Abstract: A wireline supported mechanically operable packer device (10) for use in a drill string (DS) casing (C) and attached core drill bit (B) raised off the bottom of a borehole and testing the formation below has a housing (12) adapted to engage an arresting internal shoulder (S) of the core drill bit (B). A hollow inner mandrel (40) slideable in the housing has attached thereto a packer seal cup (P) an O-ring seal (P) expander (50) weight means (60) and wireline means (70) (80) moveable between stops (16) (18) determining the extended and contracted positions thereof relative to the housing.

Abstract: There is disclosed a shock sub for incorporation in the lower part of a drill string for damping oscillations of the bit and drill string during drilling. The shock sub incorporates a spring assembly including a multiplicity of substantially annular ring springs that exhibit a spring rate of less than about 25,000 pounds per inch of deflection.

Abstract: A method and apparatus is disclosed for eliminating vertical motion of a downhole tool in a subsea borehole as the tool is being operated by a drill string from a floating vessel. A vertical motion elimination means is incorporated into the drill string at a point which will be adjacent a blowout preventer stack on the marine bottom when the downhole tool is positioned at a desired point in the borehole. The vertical motion elimination means is comprised of a sleeve which is rotatably mounted on the drill string at a fixed vertical position. The sleeve is adapted to be engaged by the blowout preventer stack to fix the sleeve against vertical movement with respect to the preventer. Since the sleeve, itself, is fixed against vertical movement on the drill string, that portion of the drill string which lies below the preventer (hence, the downhole tool) will also be fixed against vertical motion within the borehole.

Abstract: Adjustable torsional type latching means (5) for triggering a mechanical well jar tool comprises torsionally actuated gear racks (20,22) including acme threads or teeth which extend axially on opposite adjacent side portions of telescopic parts (1,2). The gear rack teeth which mesh in the latched position have incline tooth faces that can be disengaged by applying a strong axial force which torsionally stresses and rotates a torsion sleeve (16) portion of one telescoping part (1) and gear rack (20) thereon away from the other part (2) and gear rack (22). Upon release of the latching device (5) the telescopic parts (1,2) of the well jar and the kinetic energy stored therein are freed for a limited longitudinal jarring movement. The torsion sleeve portion (16) has an end portion connected to the other telescopic parts by a second slot-spline-gear (15) of relative short axial length, which serves as a torque support in the latched position and becomes deengaged during a jarring stroke.

Abstract: A method of and apparatus for drilling directional well bores is disclosed in which the well bore or a portion thereof is drilled along a line that follows, as close as possible, a preselected catenary curve. An extensible joint located between a stabilizer just above the drilling bit and a stabilizer spaced from the bit stabilizer is used to cause the bit to tend to increase the dip angle of the well bore at an increasing rate.

Abstract: A shock absorber assembly adapted to be used with a drill string dampening intermittent shocks and vibrational forces encountered with a drill string, the shock absorber assembly including a mandrel, a tubular body reciprocally mounted with respect to the mandrel, and a dampening device including an annular chamber adapted to be filled with a compressible fluid and a flexible wall with the mandrel adjacent the annular chamber for permitting flexure of the mandrel as needed for dampening.

Abstract: A drill string splined resilient tubular telescopic joint for balanced load deep weel drilling comprises a double acting damper having a very low spring rate upon both extension and contraction from the zero deflection condition. Stacks of spring rings are employed for the spring means, the rings being either shaped elastomer-metal sandwiches or, preferably, roller Belleville springs. The spline and spring means are disposed in an annular chamber formed by mandrel and barrel members constituting the telescopic joint. The chamber containing the spring means, and also containing the spline means, is filled with lubricant, the chamber being sealed with a pressure seal at its lower end and an inverted floating seal at its upper end.A prototype includes of this a bellows seal instead of the floating seal at the upper end of the tool, and a bellows in the side of the lubricant chamber provides volume compensation.

Abstract: A shock absorbing tool is provided for connection to a drill column. The drill column includes a drill bit and is positioned in a bore formed in the earth. The shock absorbing tool is an integral, resilient cylindrical member having a number of open sections formed in the cylindrical member. Pairs of open sections are interconnected by slots. Pairs of open sections are longitudinally spaced along the periphery of the cylindrical member. The longitudinal distance between pairs of open sections and the circumferential distance between open sections of each pair of open sections vary. Upon application of dynamic axial and torsional loads to the drill column, the shock absorbing tool absorbs these loads through deflection of the resilient tool such that the slots close and the stress produced by the dynamic loading is carried about the periphery of the open sections.

Abstract: An apparatus is described for forceably pulling a well casing down into a drilled hole from the casing bottom end during a percussion drilling procedure, through use of the percussion drill tool. An anvil is fixed to the casing and projects inwardly to coact with the hammer surface on a precussion bit. The bit includes an interlock feature that allows selective disengagement with the anvil and allows the bit to be lowered past the anvil for drilling purposes. The anvil is situated above the drive shoe along a lower casing section. The lower casing section acts as a material accumulator, cooperating with the drilling bit and anvil shoulder to seal drilled areas and facilitate removal of drilled material from the drilled hole.

Abstract: A novel shock sub is disclosed for use in a drill string for absorbing longitudinal and impact loads. A tubular housing is provided for connection to one part of a drill string and a tubular mandrel extends into the housing for longitudinal sliding movement with an outer end portion for connection to the other part of the drill string. The mandrel and housing define an annular cavity when assembled. The mandrel has two slots, positioned 90.degree. apart circumferentially extending for length of the annular cavity. Annular spring washers positioned in the annular cavity are of a size having a sliding fit on the outside of the mandrel and inside the housing. The spring washers are each corrugated in a wave configuration and with a tab of a size fitting one of the mandrel slots and are placed on the mandrel with alternate ones having tabs fitting in one of the slots and the others having their tabs fitting another mandrel slot.

Abstract: A well jar having an elongated body with an axial passageway and threaded connections for assembly into a string of well pipe. The body has a tubular mandrel slideably mounted within a tubular barrel with the annulus therebetween exposed to well fluid. Fluid seals in the annulus provide an isolated chamber containing a latch whereby the mandrel and barrel are selectively released for delivering an impact to the wellpipe. The improvement to the jar comprises a plurality of elongated, resilient vibration snubbers integrally carried by the mandrel and aligned longitudinally in the annulus between the mandrel and the barrel. The snubbers slideably engage the barrel throughout its telescopic movement along the mandrel. The snubbers are circumferentially spaced apart about the mandrel with the intervening spaces forming flow channels in the annulus to accommodate well fluid flows when the jar is mounted in the string of well pipe being rotated in the well bore.

Abstract: For use in a string of drill pipe terminating in drill collars and a drill bit, a shock sub is disclosed which, in the illustrated and preferred embodiment, incorporates telescoping upper and lower mandrels. The upper mandrel incorporates a pin connection and supports concentrically deployed, inner and outer tubular sleeves defining an internal cavity. The lower mandrel incorporates an upstanding sleeve which telescopes into the cavity between the sleeves of the upper mandrel. A two-chamber fluid damping system constrains movement of the lower mandrel sliding in the cavity of the upper mandrel. The two chambers are defined by meshed splines which permit telescoping movement, but which prevent relative rotational movement.

Abstract: A direct drive for a drill bit in a drill string has a fluid-operated motor within a drive section connected by a gear section to a bearing section whose inner tube is coupled to the drill bit to accommodate axial displacement of the drill bit within the outer tube, spring elements are braced against a radial bearing for the inner tube which has at least one axially defined race. The coupling between the inner tube and the gearing also accommodates such axial displacement and a reservoir for oil is located between the drive and gear sections so that oil can be fed to the gearing, the bearings and to an axial bearing in an annular oil-filled space between the drive and gear sections.

Abstract: A shock absorber assembly for absorbing shocks encountered by a drill string wherein the shock absorber assembly is for use with a drill string having a working fluid therein and includes a body member affixed to the drill string, a mandrel mounted for reciprocal longitudinal movement with respect to the body member and a fluid dampening member floated within the central bore of the body member in engagement with the body member and the mandrel for absorbing shocks transmitted between the body member and the mandrel.

Abstract: A downhole tool, comprising, a first cylindrical body member having a longitudinally extending annular cavity disposed therein, and including a relief port for communicating the cavity with a space outside of the tool, the space being filled with a first fluid, a cylindrical extension member having a first end slidably received in the annular cavity and having a second end extending longitudinally from the annular cavity, and an annular floating seal, slidingly disposed in the annular cavity between the relief port and the first end of the cylindrical extension member, for sealingly engaging radially inner and outer surfaces of the annular cavity and for separating a second fluid in the annular cavity between the floating seal and said cylindrical extension member from the first fluid. The downhole tool including the described floating seal structure is utilized for the testing of subsurface formations.

Abstract: A drilling riser between a subsea wellhead and a floating platform has a slip joint in its upper end. A chamber is formed within the slip joint and supplied fluid pressure to develop a tensioning force on the upper end of the riser as the floating platform cycles vertically under the influence of heave and tidal forces.

Abstract: A reciprocating rotary drill bit is disclosed to include a coupling member for coupling the drill bit to a source of drill bit drive power and a cutter member for drilling into a workpiece. The coupling member and the cutter member are slidably associated and include overlapping protruding portions which delimit the upward and downward travel of the cutter member with respect to the coupling member. The slidable association permits reciprocation of the cutter member with respect to the coupling member as the drill bit is rotated into the workpiece. The coupling member also includes protrusions which extend into grooves defined in the cutter member to rotationally secure the two members whereby the cutter member rotates when the coupling member rotates.

Abstract: This turbo-coring device comprises a tubular body provided with a coring bit and surrounded by a following pipe provided by a reaming bit. The tubular body is connected to the turbine through a fluid distributor having a side opening for discharging above the following pipe in the annular space between the device and the borehole wall a fraction of the fluid leaving the turbine, while the remaining fraction feeds the tubular body.The following pipe is connected to the outer wall of the fluid distributor through releasable bayonet type latching means.Means are provided for automatically closing the fluid discharge opening when the lower part of the tubular body becomes obturated by ground formations and an annular sealing packer is positioned between the tubular body and the following pipe.

Abstract: A shock absorber assembly for absorbing shocks encountered by a drill string having a working fluid flowing therethrough wherein the shock absorber assembly includes a housing affixed to the drill string, a mandrel mounted for reciprocal longitudinal movement with respect to the housing, and a fluid dampening member replaceably sandwiched between the mandrel and housing for absorbing shocks transmitted between the mandrel and the housing during drilling operations.

Abstract: Earth drilling hydraulic shock absorber having an anvil reciprocally mounted in a casing and operatively connected with a plurality of independently operating pistons, the anvil being reciprocally mounted within the casing through a spline connection with unidirectional sealing means for equalizing pressure across the sealing means with the hydrostatic pressure in a borehole for retaining a lubricating fluid around the spline connection and to prevent abrasive matter in drilling fluid from coming in contact with the spline connection. The anvil of the shock absorber may include a reduced effective pressure area so that the anvil engages the first piston at a lower downweight.

Abstract: A blow out preventor assembly for attachment to the drill stem and being placed within the drill casing during well operations provides a bottom seal assembly having an attachment for slideably attaching the bottom seal assembly peripherally to a section of drill stem with the bottom seal assembly having at least one flow opening allowing oil, gas and drilling fluids to pass therearound. The upper portion of the bottom seal assembly forms a valve which cooperates with a provided port-ring mounted above the bottom seal assembly and having an outer diameter substantially equal to the diameter of the casing. The port-ring forms a flow closure between the drill stem and casing, and has at least one flow opening therethrough and a valve seat at the valve opening adapted to receive the valve portion of the bottom seal assembly. Upper and lower seat rings provide gravitational supports to the port-ring and bottom seal assemblies respectively.

Abstract: This device comprises a resilient stress-responsive member interconnecting two conduits which can be respectively coupled to upper and lower portions of the downhole assembly, and are surrounded by a protecting sleeve making up with one of said conduits, the lateral walls of an annular space. Annular elements secured to a first of said lateral walls, and slidable on the second of said lateral walls, form the end walls of said space and an intermediate annular piston integral with the second lateral wall, and slidable on the first lateral wall, divides the annular space into two annular chambers communicating respectively with the inner and outer spaces of the downhole assembly of the drill string, and having operative cross sections selected so as to compensate for the axial loads due to the hydrostatic pressure and bottom effect applied to the stress-responsive member.

Abstract: A conventional type of impact rock drill is modified to include a fluid reservoir, valve and piston arrangement whereby each impact stroke of the driver ejects water at high pressure from the cutter bit, thereby increasing the mechanical cutting through hydraulic action of a small volume of high pressure jet of water.

Abstract: A drill string splined resilient tubular telescopic joint for balanced load deep well drilling comprises a double acting damper having a very low spring rate upon both extension and contraction from the zero deflection condition. Preferably the spring means itself is a double acting compression spring means wherein the same spring means is compressed whether the joint is extended or contracted. The damper has a like low spring rate over a considerable range of deflection, both upon extension and contraction of the joint, but a gradually then rapidly increased spring rate upon approaching the travel limits in each direction. Stacks of spring rings are employed for the spring means, the rings being either shaped elastomer-metal sandwiches or, preferably, roller Belleville springs. The spline and spring means are disposed in an annular chamber formed by mandrel and barrel members constituting the telescopic joint.

Abstract: A double acting damper for use in rotary drilling includes a splined tubular telescopic joint and employs plural paralleled stacks of double acting series stacked roller Belleville spring washers in an annular pocket between the inner and outer tubular members of the joint. The springs, spline and telescopic bearings are in an oil filled volume sealed from the outside by a pressure seal at the lower end of the damper and a floating seal at the upper end. Electric and magnetic means are provided to check on the condition and quantity of the lubricant.

Abstract: Well bore drill string shock absorber device for absorbing drill bit vibratory displacement shock, contemplating a pair of slidably, e.g. telescopingly, associated longitudinal elements, one of which is connectable to a drill string therabove and the other of which is connectable to a drill bit therebelow, such elements being interengageably interconnected for common rotation about a longitudinal, e.g. well bore, axis and for selectively limited relative reciprocal displacement longitudinally with respect to each other along such axis, and such elements together defining a shock absorber work chamber within longitudinal confinement wall portions thereof, e.g. an annular cylindrical chamber, of varying selective maximum and minimum operative longitudinal dimension and corresponding volume in dependence upon such displacement of the elements and in turn of such wall portions, and temporarily internally compressible and resilient shock absorbing means, e.g.

Abstract: An index mandrel body, which connects with a well string in a borehole, is received by a tubular body have a plurality of splines, which slidably engage teeth on an indexing sleeve rigidly affixed inside the mandrel said splines receiving seatable lands rigidly affixed inside the tubular body, said lands being so spaced as to be able to pass between the splines so that the body becomes fully rotatable, said invention being adaptable for use in compression or tension application to off shore drilling, as well as on land drilling.

Abstract: There is disclosed a shock sub for incorporation in the lower part of a drill string for damping oscillations of the bit and drill string during drilling. The shock sub incorporates a spring assembly including a multiplicity of substantially annular ring springs that exhibit a spring rate of less than about 25,000 pounds per inch of deflection. This is a continuation of application Ser. No. 849,718, filed Nov. 8, 1977 now abandoned.

Abstract: Vibratory drill apparatus is disclosed which is adapted for automatic self-balancing to compensate for variations in hardness of the material being drilled and/or dulling of the cutting blades which occurs during the drilling operation. The apparatus includes a tubular casing adapted to be connected to a rotating shaft and a drill assembly comprising a plurality of coaxially extending pipe members, each being located one within the other, the upper region of the drill assembly being received within the lower region of the casing. A drill head is defined at the lower region of the drill assembly. The pipe members are interconnected such that they are mutually fixed to each other for simultaneous rotation about their axis and such that each pipe member is free to move in the axial direction relative to the other pipe members.

Abstract: In accordance with an illustrative embodiment of the present invention, a shock limiting apparatus for mounting an instrumentality in a drill collar comprises piston and cylinder means subject to hydrostatic well fluid pressure for preventing longitudinal movement of the instrumentality within the drill collar unless a predetermined level of deceleration is exceeded, and a combination of hydraulic damping and Coulomb friction means for dissipating kinetic energy of the instrumentality in a substantially uniform manner when applied deceleration exceeds said predetermined level.

Abstract: A downhole weight control device is described for connecting to the upper end of a downhole, pneumatically-operated, impact rock drilling tool for applying a downward force on the tool sufficient to maintain the drill bit in the closed working position. The weight control device has a piston member that has an effective area related to the surface area of the hammer piston in the drilling tool to effectively counterbalance an upward force of the tool tending to lift the tool. The control device also prevents exerting excessive weight on the drill bit. The control device has means for automatically decreasing the working pressure should the drill string be fed for a period of time at a rate greater than the penetration rate of the tool.

Abstract: A tool having a low spring rate deformable element and a relatively long stroke is provided. The deformable element comprises a stack of alternating non-deformable metal washers and deformable elastomer rings extending throughout the length of the element chamber. The element washers and rings are substantially out of contact with the side walls of the mandrel and barrel, so that each segment of the element experiences the total shock load. The spline and deformable element are in an oil bath--the annular space between mandrel and barrel is sealed at the upper end by a fixed seal and at the lower end by a floating seal, so that the pressure internal of the chamber is equalized with the bottom hole pressure internal of the tool. Thus pre-loading of the element by the bottom hole pressure is avoided.

Abstract: An improved roof drill bit and roof drill driving assembly which is characterized as a "hands off" type in which the drill, driver, and drill extension are designed and assembled to have a stability which enables the operator to avoid guiding the drill with his hands. An improved drill bit prevents plugging of the assembly when used with suction systems and provides a heavier wall construction. Special adaptors are provided for driving drills and drill extensions.

Abstract: An axially extensible telescoping joint is employed in a directional drilling string to reduce the number of times for a given footage of well drilled that the wireline from the downhole survey or steering tool to the surface readout must be tripped through the string for adding more drill pipe. By drilling the first half of a drilling sequence with the telescoping joint collapsed, and then the second half of the sequence with the telescoping joint extended, twice the conventional footage can be drilled between wireline trips, and two stands of drill pipe can be added rather than the conventional single stand each time the wireline is tripped.

Abstract: A telescopic shock absorber for incorporation in a drill string connected to a rotary bit for drilling a bore hole in earth formations, the shock absorber including a single spring assembly which is compressed downwardly when sufficient downwardly directed drilling weight is transmitted from the drill string through the shock absorber to the drill bit, and which is compressed upwardly when the internal drilling fluid pressure in the shock absorber fully overcomes the downwardly directed drilling weight, assuring that the spring assembly is in its compressed condition when the shock absorber is telescoped or extended, enabling it to absorb shocks and vibrations incident to the drilling operation and under both conditions.

Abstract: A floating cushion sub for connection to the rotary power head of a drill rig has a mandrel section connectable to a drill string and an outer housing section connectable to the power head. The mandrel and the housing have mating, axially extending splines permitting relative axial movement while also transmitting torque from the power head to the mandrel. Mandrel axial movement is limited by a cap member and by an internal shoulder in the housing. A resilient cushion adjacent the shoulder dampens vibrations when the mandrel and housing are compressed together and a similar cushion adjacent the cap member dampens vibrations when the mandrel and housing are at full extension. The axial movement of the mandrel relative to the housing improves the function of making or breaking the threaded connections with the drill string by permitting proper coordination of the mating thread pitches and reduces the chance of cross-threading.

Abstract: A drill string shock absorber has a dual spring system for absorbing vibrations and shock loads during rotary well bore drilling operations. A first spring acts in compression when sufficient weight is set down on the drill bit through the shock absorber to overcome the fluid pressure forces tending to extend the shock absorber, and a second spring acts in compression when the weight applied to the bit through the shock absorber does not overcome the fluid pressure forces. A splined connection transmits torque to the shock absorber during drilling operations, and seals are provided between the telescopic shock absorber components for confining therein a body of lubricant, the pressure of which is equalized with the pressure of drilling fluid flowing through the shock absorber.

Abstract: A drill string protecting axial shock absorbing sub which is relatively short and rugged and comprises inner and outer telescopically intersplined tubular elements forming therebetween an annular shock absorbing cushion confining piston chamber which is filled with a tightly packed suspension of 3/8" polyurethane pellets in a highly heat resistant lubricant such as "Mobil #1 Synthesized Engine Lubricant".

Abstract: A hydraulic shock absorbing method for protecting the drill bit and drill pipe in rotary earth drilling comprising the steps of slidably moving an anvil connected to a drilling bit in a casing in response to increased down weight on the drill bit and sequentially transmitting further increases in the down weight and shocks from the anvil to a plurality of independently operating hydraulic pistons slidably mounted within the casing when down weight on the drill bit exceeds increasing predetermined amounts to activate the pistons in sequence. The drilling fluid within the casing is transmitted to first pressure areas on the anvil and the plurality of pistons and the drilling fluid is passed through the drilling bit to provide a pressure drop and then communicated to second pressure areas on the plurality of pistons.

Abstract: A shock sub for a well drilling string comprises a tubular housing adapted to be connected to one part of a drill string and a mandrel extending longitudinally into the housing and having an end portion adapted for connection to another part of the drill string. The mandrel and housing are shaped to define a non-circular annular cavity there between when assembled together. A compressible elastic metallic spring means is positioned in and substantially fills the non-circular annular cavity and is compressible longitudinally, radially and circumferentially to absorb longitudinal, radial and torsional vibration and impact loads and to transmit rotary movement between said housing and mandrel for imparting rotation from one part of the drill string to the other part connected by the drill sub. The spring means is preferably a knitted wire fabric or rope compressed into a compact mass capable of spring deflection in longitudinal, radial and circumferential directions relative to said shock sub assembly.

Abstract: A shock absorbing apparatus for earth boring drilling is disclosed herein. The shock absorber is of the type having telescoping members with a sealed chamber containing pressurized fluid between the members for supporting load and absorbing shock. The members have axial passages for the passage of high pressure air to the bottom of a borehole to remove cuttings. A tube is connected to one of the members and inserted in telescoping relationship into the axial passage of the other member to transmit the circulating air. The seals of the tube are protected from the heat of the circulating air by a liner disposed concentrically in the tube. The liner is cylindrical and of lesser diameter than the inner diameter of the tube to create an annular air space for thermal insulation.

Abstract: A vibration isolator includes telescoping tubular mandrel and barrel members between which torque is transmitted by an internally splined urethane bushing affixed to the cylindrical interior of the steel barrel and a urethane layer over the splined outer surface of the steel mandrel. Axial loads are transmitted in both directions between shoulders on the mandrel and barrel through two annular urethane members, one for each direction, disposed in annular pockets between the mandrel and barrel, which have greater radial thickness than do the rings, allowing room for deformation of the rings by axial loading. A replaceable sliding seal between the upper end of the mandrel and the barrel retains drilling fluid passing through the isolator. A sliding bearing between the mandrel and the lower end of the barrel cooperate with the seal at the upper end of the mandrel to take bending moments.The urethane annuluses are shaped, e.g.

Abstract: An earth boring assembly is provided with a hammer member at its leading end for impacting through an earth formation to form a boring therein. An expander cone is attached rearwardly of the hammer to expand the boring which has been formed by the hammer and drag pipes are connected to follow the hammer into the boring. Clamping means interposed between the expander cone and the drag pipe operate to automatically effect frictional locking engagement between the hammer and the drag pipe when the expander cone and the drag pipe are moved toward each other and to automatically release the frictional engagement when the members are moved away from each other. The clamping means may specifically comprise an annular slotted ring having wedge-shaped outer surfaces by means of which the ring is caused to become clamped and released about the hammer.

Abstract: A shock absorber assembly has an outer body connectible at one end in a well drill string and an inner body connectible at one end in the well drilling string, with the bodies telescopically coengaged. Between the bodies is an annular space, filled with hydraulic fluid and containing a pressure equalizing annular piston. Stacked sets of dished-spring washers are disposed in coengaged frictional relation to form parallel-acting columns in the annular space between the two bodies. The equalizing piston is exposed to the pressure of drilling fluid inside the inner body, in one form, and outside the outer body, in another form. Another equalizing piston defines between the bodies a fluid filled chamber containing torque transmitting means for causing the bodies to rotate as a unit during drilling operations while allowing telescopic extension and retraction of the bodies. Telescoping of the bodies causes fluid transfer through restricted passages to dampen the telescopic motion.

Abstract: A shock absorber from an oil well drill string mounted therein adjacent its drill bit to cushion drill bit impacts in hard formations and having an elongate tubular mandrel, for connection with said bit, slidably mounted in and drivingly connected to an elongate tubular housing coupled in the drill string. Tubular housing is composed of upper, intermediate and lower tubular sections, preferably; the uppermost has a bore complementary to and slidably engaged by upper packing means on upper end of mandrel, intermediate section has a bore complementary to and in slidable engagement with the mandrel and the lowermost has an upper bore complementary to and slidably engaged by downwardly biased lower packing means slidably confined upon mandrel and a lower bore complementary to mandrel with slidable drive connection between mandrel and housing therein.

Abstract: A drilling jar to be installed in a set of drill collars in a drill string is disclosed. In the illustrated embodiment, first and second tubular members telescope relative to one another. At the upper end of the lower tubular member, a set of protruding lugs match shoulders having undercuts which permit relative rotation of the two tubular members through part of a turn, thereby permitting the two members to axially telescope whereby locking or unlocking the telescoping movement is controlled. The lower tubular member has an upwardly facing shoulder which is abutted against the lower end of the upper tubular member. This permits the two to be reciprocated and banged together to create a jar for the drill string. When the string is jarred, the drill string can be jarred loose. the apparatus further includes a packer around a pipe positioned in the upper end of the upper tubular member.

Abstract: Disclosed is a motion compensator to permit relative movement between an underwater well installation and a vessel on the water surface. The motion compensator includes telescoping elements, seals between the telescoping elements and ports to permit lubrication of the seals. A method of using the motion compensator is also disclosed. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

Abstract: An hydraulic shock absorber for protecting the drill bit and drill pipe in rotary earth drilling consists of a casing with an upper sub mounted in its one end for connection to a string of drill pipe. An anvil is slidably mounted on the other end. A plurality of hollow pistons are slidably mounted inside the casing. The pistons each have a hollow sleeve portion extending in sealing relationship through seating rings mounted on the inside of said casing. The pistons also have a radial flange portion at their upper end slidably sealing with the walls of the casing and a fluid passage extends through the wall of the casing between the flange portion and the seating ring.

Abstract: A sampling drill comprising a plurality of drill rods coupled together to form a drill stem suspended from a drill head, each of the drill rods comprising a pair of substantially concentric tubular members defining an inner central passage and an annular passage, the lower end of the drill stem being fitted with a drill bit having an inner chamber adapted to be connected to the inner central passage of the drill stem, and one or more passages adapted to be connected at one end to the annular passage in the drill stem and at the other end to discharge into the inner chamber, the inner chamber being provided with openings located adjacent the cutting edges of the drill bit so that material cut by the drill bit can pass into the chamber, and means for shutting off the inner central passage to prevent material entering the inner chamber of the drill bit and entering the inner central passage.

Abstract: A shear sub for installation in the drill string used to rotate a drill bit in the drilling of wells includes a mandrel extending upwardly for connection to the drill string. A housing slidably enclosing the mandrel extends downwardly below the mandrel and is threaded for connection directly, or indirectly, through joints of drill pipe to the drill bit. Rotation and longitudinal movement of the housing relative to the mandrel during drilling is prevented by shear pins which engage the housing and the mandrel to hold the housing in a position in which lugs extending inwardly therefrom are directly above and in alignment with splines extending outwardly from the mandrel. If an obstruction to drilling occurs that results in excessive torque on the drill string, the shear pins are sheared. On lifting and rotating the drill string, the mandrel moves upwardly relative to the housing whereupon the lugs interlock with the splines to allow rotation of the drill bit as it is lifted off bottom.