Abstract: A blowout preventer (10; 110) adapted to be included in a drill string (11; 111) to isolate a downhole portion of an annulus (14; 114) between the drill string and a borehole wall (12; 112). The blowout preventer has a tubular body (16; 116) and an expandable packer means (22; 122) having an inactive or unset position permitting fluidflow through the annulus (14; 114), and a released, active or set position closing the annulus (14; 114). The tubular body (16; 116) has a through-bore (18; 118) aligned with a bore of the drill string and passageways (30; 130) parallel to the through-bore (18; 118) with fluid inlet ports (32; 132) arranged in a manner to be sealingly covered by the packer means (22; 122) in its unset position, and uncovered upon release of the packer means (22; 122) to permit it to expand into its sealing position closing the annulus (14; 114).

Abstract: A mud saver valve is described that features an outer housing that retains upper and lower valve pistons therewithin. The pistons coordinate to provide a check valve so that fluid, such as drilling mud, is permitted to flow in one direction while under pump pressure and works as a relief valve in the event of excessive wellbore pressure when the pump is turned off. Both pistons are provided with apertured plates that selectively define fluid passages through the valve. In the described embodiment, the valve also includes a frangible vent cap that is self-securing and easily replaceable. The cap permits venting of excessive downhole pressures.

Abstract: A bottomhole assembly (BHA) for use in well operations, with particular application to use in drilling with a downhole drilling motor and with coiled tubing and directional drilling, including a novel power pack, orienting tool, arrangement of bottomhole assembly tools, and method of use of the BHA for orienting while drilling.

Abstract: The present invention is directed to a method of cleaning a well riser. In particular, the method comprises the steps of suspending in a drill pipe from the surface a circulating tool in the well riser, and causing the circulating tool to axially collapse so as to open one or more radial outlets in the tool and allow cleaning fluid to be expelled out of the tool and impact on the inside of the well riser.

Abstract: Downhole flow pulsing apparatus comprises a housing (14) for location in a drillstring, the housing (14) defining a throughbore to permit passage of fluid through the housing. A valve (27, 30) is located in the bore and defines a flow passage (29, 31). The valve includes a valve member (27) which is movable to vary the area of the passage (29, 31) to provide a varying fluid flow therethrough. A fluid actuated positive displacement motor (15, 16) is associated with the valve member (27). In a preferred embodiment, the apparatus is provided in combination with a drill bit (5) and a pressure responsive device, such as a shock-sub (3), which expands or retracts in response to the varying drilling fluid pressure created by the varying flow passage area. The expansion or retraction of the shock-sub (3) provides a percussive effect at the drill bit.

Abstract: A method is disclosed for controlling the mud circulation system for deepwater marine drilling operations in which a drill string is run from surface facilities, through a blowout preventor and into a borehole. Mud is injected into the drill string, up a borehole and through the blowout preventor adjacent the sea floor. There the mud is withdrawn from a mud exit return line near the blowout preventor and the hydrostatic head from the mud in the drill string is isolated from the relatively lesser ambient pressure at the sea floor seen at the mud exit return line with a pressure activated drill string shut-off valve when mud circulation is interrupted. A drill string shut-off valve system for controlling the mud circulation system for deepwater marine drilling operations is also disclosed. Further, a method of well control to overcome formation pressure in a well control event is disclosed.

Abstract: A tool or sub for use in a well bore is adapted to manipulate the circulation path of fluid through a drill string or work string in which the tool is connected. The apparatus has a body member defining an axial flow path with one or more radial outlets that may be opened or closed by respective valve members in use.

Abstract: A system for controlling the weight on a rotary drill bit includes an hydraulic cylinder and piston assembly. Pressurized hydraulic fluid acting on the bottom of the piston provides an upward force on the drill string which is connected to the rotary drill bit. A profiled central drive shaft running through the piston conveys the rotary motion from a power swivel to a piston rod attached to the bottom of the piston which in turn is connected to the drill string.

Abstract: A two-way repeatable flushing device, comprising a flushing member for flushingupwards into the annular space between drill pipe and bore hole wall or lining pipe. Flushing is ensured by means of a remotely controlled valve and a balanced pressure control by associated valve parts and by means of pressure liquid to provide a controlled distribution of the flow downwards and upwards respectively, and the hydraulic conditions are thereby improved by hole cleaning during the drilling operation itself. The solution is particularly of interest for use in particularly complicated, long-range wells having significant paths in a horizontal direction. The flushing member ensures a satisfactory hole cleaning as a consequence of improved hydraulic conditions in the annular space.

Abstract: A mud saver valve adapted to be connected below a kelly including an elastomeric sleeve that opens and closes within a housing, the sleeve defining a flow passage within it and closing against a barrier located within the flow passage, the sleeve closing against the core at low positive differential pressures.

Abstract: An erosion resistant downhole diverter tool (210) comprises a generally cylindrical body (212) which may be configured as a slick sub or may include stabilizing blades (260). Located within the body 212 are a plurality of erosion-resistant, removable, cylindrical inserts (220). Each insert has an aperture (222) formed therein, aligned with a corresponding aperture (218) formed in the cylindrical body (212). Located within the apertures (218) in the cylindrical body (212) are pressure responsive, normally-closed valve assemblies (300), incorporating jet nozzles, which open in response to increased fluid pressure within the tool to provide fluid jets directed into the annulus surrounding the tool in a borehole or the like. The upper ends of the stabilizer blades (260) may include cutting structures to provide a back-reaming function.

Abstract: There is provided a circulating sub apparatus (50) having a tubular outer body member (51, 53, 54, 55, 56, 57) and a tubular inner body member (52, 65). The outer body member (51, 53, 54, 55, 56, 57) and the inner body member (52, 65) each have one or more holes (66, 68) substantially transverse to the longitudinal axis of the outer (51, 53, 54, 55, 56, 57) and inner (52, 65) body members. A displacement mechanism produces relative movement between the outer (51, 53, 54, 55, 56, 57) and inner (52, 65) body members such that the outer (51, 53, 54, 55, 56, 57) and inner (52, 65) body members may be repeatably moved between an aligned position, in which the one or more holes (66, 68) on the inner body member (52, 65) are aligned with the one or more holes (66, 68) on the outer body member (51, 53, 54, 55, 56, 57), and an obturated position, in which the one or more holes (66, 68) on the inner body member (52, 65) are obturated by the outer body member (51, 53, 54, 55, 56, 57).

Abstract: A downhole activated circulating sub is adapted to be interconnected between various tools installed on coiled tubing and placed into a wellbore; for example, between a coiled tubing/measurement while drilling tool and a downhole motor/drill bit for drilling a wellbore. The circulating sub can be repeatedly set and reset while the circulating sub is disposed in the wellbore. As a result, it is not necessary to retrieve the circulating sub to the wellbore surface for the purpose of resetting the sub. The circulating sub includes a latch mechanism which locks and latches the sub in either a set condition or a reset condition when a fluid is pumped through the circulating sub. When fluid flow through the circulating sub stops, the latch mechanism is unlocked and the circulating sub can change between the set condition and the reset condition.

Abstract: A pneumatic drilling chip removal system for removing drilling chips from a well bore, comprising sub-surface drilling equipment having a plurality of components and a drilling bit, a central passageway extending through the components and to the air jets in the drilling bit, wherein at least one component above the drilling bit in the sub-surface drilling equipment is a pneumatic component having an opening forming a pneumatic conduit from the central passageway to the annulus, a bypass valve disposed therein selectively permitting air flow from the central passageway to the annulus, forming a supplementary air source for removal of drilling chips from the well bore. Methods for using a pneumatic drilling chip removal system.

Abstract: A drill stem diverter tool for removing gelled drilling fluid and filter cake from the side of a well bore. The apparatus comprises a housing adapted to be connected into a drill string. The housing includes a plurality of diverter ports which communicate a central opening of the housing with a well annulus. A valve means which can be moved from a first position which blocks the diverter ports to a second position which opens the diverter ports is disposed in the central opening. The diverter ports are angled and offset from the center line of the housing so that the fluid exiting the ports creates a turbulent circular motion. A stop is provided to limit the movement of the valve means. The valve means may also be moved from its second position back to its first position to block communication to the well annulus through the diverter ports.

Abstract: An apparatus for drilling curved sections of well holes is described which includes a first tubular member having a bulbous first end, a second end, an exterior surface and an interior surface defining an interior bore. A plurality of pockets form a first annular ring in the exterior surface at the bulbous first end of the first tubular member. A second tubular member is provided having a first end, a second end, an exterior surface and an interior surface defining an interior bore. A socket is formed to accommodate the bulbous first end of the first tubular member at the second end of the second tubular member. The first end of the first tubular member extends into the interior bore of the second tubular member until the bulbous first end engages the socket. The bulbous first end of the first tubular member is capable of omnidirectional pivotal movement within the socket.

Abstract: A drill bit is mounted for percussive reciprocal movement in the lower end segment of a drill wear tube. A barrel is in the wear tube and defines a first and second series of exhaust ports. Channels in the barrel communicate the exhaust ports with discharge openings spaced about the head of the drill bit. An inlet opening in the face of the drill bit receives airborne earthen particles carried to an evacuation tube. Keys and keyways are disposed about the drill bit in parallel with the drill bit axis permitting a passageway of optimum size. Disposed within the barrel is a tubular piston which reciprocates in response to pressurized air alternately directed to the piston ends. The piston ends open and close the barrel exhaust ports. Internal surfaces of the piston cooperate with surfaces on the evacuation tube and on a press fitted sleeve thereon to direct compressed air to the piston ends.

Abstract: A downhole drilling device utilizing a spring-loaded sleeve within a casing for controlling circulation of fluid material. A plastic, i.e., deformable ball is used to block a flow opening in the sleeve for positioning the sleeve and aligning flow ports. Subsequently, the ball is deformed and the drilling operation continues. In one form, an expandable packer may be operated to close off the annulus about the casing.

Abstract: An apparatus for detecting and properly orienting a hydraulically-actuatable tool in a borehole and commencing drilling in a single trip of the drill string includes an MWD subassembly, for sensing the orientation, and a bypass valve for setting the hydraulically-actuatable tool once it is properly oriented and for thereafter conducting the drilling fluid to the cutter assembly. The method of setting a hydraulically-actuatable tool and commencing drilling in a single trip of the drill string includes the steps of running the hydraulically-actuatable tool into the borehole on a drill string which includes an MWD subassembly, sensing the orientation using the MWD subassembly, orienting the drill string to the desired orientation, and setting the hydraulically-actuatable tool.

Abstract: The present invention relates to a device for remote actuating an equipment through a variation of the flow of a fluid in a pipe. The device includes an adjusting throttle (2, 3; 52, 51) adapted for varying the opening of the passageway of said fluid through a hydrodynamic action. The device further includes delay timing for adjusting the throttle. The present invention further relates to a method for actuating at least one equipment. Application of the device and of the method is to the actuation of equipment adapted for controlling the trajectory of a wellbore.

Abstract: A pneumatic drilling chip removal system for removing drilling chips from a well bore, comprising sub-surface drilling equipment having a plurality of components and a drilling bit, a central passageway extending through the components and to the air jets in the drilling bit, wherein at least one component above the drilling bit in the sub-surface drilling equipment is a pneumatic component having an opening forming a pneumatic conduit from the central passageway to the annulus, a bypass valve disposed therein selectively permitting air flow from the central passageway to the annulus, forming a supplementary air source for removal of drilling chips from the well bore. Methods for using a pneumatic drilling chip removal system.

Abstract: Apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.

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.

Abstract: The invention relates to valves for wells.The overflow valve of a drill string comprises a hollow body (1) with side ports (2), a seat (4) which is part of the inner surface of the body (1), a shut-off element which is in fact an elastic sleeve (3) fitted with its one end in the body (1) and positioned therein with a gap (6). An effuser (7) is provided at the other end of the sleeve (3). Elimination of movable parts and units, increasing tightness of closing the passage for fluid to flow, decreasing hydraulic resistance of the overflow valve to the flow minimize wear and failure of the components and enhances operating reliability and durability of the valve.

Abstract: A flow control valve assembly is provided which, when connected to a rotatable drill string, prevents drainage of fluid from a standpipe and rotary hose of a drilling rig when fluid flow through the drill string is interrupted. The flow control valve assembly comprises a tubular body member or housing having a fluid flow passage extensive therethrough and a flow control valve supported within the fluid flow passage of the tubular body member. The flow control valve, which is a self-contained pressurized unit, is provided with an annular pressure cavity so that the flow control valve can be selectively opened and closed in response to pressure differential between the annular pressure cavity and the pressure of fluid in the fluid flow passage of the tubular body member.

Abstract: Apparatus is disclosed for controlling the power supplied to a drill bit by a downhole fluid powered motor to prevent the motor from rotating the bit at high speeds when there is little or no weight in the bit while maintaining full circulation through the fit. Apparatus also disclosed for restricting the flow of drilling fluid of the drill pipe when circulation is fully or partially lost.

Abstract: An apparatus is disclosed for use in a drill string 10 to prevent separation of a lower tubular member 16 from an upper tubular member 15 by a rotational force applied from a down-hole motor 22. The down-hole motor 22 is rotated by drilling fluid pumped from the surface, through a passage formed within the drill string 10, and into the down-hole motor 22. A valve 36 is positioned in the passage in the drill string 10 and has a first operating position adapted for passing the drilling fluid to the down-hole motor 22, and a second operating position adapted for substantially blocking the drilling fluid from being delivered through the down-hole motor 22. The value is of a two piece construction, having a first body 44 connected to an upper tubular section 14 and a second body 46 connected to the down-hole motor 22.

Abstract: A mud saver valve in which a cylindrical resilient sleeve is pressed against an inner tubular member by a pressurized gas to prevent flow from above the valve to below the valve at low pressures, and which is fully opened for free flow at higher pressures.

Abstract: An adaptor for drilling strings has a head, sleeve and mounting block assembly to secure a drill bit to a drilling string. By reverse rotation of the drilling string, the sleeve is movable between a first position, where pressurized air from the drilling string is directed to the drill bit, to a second position, where the air is directed to the drill hole above the adaptor to clear debris from the hole. Teeth at both ends of the drill assist the adaptor to clear the hole as the drill string is rotated and retracted from the hole.

Abstract: An actuator for an appliance associated with a ducted body, through the duct of which flows an incompressible fluid, includes a differential piston axially moveable within the duct and operatively connected to the appliance. The piston has a tubular shape and a central bore which includes a first profiled throttling portion the minimum internal diameter of which is smaller than the internal diameter of the duct. A protruding profiled element secured in the duct body is disposed coaxially with the piston and cooperates therewith for selectively increasing the loss of head of the incompressible fluid as it flows in the direction of circulation. A spring is arranged between the piston and part of the drill-string for biasing the piston in a direction of movement opposite the direction of circulation of the incompressible fluid. A measurement device is provided for measuring the pressure of the incompressible fluid at the first end of the drill-string.

Abstract: A wire line core barrel inner tube assembly has a latch body with a miximum diameter portion providing a shoulder seatable on a drill string landing ring and a fluid bypass channel extending through the maximum diameter portion and a valving assembly. The valving assembly includes a resilient valve seat in the bypass channel and a ball seatable on the valve seat to block fluid flow in a downward direction through the channel, movable upwardly off the valve seat from the seated position to permit fluid flow through the seat in the opposite direction and movable through the seat to a channel open condition after a preselected fluid pressure has been exerted on the ball in a direction to move the ball from the ball seated position and through the valve seat.

Abstract: An improved drill pipe assembly that is formed as a concentric walled pipe having both an axial and an annular space therethrough, and the pipe section includes means for selectively communicating the adjoining annular spaces through the series of respective box end/pin end joints whereby equipment compartmentation, conductor traverse, ballast containment, gas pressurization and weight addition can be effectively utilized in controlled manner. The pipe is assembled by threaded engagement of the pin end joint to each of an outer pipe and an inner pipe, and subsequent threaded joinder of the concentric pipes to a box end joint while also utilizing an intermediate double-threaded sleeve between the inner pipe threads and the box end collar threads.

Abstract: Flow pulsing apparatus is adapted to be connected in a drill string above a drill bit. The apparatus includes a housing providing a passage for a flow of drilling fluid toward the bit. A valve which oscillates in the axial direction of the drill string periodically restricts the flow through the passage to create pulsations in the flow and a cyclical water hammer effect thereby to vibrate the housing and the drill bit during use. Drill bit induced longitudinal vibrations in the drill string can be used to generate the oscillation of the valve along the axis of the drill string to effect the periodic restriction of the flow or, in another form of the invention, a special valve and spring arrangement is used to help produce the desired oscillating action and the desired flow pulsing action.

Abstract: An adaptor for drilling strings has a head, sleeve and mounting block assembly to secure a drill bit to a drilling string. By reverse rotation of the drilling string, the sleeve is movable between a first position, where pressurized air from the drilling string is directed to the drill bit, to a second position, where the air is directed to the drill hole above the adaptor to clear debris from the hole. Teeth at both ends of the assist the adaptor to clear the hole as the drill drill string is rotated and retracted from the hole.

Abstract: An actuator for an appliance associated with a ducted body, through the duct of which flows an incompressible fluid, includes a differential piston axially moveable within the duct and operatively connected to the appliance. The piston has a tubular shape and a central bore which includes a first profiled throttling portion the minimum internal diameter of which is smaller than the internal diameter of the duct. A protruding profiled element secured in the duct body is disposed coaxially with the piston and cooperates therewith for selectively increasing the loss of head of the incompressible fluid as it flows in the direction of circulation. A spring is arranged between the piston and part of the drill string for biasing the piston in a direction of movement opposite the direction of circulation of the incompressible fluid. A measurement is provided for measuring the pressure of the incompressible fluid at the first end of the drill string.

Abstract: An improved drill pipe assembly wherein each pipe section is formed as a concentric walled pipe having both an axial and an annular space therethrough, and the pipe section includes means for communicating the adjoining annular spaces through the series of respective box end/pin end joints whereby equipment compartmentation, conductor traverse, ballast containment, gas pressurization and weight addition can be effectively utilized in controlled manner.

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: An earth drilling apparatus has a pneumatic motor operated earth drilling tool, a valve assembly connected to the motor, and a drill string connected to the valve and to a source of pneumatic fluid. The drilling tool has an earth drilling bit and a rotor/stator motor section to apply a rotational force to rotate the bit at the bottom of the string. The valve assembly is disposed between the drilling tool motor and the source of pneumatic fluid and controls the flow of pneumatic fluid to the tool. The valve assembly has a pneumatic pressure-operated valve which is operable in response to the pressure of pneumatic fluid in the drill string to be opened to permit flow of pneumatic fluid to the tool at a predetermined operating pressure to transmit an initial pulse of pneumatic fluid to initiate operation of the motor. The valve is kept open at a lower pressure than that required to open it.

Abstract: A manually operated downhole for an underground earth boring apparatus having a pneumatically operated earth boring tool. A drill pipe is connected to the tool and to a source of pneumatic fluid. A valve is positioned in the drill pipe substantially adjacent to the tool between the tool and the source of pneumatic fluid. This downhole valve controls the flow of pneumatic fluid to the tool. The valve is operable in response to pushing or pulling on the drill pipe.

Abstract: A downhole drilling device utilizing a spring-loaded sleeve within the casing for controlling circulation of fluid material. A plastic, i.e., deformable ball is used to block a flow opening in the sleeve for positioning the sleeve and aligning flow ports. Subsequently, the ball is deformed and the drilling operation continues. In one form, an expandable packer may be operated to close off the annulus about the casing.

Abstract: A new and improved air motor operated rotary earth drilling tool for use with a source of high pressure, high volume compressed air has a circulation control housing, a motor housing, a reduction gear housing, and a bearing housing connected longitudinally in series. The circulation control housing is connected to high pressure, high volume, compressed air and has an outlet opening into the motor housing, and an exhaust opening for discharge of compressed air for flushing cuttings and debris from a bore hole which is controlled by longitudinal movement of an inlet tube. The motor housing has a motor chamber and a sliding vane rotor with a rotary shaft extending into the reduction gear housing. A planetary reduction gear receives the rotor shaft and has a low speed, high torque output shaft extending into the bearing housing. A passageway conducts compressed air around the planetary reduction gear for cooling.

Abstract: Stopper, for cable passages or conduits, having a first chamber placed in said passage, said chamber comprising at least one bearing surface placed in this passage and adapted to cooperate with a closure element, a second chamber opening into the first chamber, said closure element being housed in said second chamber in a first position of the stopper, and means for moving the closure element in the first chamber to a second position of the stopper, where the cable is withdrawn from the passage, further comprising a separating member, situated between said first chamber and said second chamber, this member being adapted for controlling the movement of the closure element from the second chamber to the first chamber.

Abstract: To control the locking of a cable boring corer (1), a control device (30) is used, comprising a deflecting casing (33), a sleeve (31) and a piston (32), which are movable in relation to the deflecting casing (33). The piston (32) is able to be rendered integral in a lower position, under hydraulic pressure, with the sleeve (31) by a finger (43). When the hydraulic pressure is released, the sleeve (31), which is integral with the piston (32), is brought into an upper position which allows the circulation of a boring liquid through the deflecting casing (33) towards a boring crown (4).

Abstract: Flow pulsing apparatus is adapted to be connected in a drill string above a drill bit. The apparatus includes a housing providing a passage for a flow of drilling fluid toward the bit. A turbine in the housing is rotated about an axis by the flow of drilling fluid. A valve is operated by the turbine to periodically restrict the flow through the passage to create pulsations in the flow and a cyclical water hammer effect to vibrate the housing and the drill bit during use. A cam is provided for effecting reciprocation of the valve along the axis of rotation of the turbine to effect the periodic restriction of flow.

Abstract: The device has, inside a duct (11) through which flows an incompressible fluid, a first profiled throttling element (17), a differential piston (10) subjected on one side to the pressure upstream of the profiled element (17) and on the other side to the pressure reduced by the element (17), a profiled surface (18) on the piston on the side subjected to the reduced pressure and a second profiled element (16) which are intended to interact to reduce the passage of fluid as a result of the movement of the piston in a first direction and increase the loss of head substantially, and a spring (15) returning the piston (10) in its second direction of movement. The device can serve particularly for actuating a stabilizer of a set of drill rods. In this case, the differential piston has inclined slopes.

Abstract: A simple and economical device is placed in a drill string to provide a pulsating flow of the pressurized drilling fluid to the jets of the drill bit to enhance chip removal and provide a vibrating action in the drill bit itself thereby to provide a more efficient and effective drilling operation.

Abstract: A drilling fluid pulse generator for use above a drill bit to produce pulsations in drilling fluid flow. An autocycling valve briefly interrupts the flow of fluid to bit jets to reduce the effective hydrostatic pressure at the drilling face and to hydraulic energy in the drill string to thoroughly scour the hole face when the briefly closed valve reopens. An alternate configuration provides a bypass route for fluid diverted from the bit, and the bypass includes jet nozzles to add energy to the return fluid stream to further reduce the effective hydrostatic pressure at the drilling face.

Abstract: A vibratory earth penetrator employing a high pressure air distributor and an oscillating mechanism has the ability to dig down to underground utilities and contact those utilities without damaging them. The invention includes a hollow elongated tube having a plurality of air lances at the bottom end thereof. The air is preferably distributed to the air lances by an air distributor in a criss-cross sequence. An oscillating eccentric weight is synchronized with the air distributor to enhance the digging effect of the device. The penetrator is supported by a boom which includes an automatic tension device for providing sufficient upward force to keep the penetrator in the vertical attitude while allowing the weight of the penetrator to provide enough force to permit the device to dig into the ground. Since the digging action is accompanied by very little downward force, it is possible to contact underground utilities without hurting them.

Abstract: A transformable circulation tool for reversing the path of drilling fluid at the drill bit without removing the drill string from the borehole annulus is provided by a substantially hollow body having a chamber with external ports disposed between a section of the body having a through passage and a by-pass passage in combination with a diverter mounted on a telescoping member having means for engaging the body during drilling and disengaging the body for rotation of the diverter with respect to each of the passages. A seal is rotatably mounted to the substantially hollow body between the ports to divide the well borehole into an upper conventional flow portion and a lower portion where the flow of the drilling fluid can be reversed upon command from the surface.

Abstract: An annulus access valve system having a plurality of valves installed in, and forming a part of, a drill string in a well bore whereby fluid may be pumped into the annulus through the valves individually or in combination as desired. Each valve has a valve body connected to the drill string in which defines a longitudinal opening therethrough and a transverse port therein interconnecting the longitudinal opening with the annulus. A longitudinally slidable valve seats on a replaceable valve seat defining a closed position of the transverse port in the valve. The valve sleeve is biased in the closed position by a spring. An actuator, uniquely sized for a specific valve in the drill string, is utilized to engage the valve sleeve and move it to an open position by hydraulic pressure applied thereabove so that fluids may be pumped down the drill string through the transverse port into the annulus. A flow control valve is positioned in the actuator so that some fluid may be directed therebelow as desired.