Abstract: A hydraulic jar apparatus to be disposed in a drilling string embodying inner and outer telescopically arranged elements. Overlapping portions of the elements provide an annual chamber confining an operating liquid by an annular seal fixed to the outer element at the lower end of the chamber and an annular Polly Pack seal fixed to the outer element at the upper end of the chamber. A piston is extended radially from the inner element into the chamber and the chamber is divided by a cylinder on the outer element into low and high pressure sections. Impact shoulders are provided on the elements in axially opposed relation to produce a jarring blow and the elements are telescopically coupled by a hexagonal spline sub assembly.

Abstract: An improved type of hydraulic control cartridge with mounting structure and accessorial safety device for installation within both ends of reciprocative pneumatic actuators to permit a safe increase in their speed of operation. The safety device automatically stops the actuator if the hydraulic cartridge malfunctions.

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 shock absorbing apparatus for use in an earth boring drill string is disclosed herein. The shock absorber is of the type having a mandrel reciprocally mounted for rotation with a tubular body; a sealed chamber between the tubular body and the mandrel containing pressurized fluid for absorbing load and shock. Torque is transmitted between the mandrel and body by pins which are inserted in cavities formed by grooves on the exterior of the mandrel and the interior of the body. Means are provided to prevent pin rotation and to prevent the pins from contacting the groove edges to provide improved loading and wearing characteristics of the pins.

Abstract: Disclosed is a running tool for running sensitive well equipment into a well. Once the well equipment has been landed in the well, the running tool releases therefrom upon the application of a steady force. This abstract of the disclosure is neither intended to define the scope of the invention which, of course, is measured by the claims, nor is it intended to limit the invention in any way.

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 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 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 system for the transmission of data along a borehole during drilling operations which includes an acoustic transmitter receiver and mechanical filters. Data is acoustically propagated from the transmitter to the receiver along a portion of the drill string which is isolated from noise generating elements of the drilling system by means of the mechanical filters.

Abstract: Apparatus is disclosed for use in a drill string during rotary well drilling, especially of shallow holes such as blast holes, to absorb the shock loads imposed upon the drill bit and drill. A floating solid piston in an outer tubular body separates a gas chamber from a liquid chamber and equalizes the pressure between the two. A mandrel with large diameter bearing surfaces is carried reciprocally within the body, and has annular lubricating cavities separated from the liquid chamber. Lubricating passages include one in which a pressurized gas in a cavity supplies lubricant under pressure to the various bearing and sealing surfaces. Cylindrical pins inserted between the mandrel and the outer tubular body transmit torque between the body and mandrel.

Abstract: An apparatus is provided capable of absorbing shocks due to decelerating forces caused by landing of a marine riser on a spider resting on a rotary table. The apparatus includes a hydraulic shock absorber mounted on the rotary table which supports the spider on which the riser lands, the load and shock of the riser moving pistons in cylinders to force hydraulic oil in the cylinders through an orifice into an accumulator, effecting shifting of an accumulator piston against compressed air in the accumulator, which can exhaust through a pressure relief valve. The above action decelerates the riser and spider. Upon removing the weight of the riser from the spider, the compressed air in the accumulator, supplied from the suitable source, moves the accumulator piston back to its initial position, which acts through the hydraulic oil to effect upward return of the pistons to their initial positions. The apparatus permits lateral translation of the spider and also its tilting in all directions to limited degrees.

Abstract: A housing with a mandrel therein is adapted to be connected in a rotary drill string. The housing and mandrel are constructed and arranged to support the work load of the rotary drill string as well as dissipate both longitudinal and radial impact or shock loads that the drill string may encounter. The construction also includes means whereby radial impacts applied to the drilling assembly are connected or translated into longitudinal components of force so that various combinations of longitudinal and/or radial impact or shock loading of the drill string may be dissipated in a manner to inhibit damage to the drill string and its components.

Abstract: In accordance with an illustrative embodiment of the present invention as disclosed herein, a shock absorber adapted to be incorporated in a drill string includes axially splined housing and mandrel members having a helical coil spring reacting therebetween to absorb longitudinal vibration and shock loads and otherwise attenuate exciting forces generated by the drill bit. The coil spring has a low spring rate and is enclosed between the housing and a hollow flow tube that is slidably sealed with respect to the housing and the mandrel.

Abstract: A suction dredger, comprising a vessel and a suspension conveying conduit provided with a pump and having a nozzle suspended by means of at least one cable of a lifting device on the vessel is improved for preventing breaking of the cable or damage of other dredger parts. To this aim the lifting device comprises a cable length variator delivering cable and each time hauling essentially all delivered cable in work condition with a high cable tension being lower than the inadmissible cable tension, but being higher than a predetermined low cable tension, in order to prevent an inadmissible cable tension during a downward ground reaction upon the nozzle.

Abstract: In accordance with illustrative embodiments of the present invention disclosed herein, a shock absorber adapted to be incorporated in a drill string includes axially splined housing and mandrel members that enclose a resilient structure which absorbs longitudinal vibrations and shock loads and otherwise attenuates exciting forces generated by the drill bit. The resilient structure comprises inner and outer cylindrical torsion tube springs providing a low spring rate.