Abstract: Implementations of the present invention include a core barrel assembly including external fluid pathways extending generally axially long the outer surface of the core barrel assembly. The one or more external fluid pathways can allow for increased fluid flow around a latch mechanism. The increased fluid flow around the latch mechanism can allow the core barrel assembly to travel faster within the drill string, can allow drilling fluid to pass by the latch mechanism when engaged. Implementations of the present invention also include drilling systems including external fluid pathways, and methods of retrieving a core sample using such drilling systems.

Abstract: Embodiments of the present invention generally relate to extendable cutting tools for use in a wellbore. In one embodiment, a tool for use in a wellbore includes a tubular body having a bore therethrough, an opening through a wall thereof, and a connector at each longitudinal end thereof; and an arm. The arm is pivotally connected to a first piston and rotationally coupled to the body, is disposed in the opening in a retracted position, and is movable to an extended position where an outer surface of the arm extends outward past an outer surface of the body. The tool further includes the first piston. The first piston is disposed in the body bore, has a bore therethrough, and is operable to move the arm from the retracted position to the extended position in response to fluid pressure in the piston bore exceeding fluid pressure in the opening. The tool further includes a lock operable to retain the first piston in the retracted position; and a second piston operably coupled to the lock.

Abstract: A core barrel assembly having a driven latch mechanism that can lock the core barrel assembly axially and rotationally relative to a drill string. The driven latch mechanism can include a plurality of wedge members positioned on a plurality of driving surfaces. Rotation of the drill string can cause the plurality of wedge members to wedge between an inner diameter of the drill string and the plurality of driving surfaces, thereby rotationally locking the core barrel assembly relative to the drill string. Drilling systems including the driven latch mechanism and methods of using the driven latch mechanism are also described.

Abstract: A latch body for use in a drilling head assembly including a fluid control subassembly, a check valve element, and/or a hollow spindle. A distal end portion of the latch body includes a port section that defines a chamber for receiving the check valve element and promoting movement of the check valve element between a blocking position and an open position. The hollow spindle of the fluid control subassembly is operatively coupled to the chamber of the port section and supports the check valve element in the blocking position. A proximal end portion of the latch body supports the fluid control subassembly of the drilling head assembly in an operative position. The latch body includes male protrusions extending inwardly toward and spaced from a longitudinal axis of the latch body. A plurality of channels extend radially outwardly from the longitudinal axis of the latch body, spanning between adjacent male protrusions.

Abstract: Expandable reamers for enlarging wellbores include a tubular body and one or more blades configured to extend and retract. A sleeve member within the tubular body has open ends to allow fluid to flow therethrough. A fluid port extends through a wall of the sleeve member. A restriction member within the sleeve is movable between first and second positions. In the first position, fluid flow through the downhole end of the sleeve is generally unimpeded, and fluid flow through the fluid port is generally impeded. In the second position, fluid flow through the downhole end of the sleeve member is generally impeded, and fluid flow through the fluid port is generally unimpeded. The restriction member may be configured to move responsive to changes in the rate of fluid flow through the sleeve member. Methods of using such reamers are also disclosed.

Abstract: Expandable reamers for enlarging wellbores include a tubular body and one or more blades configured to extend and retract. A sleeve member within the tubular body has open ends to allow fluid to flow therethrough. A fluid port extends through a wall of the sleeve member. A restriction member within the sleeve is movable between first and second positions. In the first position, fluid flow through the downhole end of the sleeve is generally unimpeded, and fluid flow through the fluid port is generally impeded. In the second position, fluid flow through the downhole end of the sleeve member is generally impeded, and fluid flow through the fluid port is generally unimpeded. The restriction member may be configured to move responsive to changes in the rate of fluid flow through the sleeve member. Methods of using such reamers are also disclosed.

Abstract: An expandable drilling apparatus is deployed upon a distal end of a drillstring and includes a cutting head and a substantially tubular main body adjacent the cutting head providing a plurality of axial recesses configured to receive arm assemblies configured to translate between a retracted and an extended position. A flow switch actuates the arm assemblies when a drilling fluid pressure exceeds an activation value and the drilling apparatus includes a biasing member to reset the arm assemblies when the drilling fluid pressure falls below a reset value.

Abstract: In accordance with an embodiment of the present invention, a drilling tool includes a tubular body defining a longitudinal axial cavity extending therethrough and defining at least one cutter element recess. The drilling tool also includes a cutter element at least partially disposed within the at least one cutter element recess and includes at least first and second cutting arms at least substantially disposed within the cutter element recess in a retracted position. The first and second cutting arms are operable to move from the retracted position to an extended position in which the first and second cutting arms extend at least partially beyond a periphery of the tubular body. The first and second cutting arms and the tubular body enclose a space when the first and second cutting arms are in the extended position.

Abstract: An under reamer for expanding a borehole through an earthen formation is taught. The under reamer includes: a mandrel including an end for connection into a drill string and an opposite end and a housing including an inner bore, telescopically disposed over the mandrel and axially moveable relative to the mandrel but rotationally moveable with the mandrel. A plurality of under reamer arms are carried on the housing, the under reamer arms are formed as blocks including cutter-supporting portions in which poly-crystalline diamond compact cutters are mounted. The under reamer arms are moveable by driving the housing axially over the mandrel between a retracted position extending into the bore of the housing and an expanded position wherein the under reamers arms are pivoted out of the housing inner bore and supported therebehind by the mandrel such that the cutter-supporting portions are exposed for use to enlarge a borehole.

Abstract: A system is provided (1) for increasing the diameter of at least a portion of a well bore, the system being intended to be attached to a drill pipe (3), the system having a support element (10) bearing cutting arms (13, 14) which is movably mounted with respect to a body (4) and wherein the arms and the chamber (6) of the body (4) are designed so as to cooperated. A method is also provided for increasing the diameter of at least a portion of a well bore by drilling.

Abstract: The present invention generally relates to an apparatus and method of forming a wellbore. In one aspect, an expandable bit for use in a wellbore is provided. The expandable bit includes a body and a blade assembly disposed on the body. The blade assembly is movable between a closed position whereby the expandable bit has a smaller outer diameter and an open position whereby the expandable bit has a larger outer diameter. The expandable bit further includes a release assembly for providing a secondary means to move the blade assembly from the open position to the closed position. In another aspect, a method of forming a wellbore is provided. In yet another aspect, an expandable apparatus for use in forming a wellbore is provided.

Abstract: A drilling apparatus for underreaming includes a top sub, a pressure sleeve mated to the top sub, and a blade body mated to the pressure sleeve. A pilot bit is mated to the lower end of the blade body. A plurality of movable cutting blades are pivotably attached to the blade body by pivot pins. Each of the pins is inserted through the blade body and the cutting blade. Slidable covers, held in place by the pressure sleeve, are used to retain the pins. A mandrel is centrally positioned with respect to the pressure sleeve and the blade body and is axially movable therein. Each of the cutting blades includes an end which is operatively associated with channels transversely formed on one end of the mandrel. Movement of the mandrel in a first axial direction effects retraction of the cutting blades. Movement of the mandrel in a second axial direction effects extension of the cutting blades. The mandrel is held in its blade-retracting position by the biasing force of a spring.

Abstract: Borehole opener, particularly for enlarging this hole underneath a casing in the field of oil prospecting, comprising a body (2) of longitudinal axis (3), a duct (4) for drilling fluid, formed longitudinally in the body (2), and at least two hole-opening arms (5) which have an active part (7) equipped with cutting means (8), which are distributed symmetrically in the body (2) about the longitudinal axis (3), and which are arranged therein in such a way that they can be moved between a position of rest (9) in the body (2) and an active position (10) partially out of the body (2); in this hole opener in order to move it from the position of rest (9) to the active position (10), each arm (5) has a face (12), internal to the body (2), designed to be subjected directly, in the same way as an active face of a piston, to the pressure of the drilling fluid flowing through the body (2).

Abstract: The well reamer comprises a sub for attaching it to the drive means, a hollow housing with a central channel and radial openings in its side wall, projectable rolling cutters with shanks, mounted in the radial openings of the housing, and a mechanism for projecting the rolling cutters, including a piston and a member for locking the rolling cutters in their operating positions. The annular piston is connected with the housing for joint rotation therewith, and is regidly connected with the sub. The wall of the piston has radial passages made therein, establishing communication between its central channel and so annular space defined between the walls of the piston and of the housing. The member for locking the rolling cutters is accommodated with a clearance in the central channels of the piston and of the housing, and has an annular shoulder. The central channel of the piston defines a seat for engagement with the annular shoulder of the locking member.

Abstract: A hydraulically operated underreamer or reamer for enlargement of boreholes is to be connected to a rotating drill string. An outer movable cylinder extends the entire length of the reamer for protection of inner parts thereof. Cutter support arms are movable rectilinearly between an operative state whereat they extend from the cylinder and a closed state whereat they are completely retracted within the cylinder. Cutters are mounted on the support arms and are rectilinearly movable with support arms through openings in the cylinder.

Abstract: Borehole opener, particularly for enlarging this hole underneath a casing in the field of oil prospecting, comprising a body (2) of longitudinal axis (3), a duct (4) for drilling fluid, formed longitudinally in the body (2), and at least two hole-opening arms (5) which have an active part (7) equipped with cutting means (8), which are distributed symmetrically in the body (2) about the longitudinal axis (3), and which are arranged therein in such a way that they can be moved between a position of rest (9) in the body (2) and an active position (10) partially out of the body (2); in this hole opener in order to move it from the position of rest (9) to the active position (10), each arm (5) has a face (12), internal to the body (2), designed to be subjected directly, in the same way as an active face of a piston, to the pressure of the drilling fluid flowing through the body (2).