Abstract: A chamber in a well is connected to two externally separate tubing strings to unload liquid which is applying backpressure against a formation so that the production of fluid from the formation is obstructed. Volumes of the liquid are intermittently collected in the chamber and lifted out of the well through one of the tubing strings in response to high pressure gas injected solely into the chamber through the other tubing string.

Abstract: An automatic timed shut-in valve for pressure transient testing of a well and the like includes a body member adapted for connection to a locking device for locating the valve at a predetermined point in a tubing string. The valve includes a clock timer and an actuator which is operable to close the valve at a predetermined time after insertion of the valve in the tubing string. Various operations may be carried out including automatic times shut-in of a well or pressure transient testing by recording at least one of pressure and temperature in the well in timed relationship to actuation of the valve so that wellbore and formation conditions can be measured upon shut-in of the well.

Abstract: A system for placing instrumentation within a hole enables a wide variety of instruments to be placed in the hole with enhanced measurement resolution and minimum risk of becoming lodged in the hole by partial collapse of the hole wall. A flexible tubular member is pressurized and averted from a canister into the hole, turning inside out as it extends into the hole. The application of pressure urges the tubular member against the hole wall in the manner of a hole liner or packer. A wide variety of instruments can be attached to the membrane and urged against the hole wall for measurement purposes. Typical measurements include temperature, pore fluid extraction and injection, in situ sensing with fiber optics, pore fluid pressure, and the like.

Abstract: A groundwater pollutant recovery system using the cone of depression approach, in which a sensing probe having liquid level sensors responsive to both water and pollutant levels and having attached to it the pollutant intake is deployed in a recovery well above the submerged water and pollutant pumps. The pollutant intake on the sensing probe is attached to the pollutant pump by an extendable hose so that the sensing probe may be raised and lowered in response to changing hydraulic conditions in the well, without the necessity of changing the water or pollutant pump positions. The recovery sequence is controlled by a microprocessor under the control of a program responsive to the liquid levels indicated by the sensors in the sensing probe.

Abstract: A tubing end locator is disclosed having a mandrel and a collet carried by the mandrel. The collet has an annular base and a plurality of fingers having one end attached to the base and a free end extending from the base along the mandrel in parallel, spaced relationship. A beveled lug is carried by the free end of each finger. A flange on the mandrel has a diameter such that the lugs on the fingers will extend beyond the inside diameter of the tubing when the free ends of the fingers are in engagement with the flange. Means hold the fingers in engagement with the flange and resist the re-entry of the fingers into the tubing after the tubing end locator has passed out of the tubing until a substantial upward force has been exerted on the mandrel thereby giving a surface indication that the tool had engaged the lower end of the tubing.

Abstract: A well fluid sampling apparatus provides a time delay after actuation of the tool and before a sample is taken. The tool is operated by well pressure acting on a piston. The piston is initially hydraulically blocked so that it cannot move. The time delay is provided after the piston begins moving. Additional time delay devices can optionally be included.

Abstract: A method and apparatus for locating and determining the quality of a downhole wet cement abandonment plug positioned in an open bore hole. The quality of the plug is detetmined by retrieving a sample of the wet cement mixture to the surface by remotely operating a fluid sampler included as one component in a logging tool. The sample permits the determination of the purity and quality of a downhole wet cement plug, providing valuable information for assessing whether the plug will set properly. Thus the method and apparatus greatly reduces the risk of plug failure due to an inferior cement mixture resulting from the intrusion of contaminants in a wet cement plug.

Abstract: A running tool and method for the use thereof in locating apparatus in a well bore includes an elongated hollow tool body and outer sleeve encircling the body; a mandrel disposed within the body and sleeve and carrying a collet on the lower end thereof which, in the running position of the tool, is enclosed within the sleeve; and a sealed chamber having a substantially incompressible fluid therein which is metered through a flange located on a tool mandrel to control the time required to move the mandrel between the running and release positions, thus controlling the force and time required for actuation of the tool to avoid inadvertent release of the well apparatus being lowered into the well bore.

Abstract: A method and apparatus are provided for locating a solvent injection apparatus within a natural gas wellbore to reduce the deposition of hydrocarbonaceous solids which are at least partially soluble in the solvent.

Abstract: A gas and oil well controller includes a microcomputer control circuit which can control well production by monitoring well pressure levels, by time limitations, or any combination of the two. The controller includes a casing pressure sensor, a tubing pressure sensor, and a line pressure sensor for sensing pressure in the sales line, and a plunger position sensor for sensing the position of a plunger adjacent a top position in the well tubing. The microcomputer control circuit is in operative communication with the production valve, the casing pressure sensor, tubing pressure sensor, the line pressure sensor and the plunger sensor to open and close the production valve for gas flow to the sales line when the casing, tubing, and line pressures bear a predetermined relationship to preselected pressure limits or when the plunger is sensed by the plunger sensor. The controller includes a device for preselecting limit delays to suspend valve operations during pressure surges to avoid premature opening or closing.

Abstract: A tracer deployment tool for discharging a quantity of radioactive or other toxic tracer material into a wellbore for distribution into an earth formation with an injection fluid includes a first piston held in a predetermined position by shear pins and a member supporting a rupturable vial of tracer material. The member connected to the piston is formed as a generally cylindrical cage through which a knife member extends and responds to movement of the cage to rupture the vial. Movement of the piston uncovers passages which permit through-flow of liquid through the vial retaining cage to flush the tracer material thoroughly from the tool. An elongated actuating rod is connectable to a packer setting mechanism or the like for effecting operation of the tool. An alternate embodiment includes two pistons which define the tracer holding chamber.

Abstract: A core drilling tool for drilling rock in underground soil formations which includes an outside pipe and an inside pipe therein that can be conveyed separately to the surface. The inside pipe includes a core-receiving receptacle at its lower end, and at its upper end is provided with a measurement unit for on-site acquisition, processing and storage of data, such as borehole, core and/or drilling process parameters.

Abstract: A groundwater pollutant recovery system using the cone of depression approach, in which a sensing probe having liquid level sensors responsive to both water and pollutant levels and having attached to it the pollutant intake is deployed in a recovery well above the submerged water and pollutant pumps. The pollutant intake on the sensing probe is attached to the pollutant pump by an extendable hose so that the sensing probe may be raised and lowered in response to changing hydraulic conditions in the well without the necessity of changing the water or pollutant pump positions. The recovery sequence is controlled by a microprocessor under the control of a program responsive to the liquid levels indicated by the sensors in the sensing probe.

Abstract: In a preferred embodiment, an eletronic temperature gauge is carried into a well bore within a pressure-sealed housing which can free fall through a drill string to impact upon a drill bit connected at the bottom of the drill string. A shock absorber is connected at the bottom of the housing to absorb the shock upon impact of the apparatus on the drill bit. The shock absorber has a relatively linearized shock absorbing response in the preferred embodiment. Additional structural features provide further cushioning of the gauge during transit and upon impact.

Abstract: A programmable system for controlling the operation of a plunger completion oil or gas production well to optimize production from the well. The controller operates one or more motor valves controlling the well in accordance with programmable values of off-time, on-time and exhaust-time. The controller monitors whether or not a plunger arrival signal is received on each cycle of intermitting the well and changes either the off-time or the exhaust-time for the next cycle in response thereto. In oil well mode, the off-time is decreased slightly for each cycle following a cycle in which plunger arrival occurred and increased slightly for each cycle following one in which it did not. In gas well mode, the exhaust-time is increased slightly for each cycle following a cycle in which plunger arrival occurred before on-time expired and decreased slightly for each cycle following one in which it did not.

Abstract: A controller for gas-oil well installations which is microprocessor driven and compiles a datalog which is accessible locally for operator use. Customized microprocessor control for a given well installation is available on a practical basis by resort to the employment of a program approach utilizing bit-string patterns selected from a relatively large sequence of predefined well installation operational parameters or variables which have been identified. The masking and pattern recognition approach permits the handling of relatively large amounts of data and greatly simplifies the customization of well programming. This programming facility permits remote alteration of programs either by telephonic communication or by networking of a plurality of controllers within a given oil field. The programming feature is complemented by the utilization of a variable opening control over a motor valve.

Abstract: A method and apparatus for treating subterranean wells includes a tool supported on a one-piece support tube which operates to raise and lower the tool in the well to a position where well treatment is required. The tool provides inflatable packers and a selector valve operable in a first position to inflate or deflate the packers, in a second position to circulate fluid to spot treatment fluid at the tool, and a third position for injecting treatment fluid into the strata isolated from the remainder of the well by the packers. The tool provides a J-lock system and a time delay dashpot which cooperate to permit an operator at the well head to selectively operate the valve between the three positions solely by adjusting the weight on the support tube at the well head.

Abstract: A delayed opening fluid sampling tool comprises a body having three chambers and a port defined therein. The tool also comprises a metering device which is disposed in the body between two of the chambers, one of which chambers is for holding a metering fluid and the other of which is for receiving fluid which is transferred through the metering device. The tool further comprises a valve which is disposed in the body between the port and the remaining chamber, which remaining chamber is for receiving a well fluid sample. The valve is moved relative to the body in response to pressure acting on the valve through the port. Only after a predetermined time delay after the pressure begins moving the valve is the valve positioned to communicate the port with the sample-receiving chamber.

Abstract: Wellhead apparatus as set forth for installation on a producing gas well which has a certain measure of condensate therein. The device includes an alignment tube which is precisely constructed for easy transition from the tubing string. That connects to a master valve which connects to a tee thereabove. A lateral flow line connected with a gas valve regulates gas produced from the well. The master valve is just below the tee, and the tee extends upwardly into a lubricator extension tube. The two are connected together by a lubricator extension union sub which utilizes a lock nut engaging a pair of matching shoulders. A method of timed production is also disclosed.

Abstract: A multi-valve well testing system adapted to be disposed downhole in a borehole, includes a plurality of valves and a plurality of well tool control systems connected, respectively, to the plurality of valves and further includes an automatic control mode feature. The well testing system includes a controller board which comprises a microprocessor and a read only memory (ROM). The ROM has encoded therein a set of microcode which, when executed by the microprocessor, causes the various plurality of valves in the well testing system to be opened and closed automatically, without intervention from the operator at the well surface. A kickoff stimulus is required in order to begin execution of the microcode by the microprocessor. This kickoff stimulus could include a sensing, by a pressure transducer, of a predetermined bottom hole pressure, or a sensing, by a strain gauge, of a predetermined set down weight of the well testing system.

Abstract: A method of controlling the recovery of landfill gas from a sanitary landfill and apparatus for performing the method. Landfill gas, which mainly consists of methane and carbon dioxide, is formed by anaerobic decomposition of the organic content of the refuse. This process develops a very small amount of heat. If more gas is drawn from the sanitary landfill than is formed by the anaerobic decomposition, air is drawn into the landfill. The decomposition thereby becomes aerobic, developing large quantities of heat and increasing the content of carbon dioxide and nitrogen in the gas. According to the disclosed method, the temperature of the gas from each gas well is measured, thereby providing information for controlling the flow of gas from the corresponding wells. The apparatus disclosed by the invention comprises a control chamber connected to one or more gas wells on the one hand and to a gas furnace over a gas fan on the other hand.

Abstract: An electrically operated firing piston is provided for effecting the firing of a perforating gun in a subterranean well. The electrical firing system is disposed within a hollow housing which is detachably secured to the gun and is subject to the fluid pressures surrounding the perforating gun. The electrical firing system is armed through the application of a fluid pressure to the exterior of the housing which is in excess of the well hydrostatic pressure, thereby preventing premature firing of the perforating gun before insertion at its desired position in the well. The generation of an electrical firing pulse is controlled by a microprocessor which is preset to be responsive only to a selected value of fluid pressure surrounding the control housing. Thus, the pressure surrounding the perforating gun may be reduced to a selected under-balanced condition before the firing of the gun can be effected.

Abstract: An oil well pump control for regulating operation of a pumping apparatus such as a pumping jack through a timing system which is actuated by the fluid pulses or surges that result from the pumping action of the pump.

Abstract: In accordance with illustrative embodiments disclosed herein, a formation testing tool suspended in a well on a pipe string includes a valve actuator control system which responds to a command signal having a certain signature. The command signal is applied at the surface to the well annulus, and includes a series of two or more low level pressure pulses which are detected at the downhole tool, each pressure pulse having, for example, a certain peak value which lasts for a certain time. On detection of the command signal, a control system within the testing tool permits selective application of hydrostatic pressure which forces the valve actuator to shift from one position to another, thereby to open or close an associated valve element.

Abstract: A method and apparatus for treating oil and gas wells by automatically pre-flushing the well casing annulus with production fluid, pumping treatment chemicals into a rapidly flowing production fluid line for uniform mixing and introduction into the casing annulus, and post-flushing with production fluid.

Abstract: A method for continuous analysis of mixtures for determining selective properties of components in the mixture flowing along a flow path includes the steps of, firstly, directly measuring and/or calculating the pressure, temperature, density and mass flow rate of the mixture at a first point upstream of a characteristic change zone in the flow path. A change in the characteristics of the mixture flow is caused in the characteristic change zone, and thereafter, the pressure, temperature, density and mass flow rate are measured directly and/or calculated at a second point downstream of a characteristic change zone. Selected properties of the mixture are determined on the basis of the information collected together with known parameters using algorithms.

Abstract: A mechanism for accurately positioning a well tool in axially concentric relationship to a well conduit comprises a housing having a plurality of peripherally spaced vertically extending slots therein. A stabilizer linkage is mounted in each slot, with one end of the linkage being pivotally secured in the slot and the other end free to move in an axial direction. Axially spaced anti-friction elements are carried on the linkage and are movable radially into engagement with the casing wall by axial movement of the other end of the stabilizer linkage. The other end of the stabilizer linkage is pivotally secured to a sleeve which is sealably and slidably mounted within the housing and defines a trapped fluid chamber which acts as a dashpot to delay radial expansion movement of the stabilizer linkage.

Abstract: In accordance with illustrative embodiments disclosed herein, a formation testing tool suspended in a well on a pipe string includes a valve actuator control system which responds to a command signal having a certain signature. The command signal is applied at the surface to the well annulus, and includes a series of two or more low level pressure pulses which are detected at the downhole tool, each pressure pulse having, for example, a certain peak value which lasts for a certain time. On detection of the command signal, a control system within the testing tool permits selective application of hydrostatic pressure which forces the valve actuator to shift from one position to another, thereby to open or close an associated valve element.

Abstract: A centralizing device for use down-well in maintaining a sensor or other operational tool in a location accurately centralized on the axis of the bore-hole irrespective of the angular orientation of the device and associated tool at any given location. The device includes an elongate member carrying at angularly spaced locations three two pairs of opposed, two-arm linkages, each arm of each linkage being pivoted to the other arm of that linkage at a location spaced from the elongate member when in an extended position and being pivoted at the other end of the arm to a respective one of two slide blocks each of which is movable axially of the elongate member.

Abstract: The invention provides an apparatus for limiting tension produced in a tubular string extending from a packer set in a subterranean well to the well surface. Such apparatus comprises a receptacle secured to the packer and defining an elongated seal bore, and a mandrel telescopically and sealably related to the seal bore, the mandrel being connected to the bottom end of the tubing string. In one embodiment, a collet, incorporated in the receptacle for cooperating with an abutment formed on the mandrel, thereby securing the mandrel and the receptacle in a telescopically contracted position until sufficient tensile force is exerted on the mandrel to cause the collet arms to be expanded by the abutment to permit upward movement of the mandrel relative to the receptacle.

Abstract: The present invention in its preferred embodiment comprises a combination anchor including a first tubular member having a circular shoulder formed around the perimeter of its bore. Adapted to be releasably inserted inside the tubular member is a bullplug comprising a cylindrical shaped plug member with a rounded bottom section and a seat ring adapted to be threadedly connected to the top section of the plug member. Adapted to be connected to the seat ring and plug member by means of cooperating threads is a mandrel. A conical member having a plurality of compressible legs depending therefrom is insertable over the mandrel and secured thereon by a cap member which fits over the conical member and may be attached thereto by means of cooperating threads. Threadedly connected to the top of the cap and extending upwardly into the bore of the tubing string is a rod, which is more commonly known in the trade as a rod sub. At the end of this rod sub is the male counterpart of a locking device known as a J-latch pin.

Abstract: New controlled retracting gasifying agent injection point process for UCG sites.The process consists of a retraction of the gasifying agent injection point achieved by gradually plugging the tubing ends either by pneumatic injection of inert granulated material with a thermosetting binder, or by closing valves set at regular intervals inside the tubings.

Abstract: The high pressure gauge carrier of the present invention uses an outer gauge carrier housing having disposed therein a pressure-tight inner housing carrying a temperature gauge in the interior thereof. The inner housing is substantially filled with a compressible liquid, and the pressure tight connections of the inner housing incorporated metal to metal seals in order to eliminate the failure of elastomeric seals at the elevated temperatures encountered by the gauge carrier.

Abstract: A fluid sampling apparatus is disclosed for withdrawing samples of groundwater or other fluids from a well or other monitoring site. The apparatus preferably includes pump means, conduit means and a wellhead assembly that are substantially permanently installed at such well or monitoring site and are thereby dedicated thereto in order to avoid or minimize cross-contamination of samples from site to site. The apparatus preferably also includes a removable and portable controller means adapted for easy and convenient transportation and connection to such dedicated fluid sampling components at various wells or monitoring sites. A recovery, collection and control system for cleanup of leachate or other liquid material or contaminated groundwater from a landsite is also disclosed.

Abstract: The subsurface position of a blowing well with respect to an adjacent relief well is determined by detecting at a plurality of axially and tangentially spaced locations in the relief well acoustic waves emanating from a subsurface location of the blowing well. The distance between the wells is calculated on the basis of the difference in times of arrival of the waves at said axially spaced locations. The radial direction of the blowing well relative to the relief well is determined by measuring the acoustic intensity resulting from the waves at each of said tangentially spaced locations.

Abstract: A method of registering perforating guns in a tubing conveyed perforating assembly as set forth. On a tubing string, a TCP assembly is lowered in a cased well. In the tubing string, a logging cable supported radioactive logging tool is then moved along the well to controllably locate the formation of interest. After the depth of this formation is known, the tubing string is moved to reposition the TCP assembly in registry with the formation of interest. The logging tool is retrieved only partially and is then lowered to operative contact with the TCP assembly to provide a signal path for operation of a firing mechanism to fire the shaped charges to form perforations into the formation.

Abstract: A fully programmable system for controlling the operation of one or more gas or oil production wells by controlling the intermittent operation of the wells in response to either programmed information or monitored and measured criteria related to the wells themselves. The system includes battery powered solid state circuitry comprising a keyboard, a programmable memory, a microprocessor, control circuitry, means for inputting measured parameters from a plurality of transducers and a liquid crystal display system for displaying information contained within the memory, or one of the measured parameters. In one embodiment, the system monitors pressure, flow, and other parameters of a plurality of wells drawing petroleum products from a common reservoir to control the intermittent operation of either gas injection to the well, outflow of fluids from the well, or shutting in of the well to maximize the overall output of the entire array of wells drawing from the common reservoir.

Abstract: Methods and apparatus for the recovery of petroleum origin hydrocarbons and other liquids from underground at sites of refineries, oil, gasoline and other liquid storage and distributing facilities, tie creasoting plants, and the like. Pursuant to the invention, for petroleum origin hydrocarbon recovery, separate liquid handling devices, each in the nature of a vessel or canister and having liquid trapping and ejecting facilities that are free of mechanical pumping action, are employed for raising the ground water and liquid hydrocarbons that accumulate on the ground water table, respectively, through which the well or wells extend, and under the static pressure of the compressed air.

Abstract: A caliper is mounted on two springs in a free-floating manner between interlockable upper and lower packers to be set in a well bore. The caliper has radially extendible arms which are extendible in response to independent forces exerted thereon as derived from the movement of a carriage driven by a single motor contained in the caliper tool. A clutch mechanism is used to lock the arms to precision measurement transducers only after the arms have been moved radially outwardly a sufficient distance. Other transducers for generating signals indicating the total movement of the arms and for indicating the forces exerted by the springs on the arms are included in the preferred embodiment.

Abstract: Hot liquid-containing water-swollen tar is produced from a tar sand by injecting steam into a well, which is at least initially open and substantially free of obstruction to vertical fluid flow throughout a long vertical interval from the bottom of the tar sand, by producing said liquid from the bottom of the tar sand and maintaining injection and production flow rates that keep the steam temperature above about 450.degree. F. at a pressure high enough to keep the produced liquid substantially free of steam and near to, but less than high enough to damage the reservoir.

Abstract: A downhole tool is actuated at chosen well depth by selection of a control element that melts at the chosen depth well temperature. In one form of tool, a fusible pin melts to release spring-loaded jaws which move against an expansion cone to anchor the tool in the well. In another form, a fusible receptacle cover melts to release a quantity of dense fluid under action of gravity. Suitable control elements are formed of bismuth, with lead and zinc.

Abstract: An echo ranging gun (10) is disclosed which is useable with high pressure gas wells having gas pressure exceeding 15,000 psi. The gun (10) is connected to the needle valve (30) typically encountered on a well having high pressure. The needle valve can have a diameter as small as approximately 1/8 inch. The gun (10) has a passage (38) which is exposed to the gas in the wellbore (14) and a volume chamber (46). A poppet valve (56) is movable between open and closed positions in the volume chamber by rotating a wing handle (88) connected to a head (78) within the volume chamber (46) which has a ramp (80) to contact the poppet valve (56) to move the valve to the closed position. A bleed valve (112) is used to bleed the wellbore gas from the volume chamber to create a predetermined pressure differential between the passage (38) and volume chamber (46). Further rotation of the wing handle (88) causes the poppet valve (56) to be released from the ramp at a down step (86).

Abstract: Corrosion inhibiting of well production tubing, such as for an oil or gas well, is provided in a simple and effective manner without interrupting well production. A portable skid has a chemical tank, water tank, pumps, conduits, and controls mounted on it, and is transported to the production well site. A mix of corrosion-inhibiting chemical and water is supplied from the tanks to an end conduit, and the end conduit is connected to an injection string, or an annulus associated with a side mandrel, of the production well. A computer control is provided for controlling the pumps, and other components, so that any desired amounts and proportions of a mix of chemical and water is continuously injected into the well to inhibit corrosion of the well production tubing string without interruption of production.

Abstract: A fully programmable system for controlling the operation of one or more gas or oil production wells by controlling the intermittent operation of the wells in response to either programmed information or monitored and measured criteria related to the wells themselves. The system includes battery powered solid state circuitry comprising a keyboard, a programmable memory, a microprocessor, control circuitry, means for inputting measured parameters from a plurality of transducers and a liquid crystal display system for displaying information contained within the memory, or one of the measured parameters. In one embodiment, the system monitors pressure, flow, and other parameters of a plurality of wells drawing petroleum products from a common reservoir to control the intermittent operation of either gas injection to the well, outflow of fluids from the well, or shutting in of the well to maximize the overall output of the entire array of wells drawing from the common reservoir.

Abstract: Methods and apparatus for the recovery of petroleum origin hydrocarbons from ground water tables at sites of refineries, oil and gasoline storage and distributing facilities, and the like. Pursuant to the invention, separate liquid handling devices, each in the nature of a vessel or canister and having liquid trapping and ejecting facilities that are free of mechanical pumping action, are employed for raising the ground water and liquid hydrocarbons that accumulate on the ground water table, respectively, through which the well or wells extend, and under the static pressure of the compressed air.

Abstract: A tool changes the electrical conductance across a nonconductive separation in a string of electrically conductive casing in a well located in the earth. The tool is for transmission of data up the well. The casing has at least one inwardly extending landing shoulder for the tool. The tool has a housing elongated between first and second ends. The housing has a first contact for electrical connection to the casing on one side of the nonconductive separation. The housing has a second contact spaced from the first contact for electrical connection to the casing on the other side of the nonconductive separation from the one side. The housing also has a nonconductive housing portion, substantially circular in cross-section, between the first and second contacts. An outwardly extending landing shoulder is provided on the housing for landing and for supporting the tool on the casing landing shoulder.

Abstract: A well test system for automatically testing a plurality of wells in an oilfield is disclosed. The system includes means for detecting leaking diverter valves. The system also includes means for purging a test separator as a function of the number of free water dumps and the number of emulsion oil dumps or for alternatively controlling the purging of the test vessel or separator as a function of time or alternatively as a function of the first to occur of a predetermined number of dumps being achieved or predetermined time having elapsed. The system also has means for determining leaking or stuck open dump valves in the water leg or emulsion oil line of the system.

Abstract: A method for operating a production well during an oxygen driven in-situ combustion oil recovery process comprising continuously injecting an inert gas such as nitrogen or carbon dioxide into the bottom of the production well at a predetermined low injection rate, preferably 0.1 to 2 MSCF/day, and continuously monitoring the oxygen concentration of the produced effluent gas and the bottomhole temperature of the production well. In the event that the oxygen content of the effluent gas increases to a value within the range of 5 to 20 volume percent or the bottomhole temperature of the production well increases to a value within the range of 200.degree. to 300.degree. F., the injection rate of the inert gas into the bottom of the production well is increased to a maximum rate until the oxygen concentration of the effluent gas and the bottomhole temperature are reduced to a safe level.

Abstract: A gravity system, the only moving parts of which are the valves, uses only the system pressures, and opening and closing of valves to feed treatment liquids to an oil well. The chemical treatment liquid is stored in a drum above a volume chamber. The volume chamber has five lines connected to it, each with a valve. A feed line with a feed valve connects the volume chamber to the treatment drum. A vent line with a vent valve vents the top part of the volume chamber to the atmosphere. A liquid pressure line with a pressure valve connects the flow line (connected to the oil well eduction tube) to the volume chamber. A flush line with a flush valve connects the bottom of the volume chamber to the well annulus. A gas line with a gas valve connects the volume chamber to the annulus. When the vent valve and feed valve are open and all other valves are closed, the volume chamber will fill with liquid by gravity from the chemicals within the treatment drum.

Abstract: Apparatus is disclosed for automatically operating a gas and oil producing well of the plunger lift type, including a comparator for comparing casing and tubing pressures, a device for opening the gas delivery valve when the difference between casing and tubing pressure is less than a selected minimum value, a device for closing the gas discharge valve when casing pressure falls below a selected casing bleed value, an arrival sensor switch for initially closing the fluid discharge valve when the plunger reaches the upper end of the tubing, and a device for reopening the fluid discharge valve at the end of a given downtime period in the event that the level of oil in the tubing produces a pressure difference greater than the given minimum differential value, and the casing pressure is greater than lift pressure. The gas discharge valve is closed if the pressure difference exceeds a selected maximum value, or if the casing pressure falls below a selected casing bleed value.