Abstract: A roller cutter (28) of a drill bit (10) is retained on a journal (24) for rotation by a retainer ring (82) having external screw threads (88) which are threaded onto mating screw threads (108) on the roller cutter (28) for rotation therewith. The retainer ring (82) is mounted within a semicircular groove (68) on the journal (24) and has an inner periphery formed of a smooth arcuate surface contacting the annular groove at a position spaced at least 10.degree. from the entrance opening of the groove thereby to reduce bending stresses exerted against the root (74) of the groove (68).

Abstract: A drill pipe transfer arm supports the bottom portion of a drill pipe and positions it in relationship to the drill string to permit angle drilling with a tilted drill tower. The transfer arm is uniquely suited to circular carousels and features a drill pipe conforming saddle which permits close-quarter operation with a packed carousel.

Abstract: A pressure limiter for use with a positive displacement pump and an inflatable packer. The pressure limiter includes an outer housing with an inner mandrel disposed therein. Slidably disposed between the mandrel and housing is a generally annular piston. A spring biases the piston toward a closed position. Packer pressure acts upwardly on the piston tending to move it to an open position in which pump discharge pressure is relieved to a well annulus. A check valve prevents premature relief of pressure of the packer. Once the piston is in an open position, packer pressure will maintain it in the open position until pressure is relieved from the packer.

Abstract: A system for eliminating the need for one or more mud loggers on a drilling rig keeps track of the travel of drilling mud injected into the bottom of the well as it moves to the surface of the well with entrapped drill cuttings and gas so that for mud reaching the surface of the well, the system knows at what depth in the well the mud was injected. The system indicates to drill rig personnel when mud from preselected well depths reach the surface of the well and when to collect samples of drill cuttings strained from the mud in order to have the required samples representative of the preselected well depths. The system monitors the performance of well personnel in collecting samples by monitoring the time it takes to collect a sample after the indication that the sample should be collected.

Abstract: A rotatable liner hanger for an oil well with a supporting mandrel having an annular recess with upper and lower shoulders and a tubular housing and a bearing means disposed in the recess. The housing has elongated windows with side surfaces having tongue and grooves at an inclination angle of 15.degree. and elongated slip members with interfitting tongue and grooves along their side surfaces where the slip members are initially retracted within the windows of the housing and are extendible outwardly into load bearing support with a casing. A selectively actuated device controls the positioning of the slip members and an annular recess in the housing provides a bypass area when the slip members are extended.

Abstract: An inflatable borehole plug is disclosed, the inflation of which is achieved by chemical reaction of two co-reagents disposed therein which results in evolution of a gas. The borehole plug can be dropped or lowered down a borehole to a preselected position since the extent of gas-producing chemical reaction is able to be delayed following initiation of mixing of co-reagents, by delay means in the borehole plug, for sufficient time to enable placement of the borehole plug.

Abstract: Disclosed is a means for retaining drill chucks for down hole drills including a circumferential groove cut in both the drill chuck and the wear sleeve, into which it is inserted, in complimentary mating orientation whereby the circumferential groove forms a channel which is filled with ball bearings, for example through access ports provided in the wear sleeve. The ball bearings prevent uncoupling and may be removed readily thereafter permitting removal of the chuck.

Abstract: A close fitting piston of a material such as rubber is attached to the end of a rod string such as a sucker rod which is suspended inside a tubing string installed in an oil well. An orbiting mass oscillator is attached to the upper end of the rod string and is operated at a frequency such as to cause resonant standing wave vibration of the rod string. The piston member attached to the bottom end of the rod string is driven by the vibrational energy to in effect form an acoustical piston which is driven by the vibrational energy. This energy is coupled to the surrounding liquid and thence to the surrounding formation to effectively unclog the well and the casing string of contaminants which may be impeding the flow of effluent from the well. The piston means is made long enough so that it operates as an acoustic monopole with both ends of the piston being vibrationally in phase with the vibrational energy traveling in the surrounding liquid medium.

Abstract: A device for drilling lateral boreholes from a cased parent well comprises selecting and coupling means adapted to cooperate with a deflection unit placed within the parent well. The selecting and coupling means are mounted at the lower end of an extension unit formed by interassembled tubular elements. The upper end of the extension unit is rigidly fixed to a suspension swivel within the wellhead and at least one slip joint is interposed between two tubular elements. The internal diameter of each tubular element is such that a drilling packer can be housed within the tubular elements.

Abstract: A high energy gas fracturing tool for radially fracturing a rock formation in a well bore consisting of a cylindrical canister that is holed to pass gas and is for housing a stack of propellant modules that are selected to provide a desired burn rate when ignited. Each propellant module mating face is angled from the horizontal between forty-five (45) to seventy-five (75) degrees, and the modules are bonded together with an epoxy resin wherein propellant or explosive particles are mixed, the resin to exhibit burn characteristics similar to those of the propellant stack. The tool, additional to the propellant containing canister, an ignitor rod and explosive device for igniting the propellant stack, mounts a bull head end over a lower end and a reverse thruster assembly that is connected to the canister upper end.

Abstract: There is disclosed an apparatus including a tubing spool and tubing hanger which overcomes problems associated with servicing of oil and gas wells under pressure. In the invention, a tubing hanger can move through a tubing spool and be seated and sealed from the outside the tubing spool. The tubing hanger includes a flexible packing element with means for engaging and expanding the element to the tubing hanger in the tubing spool and a plurality of locking means adapted to secure the dognut in relation to the tubing spool.

Abstract: An orienting and circulating sub is disclosed for connection in an apparatus for angular drilling in the earth. The drilling apparatus comprises a drill string extending into a substantially vertical well bore in the earth supporting a fluid operated motor and drill bit at its lower end. The drill bit is supported for angular drilling by either using a bent sub for supporting the drilling motor or be using a drilling motor with a bent housing. A surveying tool is connected above the motor for determining and controlling the direction of drilling. A mule shoe keying sub is connected to the surveying tool for orienting the position of the motor in relation to said surveying tool. The orienting sub comprises a tubular housing formed in two sections threaded together with one end connected to the surveying tool by the mule shoe keying sub and the other end connected to the bent sub or to the bent motor housing.

Abstract: A drilling tool for use in drilling operations for providing shock absorption capability and lateral support to the rotary drill string. The telescoping axial load shock absorber is positioned immediately adjacent at least one lateral support provided by a reamer or stabilizer. The stabilizer preferably employs a removable fixed blade secured to the tool by an undercut groove. The roller cutter for a reamer is also mounted in a preferred unique manner with the mounting blocks secured in a recess having an undercut retainer portion in the event of bolting failure. The mounting's brackets may be formed integral of the tool body or attached by welding or the like. A preferred form of mounting a blade on a stabilizer tool is also disclosed.

Abstract: Percussion drill bit for rock perforators is provided whose frontal face is covered by a plurality of hard-metal studs, whereby a plurality of studs are positioned to form a group, there being several of these groups present and each of the so-called groups being at a distance from one another at least circumferentially and separated through circulation-medium channels, and further provided with at least one axial center channel located roughly in a center of the frontal face and opening into the circulation-medium channels, characterized in that each group consists of only one row of studs (1) arranged on sloped protruding drilling facets (4), in that the drilling facets (4) run against the rotation direction (A) of the drill bit, at an angle with respect to the radius, and in that the circulation-medium channels (2) formed in the frontal face widen starting from the center of the drill bit, radially towards the outside.

Abstract: A well pump assembly has a tube extending into the well for delivering water to a point below the pump to reduce the viscosity of the oil being pumped. The downhole motor that drives the pump is surrounded by a jacket. The tube that delivers the water extends to a point below the jacket to a cross-over member mounted to the lower end of the jacket, which directs the water upward and inward. The cross-over member also has passages that directs the production fluid upward and outward.

Abstract: An adjustable bent sub for use in directional drilling in earth formations comprises a first body member having a first body portion defining a first primary axis and a second body portion defining a first secondary axis disposed at a first offset angle with respect to the first primary axis, a second body member having a first body portion defining a second primary axis and a second body portion defining a second secondary axis disposed at a second offset angle with respect to the first primary axis, the second body member being adapted to be secured to the first body member such that the first secondary axis and the second primary axis are coaxial and define a common axis and the second body member is rotatable about the common axis. A device is provided for non-rotatably coupling the second body member to the first body member in predetermined angular relation about the common axis so as to provide a predetermined angular relationship between the first primary axis and the second secondary axis.

Abstract: Disclosed herein is an erosion resistant down hole rock drill bit which utilizes a radial distribution of carbide cutter bits or buttons about the exhaust hole. This minimizes carbide wash or removal of base metal which retains the carbide and thereby extends bit life.

Abstract: A road surface layer reproducing machine is characterized by its rotor unit which is provided with a mixing chamber housing the rotors for scarifying and mixing the asphalt pavement in an atmosphere of a high temperature higher than the temperature of open air to facilitate such a scarifying and mixing operation of the asphalt pavement, which mixing chamber is kept at such a high temperature by the operation of heating means such as a heater and a hot air blower, and is vertically driven through power cylinders.

Abstract: Methods and apparatus are provided for retrieving an inflatable packer of a type which may be passed through a small diameter tubing, seal against a relatively large diameter casing by passing fluid to the packer through a remedial tubing, and then be retrieved to the surface through the small diameter tubing. If the downhole equipment assembly becomes hung up during retrieval, fluid may be passed through the remedial tubing to release an upper portion of the packer actuator assembly from a lower portion of the packer actuator assembly. The released upper portion and remedial tubing may then be retrieved to the surface, and a conventional fishing tool utilized to subsequently retrieve the lower portion and the packer.