Abstract: A susbsea well has communication passages to enable annulus pressure surrounding inner and intermediate strings of casings to be monitored at the surface. The passages both have outlets that allow communication to the tree assembly for monitoring. In one embodiment, the passage outlets are located in the bore of the high pressure well head housing and communicates to the tree assembly along an isolation sleeve. In another embodiment, the passage outlets are located on the exterior of the high pressure wellhead housing and communicate through a flying lead coming down from the tree. In another embodiment, the passage outlets are located on the exterior of the high pressure wellhead housing and communicate to an upward facing connection which is stabbed with a downward facing connection coming down from the tree.

Abstract: The invention concerns a device for driving into the marine subsurface, in particular at great depths exceeding a thousand metres, a tubular tool for soil sampling or for measuring said soil characteristics. The invention is characterised in that the tubular tool (1) to be driven into the marine subsurface is secured to a base plate for positioning on the sea floor, and the device comprises at least a fluidic actuator (16), capable of being controlled from the surface, which is fixed to said base plate comprising a piston (4) moving in a cylindrical annular chamber (3) with an axis oriented parallel to the axis (y′y) of the tool (1) penetration, driving in the tool (1) depending on the discharge of intake of the fluid which is produced in said chamber (3), said piston (4) being subjected to the hydrostatic pressure prevailing at the depth where the device has been lowered by being in communication with the marine environment by its side external to said chamber (3).

Abstract: Methods and apparatus are provided which permit well testing operations to be performed downhole in a subterranean well. In various described methods, fluids flowed from a formation during a test may be disposed of downhole by injecting the fluids into the formation from which they were produced, or by injecting the fluids into another formation. In several of the embodiments of the invention, apparatus utilized in the methods permit convenient retrieval of samples of the formation fluids and provide enhanced data acquisition for monitoring of the test and for evaluation of the formation fluids.

Abstract: A horizontal Christmas tree is adapted for ESP/HSP or downhole sensor deployment by a coiled tubing hanger 38 received in the tubing hanger 12. Coiled tubing 40 suspends downhole equipment such as ESP 60, and carries power/signal lines. These lines are connected to an external line 58 via a transition connector 46 in a tubing access plug 44 provided in an internal tree cap 32. A debris cap 50 is provided with a further connector 52. Self orientating wet mate connectors 48, 54, 56 are provided between the connectors 46, 52 and external line 58. The coiled tubing hanger and/or tubing hanger may be provided with flow by flutes or holes (78, 80 FIGS. 4 and 5) sealable by a separate adapter plug (88, FIG. 5) above the coiled tubing hanger. Flow test procedures are also disclosed.

Abstract: Methods and apparatus are provided which permit well testing operations to be performed downhole in a subterranean well. In various described methods, fluids flowed from a formation during a test may be disposed of downhole by injecting the fluids into the formation from which they were produced, or by injecting the fluids into another formation. In several of the embodiments of the invention, apparatus utilized in the methods permit convenient retrieval of samples of the formation fluids and provide enhanced data acquisition for monitoring of the test and for evaluation of the formation fluids.

Abstract: A well data monitoring system which enables annulus pressure and other well parameters to be monitored in the outer annuli of the well casing program without adding any pressure containing penetrations to the well system. This non-intrusive approach to monitoring pressure and other well parameters in the annuli preserves the pressure integrity of the well and maximizes the safety of the well. In the preferred embodiment an intelligent sensor interrogation system which can be located externally or internally of the pressure containing housing of the wellhead is capable of interrogating and receiving data signals from intelligent well data sensors which are exposed to well parameters within the various annuli of the well and wellhead program.

Abstract: A method for logging, controlling, or monitoring a subsea well or group of wells through a path not within production tubing is disclosed. Preferred embodiments of the present invention allow logging tools, wire rope, optic fibers, electrical cables, monitoring and measuring instruments and other items known to those skilled in the art of oil and gas production to be disposed into the well without interfering with the flow path through the production string. In another aspect of the invention, a preferred embodiment includes the mooring or tethering of an instrument pod over the subsea well. The instrument pod is designed provide on-board data storage, data processing, data receiving, and data transmission equipment, such that data from the well can be transmitted back to a receiving network where said data may be stored and processed into useful information for reservoir operators.

Abstract: A horizontal spool tree assembly 10 is provided for supporting a production tubing string 22 within a well below a BOP. The spool body 12 includes a laterally extending passageway 36 which is in fluid communication with a similar laterally extending passageway 34 provided in a tubing hanger 20. The tubing hanger includes a central bore for fluid communication with the production tubing string, and a workover flow path 30 extending axially through the tubing hanger, with a workover valve 32 provided for controlling the fluid flow in the workover passageway. An annulus port 70 extends laterally through the spool body, and an annulus valve 72 controls fluid flow through the annulus port.

Abstract: A system that is usable in a subsea well includes a tubular string that extends from a surface platform toward the sea floor. The string has an upper end and a lower remote end that is located closer to the sea floor than to the platform. At least one sensor of the system is located near the remote end of the string to monitor deployment of subsea equipment.

Abstract: The invention comprises a tubing assembly for use in testing an unconsolidated open-hole portion of a well bore located below a cased portion of the well bore and a method of using the assembly. The tubing assembly comprises an elongated tubing string extending from a well surface into the unconsolidated open-hole portion of the open hole, an open-hole packer mounted on the tubing string for use in sealingly engaging the unconsolidated open-hole portion of the well bore, a casing packer mounted on the tubing string between the open-hole packer and the well surface for sealingly engaging the cased portion of the well bore and a sand control device connected to the tubing string below the openhole packer. The assembly may further comprise additional open-hole packers and sand control devices mounted on the tubing string. Segments of the tubing string may be retrievable. The assembly may have one or more tubing disconnects mounted to the tubing string to disconnect segments of the tubing assembly.

Abstract: A method and apparatus for sensing the profile and position of a well component in a well bore and transmitting this information to a surface mounted display unit to aid an operator in performing subsea well operations. The apparatus includes an instrumented flange with appropriate end connections to allow connecting the flange between the annular preventer and the drilling riser. The instrumented flange is sufficiently long to allow a first plurality of sensor units to be arranged circumferentially around the axial bore of the flange in a single plane and a second plurality of sensor units to be arranged in a helical pattern along the axis of the flange. The output signals of the sensor units are processed at a signal processing unit which then transmits the information to a display unit at the surface.

Abstract: A method and apparatus for sampling fluids from an undersea wellbore comprising a self-propelled underwater vehicle and a collection and storage device; so that samples may be recovered directly from the wellbore and subsequently analyzed to determine the characteristics of the oil produced from separate wells.

Abstract: A system for controlling fluid flow from multiple isolated producing zones in a well is provided. Components of the system are placeable in and retrievable from bottom entry side pocket mandrel sections permanently installed in a production tubing string in the well. These components provided are sensor modules, isolation valve modules, power modules, control modules, hydraulic pump control modules and packer modules which are carried by the production tubing string. Control signals for modules are developed either downhole or at the surface and modules may be placed or retrieved through the production tubing without pulling the production tubing from the well.

Abstract: A well assembly for extracting production fluids from at least one production zone of at least one well includes a production pipe for transporting fluid downstream to a surface, a packer for defining the production zone, and a fiber optic sensor package disposed substantially adjacent to a downstream side of the packer. The fiber optic sensor package measures parameters of the production fluid and communicates these parameters to the surface to determine composition of the production fluid entering the production pipe through each production zone. The production pipe has a zone opening for allowing the production fluid to enter the production pipe and a control valve for controlling the amount of production fluid flowing downstream from each production zone. The production pipe control valve is adjusted to optimize fluid production from the particular production zone of the well based on fluid parameters measured by the fiber optic sensor package.

Abstract: A control module system provides convenient and economical operation of downhole tools, which operation is controllable from a remote location. In a described embodiment, a control module system includes a control circuit configured to control selective opening of a plurality of valves interconnected between a plurality of accumulators and multiple tools, all positioned within the well. Additionally, the control circuit communicates with a terminal at the earth's surface for transmitting instructions from the terminal to the control circuit, and for transmitting data from the control circuit to the terminal.

Abstract: An improved sub-sea Xmas tree consists of a wellhead connector, a cylindrical structural housing and a tree cap mounted on top of the housing. A dual bore sub-sea completion test tree is disposed in the housing and it has a main production bore with serial ball valves for controlling fluid flow in the production flow path of an annuus bore with a ball valve therein. The ball valves are independently and remotely actuatable by a remotely operated vehicle (ROV) override system to control communication through the Xmas tree and to comply with various regulatory standards. A cross-over valve is provided between the main bore and the annulus bore to allow fluid passage for well kill operations.

Abstract: A multi-gage blowout preventer test tool for testing different size ram and annular BOP's in one trip has an outer test tube assembly and an inner tube assembly connected in telescoping relation. The exterior of the outer tube has a plurality of pipe gage diameters corresponding to different drill pipe sizes. A top sub at the top end of the outer tube assembly connects to the drill string and contains an upper seal assembly and stinger. The bottom end of the inner tube assembly is secured to a bottom sub and the bottom end of the outer tube assembly is releasably connected to the bottom sub in the collapsed position. The bottom sub is connected to a test plug and tail pipe assembly and the tool is lowered through the riser pipe and BOP stack to set the test plug in the wellhead.

Abstract: A subsea test tree and associated methods of servicing a well provide enhanced safety in testing operations. In a described embodiment, a subsea test tree includes a latch head assembly, a valve assembly, and a ramlock assembly interconnected between the latch head assembly and the valve assembly. The valve assembly includes two safety valves, one of which is operable by displacing a piston within the latch head assembly. The other safety valve is operable by applying fluid pressure to a line connected to the latch head assembly.

Abstract: A test tool having a body, a mandrel, a ball valve with an actuating mechanism and a bore is lowered on a string of drill pipe and landed in a wellhead housing. A retainer ring with internal threads is carried by the mandrel and engages threads on the body. The retainer ring has a slot which is engaged by a tab on the mandrel, causing the retainer ring and the mandrel to rotate together. The ball valve engages a drive plate which couples with a clutch so that the drive plate may rotate relative to the clutch. A rocker arm engages the drive plate and the mandrel to open and close the ball valve in response to rotation of the mandrel. The test tool is lowered through a riser into a wellhead on pipe below a blowout preventer. The blowout preventer closes around the pipe to form a seal and fluid is pumped down a line to test the blowout preventer. After this test, rotation of the mandrel closes the ball valve automatically.

Abstract: A permanently installed, remotely monitored and controlled transient pressure test system is provided. This system utilizes shut-in/choke valves, pressure sensors and flow meters which are permanently associated with the completion string to perform transient pressure tests in single and multiple zone production and injection wells. The present invention permits full bore testing which thereby eliminates undesirable wellbore storage effects. The present invention further allows for pressure testing limited only to a selected zone (or zones) in a well without expensive well intervention and without halting production from, or injection into, other zones in the well. The permanently located pressure test system of this invention also allows for real-time, downhole nodal sensitivity and control. This pressure test system may be permanently deployed either in production wells or injection wells.

Abstract: A downhole tool apparatus (34) including a housing (42) adapted to be connected in a pipe string (30), the housing (42) having a generally cylindrical bore (44) defined therein, an operating assembly (112) disposed within the cylindrical bore (44) of the housing (42) having open and closed positions and a mandrel (142) slidably received in the cylindrical bore (44) of the housing (42) and adapted to be selectively telescoped between first and second axial positions relative to the housing (42) to manipulate the operating assembly (112) and selectively rotated between first and second circumferential positions relative to the housing (42) to selectively lock the mandrel (142) in an axial position relative to the housing (42).

Abstract: In an offshore oil installation, the closure device (40) of a subsurface test tree placed in the blowout preventer stack on the seabed is made in a modular manner. More precisely, the closure device comprises a plurality of lengths (54,56') suitable for being placed in arbitrary order between a top element (50) and a bottom element (52). This arrangement makes it possible to place the connector (46) between the total shutoff valves (26) and the partial shutoff valves (28) of the blowout preventer stack, and to place the valves (42,44) of the closure device (40) in a closure length (54) that is situated beneath the partial shutoff valves (28). The two total shutoff valves (26) can thus be actuated regardless of the type of blowout preventer stack that is used.

Abstract: A tubing test valve (34, 34a) is described for use with a drill string (20) for pressure testing tubulars and downhole equipment, particularly in a cased hole (12) which has a permanent packer (16) fitted. The valve (34) permits self-filling during running-in, but allows pressure testing when stationary in the well (1). The valve (34) also permits multiple entry of the string to, and retrieval from, permanent packers without committing the tool to the locked open position. This is achieved by providing an apertured ball valve (50, 50a) in the tool housing (42, 42a) which can be moved axially and rotated with the bore (70A, 71A) of the housing (42, 42a). The ball valve has side orifices (54, 54a) and a top orifice (52a) which controls flow through the valve (34, 34a). In one embodiment the ball element (50) is suspended by coil spring (64) above the lower valve seat (56) during running-in and is closed for pressure testing by pressuring with fluid from above.

Abstract: The present invention provides an apparatus and method for testing a subterranean formation. The inventive apparatus comprises an internal-external differential pressure operated circulation tool, an external pressure operated drill stem testing tool, and an external pressure operated formation testing tool. The drill stem testing tool is positioned in the inventive apparatus beneath the circulation tool and the formation testing tool is positioned in the apparatus beneath the drill stem testing tool. In the method of the present invention, a testing string comprising the inventive apparatus is run into a well bore.

Abstract: Sondes provided with magnets are used in wells fitted with a metallic casing. The sondes are pressed at the surface against the inner wall of the casing and taken down towards the bottom by means of a stiff driving element such as a tubing provided with thrust driving means for the longitudinal drive and lateral extensions for the lateral positioning of the sonde, or using pulling slings, etc. The wall of the sonde pressed against the casing can have the same bending radius as the casing in order to improve the coupling. The sonde can be associated with an electronic data acquisition and transmission box fastened to the tubing. Before any intervention is performed, the tubing is moved sufficiently in order to suppress any mechanical coupling with the sonde. After it has been used, the sonde can be displaced towards another point of measurement or taken up to the surface by moving the tubing.

Abstract: A subsea test tree having a spherical ball valve member is modified to accommodate cutting of a string of coiled tubing extending through the ball valve member. This is accomplished by providing an eccentric recess in an inner bore of the subsea test tree, with the eccentric recess being positioned to receive a lower portion of the coiled tubing string as the coiled tubing string is cut by the ball valve member. This reduces the plastic deformation of the lower portion of the coiled tubing string as the coiled tubing string is cut by the closing ball valve member, and thus reduces the closing force necessary to reliably cut a coiled tubing string when the spherical ball valve member of the subsea test tree is closed in an emergency situation.

Abstract: A differential pressure actuating system for downhole tools provides endless operation by the use of the differential pressure between two isolated zones of a well as a power source for the tool. That differential pressure is applied across a power transfer element to operate the downhole tool.

Abstract: Fluid influx in a borehole is determined by examining and monitoring the computed transfer function in the signal channel defined by the annulus between the borehole and a drillstring in the borehole.

Abstract: A pressure measuring device will measure pressure in a subsea tubular member. The device includes a stationary unit mounted to the exterior of the tubular member and a movable unit that will be lowered into position next to the stationary unit whenever pressure is to be monitored. The stationary unit has a strain gage which will monitor pressure by measuring strain in the tubular member. The stationary unit has a light emitter which will emit pulses corresponding to pressure measured. The stationary unit has a photocell which will receive a light beam from the movable unit. The light beam and photocell provide power for the stationary unit. The movable unit has a receiver which receives any light pulses from the light emitter and correlates them to a pressure measurement.

Abstract: A method is provided for detecting outflow of fluid from an offshore wellbore to a surrounding earth formation or inflow of fluid from the formation of the wellbore. The wellbore is in fluid communication with a conduit extending between the wellbore and an offshore structure floating above the wellbore, which wellbore and conduit are at least partly filled with a body of fluid. Liquid is injected into the body of fluid at a first predetermined flowrate, and liquid is discharged from the body of fluid at a second predetermined flowrate. A variation of the content of the body of fluid is then determined.

Abstract: A downhole tool includes a hydraulic power supply containing a volume of compressed gas. The hydraulic power supply can be recharged while the tool is located downhole in the well by recompressing the gas in the power supply chamber.

Abstract: A differential pressure actuating system for downhole tools provides endless operation by the use of the differential pressure between two isolated zones of a well as a power source for the tool. That differential pressure is applied across a power transfer element to operate the downhole tool.

Abstract: There is disclosed a system for controlling the operation of a ram of a subsea blowout preventer connected to a piston shiftable between alternate positions within a cylinder. The system includes valve apparatus for so shifting the piston which includes an outlet connected to the cylinder, a first passageway through which hydraulic fluid may be supplied to the outlet, a second passageway through which hydraulic fluid may be vented from the outlet, and a valve member movable between positions alternately connecting the outlet with the first and second passageways, respectively, so as to selectively supply hydraulic fluid to or vent hydraulic fluid from the cylinder.

Abstract: Methods for the early detection of gas kicks in marine risers (10) include monitoring a downhole absolute pressure and a downhole differential pressure of a riser section (11) positioned just above the blowout preventer (18). The absolute pressure is used to calculate an average density of mud or mud/gas mixture in the entire riser (10). The differential pressure across the riser section (11) is used to calculate an average density of mud or mud/gas mixture in riser section (11). An unfavorable comparison between the calculated density for the mud or mud/gas mixture in the riser section (11) and the calculated density for the mud or mud/gas mixture in the entire riser (10) is used to detect the onset of a gas kick and to alert the operator. Alternatively, the measured differential pressure across the riser section (11) can be compared with an expected downhole differential pressure. Unfavorable comparisons of the measured and expected differential pressures indicate the onset of a gas kick.

Abstract: An apparatus for detecting oil and other lighter-than-water contaminants in an effluent stream in a sewage system. The apparatus includes a disposable detector which floats in the effluent stream and detects oil and other contaminants having a specific gravity lighter than the water by absorbing the oil and such contaminants in an oleophilic material, permitting the oil and other contaminants to rise and collect in a collection tube. The acidity of pH of the effluent being monitored is determined by routing a portion of the effluent stream across a litmus paper.

Abstract: A method for servicing an offshore well having a subsea blowout preventer. A sealing nipple having a wireline extending therethrough and connected to a servicing tool is lowered into the well and sealed by sealing rams of the blowout preventer. After the sealing rams are closed about the sealing nipple, the well can be pressurized through a fluid line extending to a work area. The method is particularly useful for pressurizing a cased well to eliminate any microannulus between the well casing and cement surrounding the casing prior to running a cement evaluation logging tool through the well.

Abstract: Apparatus and methods are provided for testing a blow-out preventor system of a well, which blow-out preventor system is designed to close upon both a smaller drill pipe string and a larger drill pipe string. The apparatus includes a first elongated cylindrical testing mandrel having an outside diameter substantially equal to an outside diameter of the smaller drill pipe string, and a second elongated cylindrical testing mandrel having an outside diameter substantially equal to an outside diameter of the larger drill pipe string. The first testing mandrel is telescopingly received within the second testing mandrel.

Abstract: A hydraulic control system for controlling a retainer valve in an underwater well test system. The control system is contained in a housing in the test string above the retainer valve. The control system and valve are operated by a surface control manifold via control conduits extending between the manifold and control system housing. The system provides opening and closing and very quick closure of the retainer valve by eliminating the requirement for closing pressure to be conducted through a long conduit from surface and by utilizing well pressure to close the valve and lock the valve closed. One embodiment of the control system requires a pressure pulse from surface to start quick retainer valve closure. Another embodiment of the control system monitors control conduits for loss of pressure while the retainer valve is open and automatically closes the valve on loss of control pressure.

Abstract: An improved method and apparatus for operating or setting equipment within a subsea marine wellhead from the surface having an indicating signal provided at the surface of the successful completion of such operation. The steps of the method include the lowering of a well component and the detecting and transmitting equipment on a running string from the surface; detecting the successful completion of the subsea operation, and transmitting to the surface of a signal signifying that the operations within the subsea well head have been successfully completed.

Abstract: The present invention comprises a rapid cycle tester valve operable in response to annulus pressure. The tester valve includes a valve ball rotatable between open and closed positions through an operating mechanism which includes a ball and slot ratchet mechanism for selectively transmitting operating movement from a pressure responsive slidable valve housing through a mandrel assembly. The valve housing employs back to back check valves disposed in a longitudinal valve passage to create pressure differentials to move the valve housing in response to annulus pressure increases and decreases.

Abstract: A subsea test assembly securable in a subsea blowout preventer stack is used in methods for performing wellbore tests and for disconnecting a tubular string from a subsea wellhead. The test valve assembly includes an upper subassembly releasably latched to a lower subassembly. Dog members are latched and unlatched in a corkscrew manner requiring only a slight rotation, and are held in the locked position by an axially movable sleeve. Nominal rotation of the latch within the upper subassembly is required to latch and unlatch the dogs, and a relatively short stroke of the movable sleeve locks and unlocks the dog members. The latch may be hydraulically or mechanically deactivated. The valving of the test assembly preferably comprises a ball member having both a metallic and elastomeric seal for sealing the passageway through the assembly. The elastomeric seal is carried by the ball and engages a metallic sleeve axially movable below the ball for sealing engagement against the ball.

Abstract: A multi-mode testing tool operable as a drill pipe tester, formation tester, nitrogen displacement valve or circulation valve. Tool mode is changed responsive to pressure cycling in the well bore. A ball valve in the tool bore may also be operated by pressure cycling when the tool is in its formation tester mode. Also disclosed is a pressure responsive double-acting piston power mechanism, and a ball and slot ratchet assembly.

Abstract: Disclosed is a safety system for well testing, utilizing a new and novel bleedoff tool in the subsea test tree handling string, which provides rapid pressure reduction in the handling string and assures mechanical disconnect of the subsea test tree if the test tree cannot be disconnected hydraulically. The bleedoff tool is operated and opened to bleed pressure from the handling string by applying a predetermined torque. This tool may be extended by pull to transmit higher than opening torque and will transmit torque after opening. The bleedoff tool contains an internal valve, which closes when the bleedoff tool is opened, and retains fluids in the handling string. The bleedoff tool operating torque values are not changed by high internal pressures or great axial tension or compressive loads on the tool.

Abstract: In accordance with illustrative embodiments of the present invention, a new and improved subsea test tree includes a hydraulically operable control unit and shut-in valve unit that are releasably latched together. The control unit includes an integral retainer valve system at the upper end thereof. The main shut-in valve, which is a ball valve, is a fail-close device under the influence of a spring and nitrogen pressure. Additional assistance in closing the valve may be provided if needed by hydraulic pressure applied to a surface control line. Internal pressure may be vented prior to unlatching the control unit in case of an emergency.

Abstract: Pressure operated circulation valve and method for using the same. A cylindrical housing has an open longitudinal passageway therethrough and a circulation port disposed through a wall thereof. A valve mandrel is slidably received in the housing and is moveable between a position in which fluid may be circulated only between the passageway and the exterior of the housing, a position in which fluid may be circulated only between the exterior of the housing and the passageway, and a position in which fluid may not be circulated in either direction. An annular piston is operatively connected to the valve mandrel and has a first side exposed to pressure exterior of the housing and a second side expose to pressure interior of the housing to permit movement of the valve mandrel to its various positions by application of pressure to the interior and exterior of the housing.

Abstract: An electro/hydraulic system for controlling remotely located valves or other types of hydraulically powered equipment. The electrical system uses multiple microprocessors to send, validate, and execute commands. Microprocessors at the central control station constantly communicate with and monitor similar microprocessors at remote locations. The validation of commands increases safety and reliability of the present invention as compared to direct electrical control systems. The electrical components of the present invention greatly decrease the lapse time between initiating a command at the central location and equipment response at the remote location. The system also monitors and displays temperature, pressure, and valve position.

Abstract: A multi-mode testing tool operable as a drill pipe tester, formation tester, nitrogen displacement valve or circulation valve. Tool mode is changed responsive to pressure cycling in the well bore. A ball valve in the tool bore may also be operated by pressure cycling when the tool is in its formation tester mode. Also disclosed is a pressure responsive double-acting piston power mechanism, and a ball and slot ratchet assembly.

Abstract: A subsurface test tree so compact in its vertical dimension that the entire tree can be positioned below the blind rams in a blowout preventer stack. When the stinger is removed the remaining valve section of the tree will be below the blind rams in any conventional blowout preventer stack.The valve operators are split, one carried by the stinger and one carried in the valve housing with the arrangement of operator and valve in the housing providing an extremely small vertical dimension. A dome charge is effective on a piston to drive a ball valve to closed position to cut a line extending through the ball valve and to provide sequential operation between the ball valve on bottom and the valve thereabove which may be a flapper valve so that the lower valve closes and the line is cut before the upper valve closes.In one form the invention includes a subsurface safety valve below the test tree operated by one of control or balance pressure fluid.

Abstract: For use in providing control of a pulsed neutron generator tube and its associated power supplies, the preferred and illustrated embodiment of the control circuit senses the operative condition of the pulsed neutron generator tube by observing external insulating gas pressure of the sealed tube to monitor for a loss of pressure, target current magnitude, pulsing of the ion source, current flow for the replenisher and operation of the high voltage power supply. This system functions as an interlock, thereby enabling operation of the tube if nominal operative conditions are achieved. Conversely, the absence of nominal operative conditions switches the equipment off to protect the tube from damage resulting from malfunction.

Abstract: A motion compensator for disposition between an offshore support and an offshore well string or the like movable with respect to the support comprises first and second compensator bodies interconnected with the support and the well string such that relative movement between the support and well string causes relative movement between the compensator bodies. The compensator bodies are further interconnected with each other for relative movement in generally vertical directional modes. A compressible fluid or the like is associated with the compensator bodies for resiliently resisting relative movement therebetween in a first directional mode. A position indicator associated with the compensator bodies comprises a flexible vessel having one end connected to one of the compensator bodies and the other end connected to the other compensator body generally below the one end.