formation during reaming. The push sleeve is disposed in the inner bore of the tubular body and coupled to each of the one or more blades so as effect axial movement thereof along the track to an extended position responsive to exposure to a force or pressure of drilling fluid in the flow path of the inner bore. Other embodiments of the expandable reamer apparatus are provided.

Abstract: A downhole apparatus for engaging a borehole in a subterranean formation includes a tubular body having a longitudinal axis and a first bore, an actuation element having a second bore and is positioned within the first bore of the tubular body a drilling fluid flow path extending through the first and second bores, and a restriction element trap positioned within the second bore of the actuation element. The actuation element is configured to selectively isolate an operable component of the downhole apparatus from exposure to drilling fluid pressure within the tubular body and the restriction element trap is configured for retentively receiving a restriction element. A restriction element trap for use with an actuation element for retentively receiving a restriction element and an expandable reamer apparatus for enlarging a borehole in a subterranean formation are also provided. Further provided is a method of activating a downhole apparatus within a borehole of a subterranean formation.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The laterally movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The laterally movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The laterally movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or an adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or an adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: Enhanced stabilization is provided for an eccentric reaming tool when a pilot borehole is undersized with respect to a following pilot stabilization pad (PSP). Alternatively, offset of a rotational axis of at least a portion of the assembly including the reaming tool is employed to accomplish stabilization of the reaming tool. In either case, a reamed diameter larger than a physical diameter of the reaming tool may be drilled. More specifically, an enlarged PSP relative to pilot bit diameter or PSP offset or even pilot bit offset is employed in order to engage a PSP with the wall of a pilot borehole of greater diameter than a physical diameter of the pilot bit. The PSP or pilot drill bit, or both, may be laterally offset, angularly offset, or a combination thereof in order to effect substantially continuous PSP contact with the pilot borehole wall.

Abstract: A method and apparatus for reaming or enlarging a borehole with the ability to drill cement, cement float equipment, and debris out of a casing without substantial damage to the casing interior or the reaming apparatus. The reaming apparatus also provides enhanced protection from contact with the casing wall for selected structural features and elements thereof.

Abstract: Enhanced stabilization is provided for an eccentric reaming tool when a pilot borehole is undersized with respect to a following pilot stabilization pad (PSP). Alternatively, offset of a rotational axis of at least a portion of the assembly including the reaming tool is employed to accomplish stabilization of the reaming tool. In either case, a reamed diameter larger than a physical diameter of the reaming tool may be drilled. More specifically, an enlarged PSP relative to pilot bit diameter or PSP offset or even pilot bit offset is employed in order to engage a PSP with the wall of a pilot borehole of greater diameter than a physical diameter of the pilot bit. The PSP or pilot drill bit, or both, may be laterally offset, angularly offset, or a combination thereof in order to effect substantially continuous PSP contact with the pilot borehole wall.

Abstract: A method and apparatus for reaming or enlarging a borehole with the ability to drill cement, cement float equipment, and debris out of a casing without substantial damage to the casing interior or the reaming apparatus. The reaming apparatus also provides enhanced protection from contact with the casing wall for selected structural features and elements thereof.

Abstract: A rotary-type drill bit for drilling subterranean formations having areas or components having surfaces exhibiting a relatively low adhesion, preferably nonwater-wettable, surface over at least a portion thereof.

Abstract: A method for protecting integrity of a core sample during transport from a subterranean formation to the surface comprising: cutting a core sample from the subterranean formation using a drilling fluid; encapsulating the core sample with an encapsulating material that is separate from the drilling fluid and comprises a property which renders the encapsulating material capable of protecting the chemical integrity of the core sample during transport from the subterranean formation to the surface, wherein the property is other than a property selected from the group consisting of a viscosity which increases in response to a decrease in temperature and an ability to solidify in response to a decrease in temperature; and, transporting the encapsulated core sample from the subterranean formation to the surface.

Abstract: A superabrasive cutting element attachable to a drill bit for drilling subterranean formations is formed of a substrate and a superabrasive table with a three-dimensional interface comprising a continuous wave pattern extending about a central axis. Multiple outwardly directed arches of the wave pattern are oriented and configured to preferentially accommodate loading experienced by the cutting element during drilling to absorb and distribute stresses resulting therefrom. Thus, any tendency toward fracture and spalling of the superabrasive table and delamination thereof from the substrate, any of which may induce catastrophic failure of the cutting element, are substantially reduced. A rotary drill bit including such cutting elements is also disclosed.

Abstract: The present invention provides a method for protecting integrity of a core sample during transport from a subterranean formation to the surface comprising: cutting a core sample from the subterranean formation using a drilling fluid; encapsulating the core sample with an encapsulating material that is separate from said drilling fluid and comprises a property which renders said encapsulating material capable of protecting said chemical integrity of said core sample during transport from said subterranean formation to said surface, wherein said property is other than a property selected from the group consisting of a viscosity which increases in response to a decrease in temperature and an ability to solidify in response to a decrease in temperature; and, transporting said encapsulated core sample from said subterranean formation to said surface.

Abstract: The present invention provides a method for maintaining the mechanical integrity and for maximizing the chemical integrity of a core sample during transport from a subterranean formation to the surface. The method involves cutting and encapsulating a core sample with an encapsulating material that increases in viscosity or even solidifies, at temperatures slightly lower than those expected downhole, or relatively early in the transport process. A preferred encapsulating material contains at least one polyglycol or chemically modified polyglycol from the oxyalkylene polymer family. The specific formulation of the encapsulating material differs depending upon the expected downhole conditions. For example, the encapsulating material can include a thickener, a nucleating agent, and a water swellable material or another inert material that is capable of sealing the core sample against water.

Abstract: The invention is a coring device which has features to seal off from the well fluids prior to taking of the specimen. The apparatus can be hydraulically or pneumatically actuated to move an inner string which is connected to a core barrel. Prior to moving the core barrel, an outer tube is sealingly pushed into the formation. Once the outer tube has been set into the formation, the inner tube drives the core barrel into the formation, leaving behind a rabbit. A clam shell is located at the forward end which stays open as the core barrel is driven into the formation and closes as the core barrel is withdrawn into the outer tube to retain the core. The pneumatic or hydraulic pressure continues to be applied to the inner string as the core barrel is withdrawn into the outer tube. Upon full retraction of the core barrel into the outer tube, a ball valve is actuated to seal off the core barrel. At that time, the hydraulic or pneumatic pressure is removed and the apparatus is pulled to the surface.

Abstract: A closure mechanism for preventing fluid access to an inner tube of a core barrel assembly is disclosed in which the closure mechanism is configured to move from an open, or unoccluded, condition to an occluded condition in response to increased fluid flow rates and pressure differentials occurring at the closure mechanism. The closure mechanism is also configured to maintain occlusion of the inner tube under substantially all types of drilling conditions, and particularly those where conventional closure mechanisms may fail, such as in horizontal drilling. The closure mechanism generally includes a conduit structure associated with the inner tube, and having a seat, an occlusion structure, such as a ball, and releasing structure which maintains the occlusion structure in spaced relationship to the seat until increasing pressure differentials result in release of the occlusion structure to register with the seat.