Abstract: An injection tool for use in injecting fluids into perforations of a production formation of an oil or gas well is mechanically set in the bore of the casing traversing the production formation, and mechanically releasable therefrom so that chemical treatment fluid can be injected between upper and lower packing elements into a single or a selected vertical group of perforations. The injection tool is connected to the tubing string by a circulation valve operable by rotational movement of the tubing string. Injection of the chemical fluid treatment is accomplished with the circulation valve in the closed position, while the circulation valve is opened to equalize tubing and annulus pressure whenever required.

Abstract: An apparatus for extracting a virgin fluid sample from a selected formation of subterranean well comprises an outer tubular housing disposed between two packing elements straddling the selected formation and having radial ports communicating with the annulus adjacent the selected formation. A hollow mandrel extends entirely through the length of the tubular housing, and the lower portions of such mandrel cooperate with the bore of the internal tubular housing to define a sample-collecting chamber. Fluid passage from the radial ports to the collecting chamber are blocked in the run-in position of the apparatus by an axially shiftable valve sleeve, which is shear pinned in a flow-blocking position during run-in of the tool. Fluid pressure is then applied to the bore of the hollow mandrel to shift the valve sleeve upwardly and remove the valve sleeve from its flow-blocking position, thereby permitting flow from the radial ports into the sampling chamber.

Abstract: A tubing trip tool for use in determining the extent of defects in tubular sections of a continuous tubing string used in subterranean oil and gas wells is disclosed. The tubing trip tool is mounted on a surface rig surrounding the tubing string and defects are magnetically detected during tubing removal from the well bore. The tool comprises a segmented expandable detector head containing elements for measuring average wall thickness and local and axially extending defects. The expandable head is spring loaded and pneumatically actuated. Coupling detectors are located on the ends of the head to count tubing sections and to detect the presence of obstructions on the tubing to prevent damage to the detector head.

Abstract: A method and apparatus for determining the extent of defects in ferromagnetic tubular elements comprising a continuous string for use in an oil or gas well is disclosed. The tubing trip tool measures tubing average wall thickness, local defects, such as corrosion pitting, and axial defects, such as sucker rod wear during removal of the tubing from the well. Tubing velocity is also measured, and couplings between tubing sections are detected and counted, in order to specify the axial location of defects on each tube, and also provide a profile of the condition of the overall string. A saturating magnetic field and a fluctuating magnetic field are applied to the tubing and the magnitude of the induced fields and the changes are measured to quantify defects in the tubing.

Abstract: A packer for effecting steam treatment of a production formation of a subterranean well comprises an insulated mandrel which is slidably inserted within the bore of an inner tubular body assembly. An outer operative tubular assembly surrounds the inner assembly and mounts a plurality of drag blocks, upper and lower cone elements, a plurality of radially displaceable slips cooperating with the upper and lower cone elements, and an outer packing element fabricated by an assemblage of high temperature resistant, non-resilient seal elements formed primarily of graphite. An inner packing element is provided in the inner tubular body assembly, utilizing additional high temperature resistant, non-resilient seal elements formed primarily of graphite, which sealingly engages the insulated mandrel.

Abstract: A pilot valve for effecting a control action selectively in response to the departures of the fluid pressure of a monitored fluid above or below a desired norm. Two axially spaced control fluid inlet ports in the valve body communicate with a valve chamber and a radially disposed fluid outlet port is located intermediate the two fluid inlet ports. Application of fluid to one fluid inlet port will result in the valve responding to an increase in fluid pressure above the desired norm while the application of fluid to the other port will result in the valve responding to a decrease in the monitored fluid pressure from the desired norm. Flow of control fluid from the selected inlet port to the outlet port is controlled by a spring biased spool valve which is axially shiftable within the central valve chamber by a piston responsive to the monitored fluid pressure.

Abstract: An improved concrete lining machine is provided for lining the walls of a bored tunnel. The machine typically consists of three separable machine sections each having a frame and a plurality of supporting plates rotatable in an endless loop chain. Fresh concrete is sealed from the second machine section by a plurality of adjoining main and auxiliary plates which remain in place relative to the concrete until the concrete is at least substantially cured. According to the method of the present invention, the first machine portion partially supports the bored tunnel walls, and a third machine portion partially supports the curing concrete. The cost of tunnel lining according to the techniques of the present invention has been substantially reduced, and the machine may be placed directly behind a tunnel boring machine.

Abstract: An improved hydraulic coupler suitable for interconnecting subsea fluid lines is provided with a highly reliable metallic seal between the male and female portions. A C-shaped metallic seal is radially compressed between the female and male coupler bodies, so that axial movement between these bodies does not effect sealing effectiveness. A floating retainer ring housed within the retrievable female body by a fixed retainer ring allows for radial misalignment between the coupling halves. The floating retainer ring thus becomes centered with respect to the male coupling body, while a metallic face seal provides sealing engagement between the floating and fixed retainers. Both axial and radial deviation between the coupling bodies is thus permissible, and the coupling can reliably seal fluid after repeated coupling and uncoupling operations.

Abstract: A fluid pressure activated firing head for a perforating gun disposed in a subterranean well by a packer is provided with a column of clean fluid overlying and filling the bore of the firing head but communicating with the casing annulus above the set packer. An annular fluid passage extends from the top of the clean fluid column through the set packer and ending in an inverted U-shaped annular passage. A pressure transmitting seal is mounted in the downwardly extending leg of the annular fluid passage to permit the entire fluid passage to be filled with clean fluid of a lighter density than the casing annulus fluids, thus insuring that casing annulus fluid can never enter the interior of the pressure activated firing head.

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.

Abstract: A self-cleaning probe for a drilling fluid or drilling mud density-testing apparatus comprises an elongated tube through which pressured air is supplied to a nozzle disposed in the mud-immersed end of the tube. A cleaning plunger is normally disposed in an axially spaced, inoperative position relative to the nozzle and is reciprocated by an actuator mounted on the other end of the tube to pass through the nozzle and thereby remove any deposits of congealed mud from the nozzle bore. In a preferred embodiment, a small quantity of water is introduced in the upper end of the tube concurrently with the actuation of the cleaning plunger. This ensures that the congealed mud in the nozzle bore will be sufficiently hydrated to be easily removed by the cleaning plunger. Additionally, the cleaning plunger may be passed through an elastomeric wiping element which removes congealed mud from the plunger before it is again retracted to its inoperative position relative to the nozzle.

Abstract: A method and apparatus for determining the extent of defects in ferrogmagnetic elements, such as tubing comprising a continuous string for use in an oil or gas well is disclosed. The tubing trip tool measures the depth of local defects, such as corrosion pitting, during removal of the tubing from the well. Tubing velocity is also measured, and couplings between tubing sections are detected and counted, in order to specify the axial location of defects on each tube, and also provide a profile of the condition of the overall string. A saturating magnetic field is applied to the tubing and a comparison of two derivatives of flux leakage is made to quantify defects in the tubing.

Abstract: A tubing trip tool for use in determining the extent of defects in tubular elements comprising a continuous string used in a subterranean oil or gas well during removal of the string from the well is disclosed. Local defects and axially extending defects, as well as the average wall thickness of the tubular elements, are measured. The position of the defects is determined by measuring the variable velocity of the tubular elements as they are removed from the well. A noncontact velocity detector comprises detector elements generating a first signal dependent upon an applied magnetic field and the velocity of the tubular elements. The first signal is compared to a signal dependent only upon the magnetic field generated in a second element. A pickup coil and Hall effect probes can be used.

Abstract: A drilling fluid density measurement system uses a continuously operating bubble measurement system for an oil or gas well. A microprocessor correlates the signal output from a differential pressure transmitter connected to a pair of self-cleaning pressure probes which are positioned in a circulating drilling fluid. By manipulating solenoid valves, the microprocessor controls the intermittent zeroing of the output signal from the differential pressure transmitter and controls a periodic level check to determine if the pressure probes are submerged in the drilling fluid.

Abstract: A multi-drop communication link, consisting of a master and a plurality of slaves is intrinsically safe for use in a hazardous environment. Slaves are in parallel and communicate with the master through transmit and receive shunt-diode safety barriers. An opto-coupler interface is provided between each slave and the transmit and receive circuits communicating with the master. The opto-couplers comprise infrared emitter-detector pairs which can be spaced apart by an intrinsically safe distance.

Abstract: Method and apparatus for matching the power output of a high slip motor to the demand requirement of a pumpjack unit. The stators of the high slip motor are automatically connected in various different configurations to provide the optimum torque as required by the pumpjack unit due to the downhole pumping conditions. A novel control circuitry is connected between the motor starter and the motor stators. The control measures the power drawn by the stators and selects the most optimum configuration thereof for the load required by the pumpjack. This selection operates the motor in the lowest possible torque mode, which is considered the best electrical and mechanical operation of the pumpjack apparatus.

Abstract: An apparatus for analyzing metal alloys includes an electronic unit connected to a hand-held probe unit. The probe unit includes a radiation detector enclosed in a detector housing and a radiation source enclosed in a source housing. The detector housing is generally cylindrical in shape and has an aperture formed in its sidewall. The source housing is formed as a hollow, generally right triangular prism with an open base attached to the detector housing over the aperture and tapering to a tip having an aperture formed therein. The triangular shape of the source housing permits contact measurements in hard to get at places. A shutter drive mechanism is utilized to move a shutter means between a first position blocking radiation and a second position passing radiation from the source to the aperture in the tip of the source housing.

Abstract: A valving mechanism for a cylinder-piston unit wherein the extreme positions of the piston are not positively controlled by a crankshaft or similar device. Inlet and exhaust valves are respectively mounted in a cylinder head and are operated by actuating rods projecting into the path of the piston.

Abstract: A sealing system for a valve disposed downhole in a subterranean well and subject to a high-temperature and high-pressure environment, comprises an annular valve seat defining a primary annular metallic seating surface surrounded by a groove within which is mounted a nonresilient, nonmetallic sealing element which is spring urged to project axially beyond the end of the primary sealing surface. The valve head is provided by a primary metallic sealing surface which, as the valve head moves toward engagement with the valve seat first engages the nonresilient, nonmetallic sealing element and deflects same axially and concurrently expands it radially outwardly so that the nonmetallic, nonresilient sealing element ends up engaging a cylindrical surface surrounding the primary sealing surface formed on the valve head.