Showing papers on "Annulus (oil well) published in 1988"

System and method for communicating signals in a cased borehole having tubing

Abstract: A system and method are disclosed for wireless two-way communication in a cased borehole having tubing extending therethrough. A downhole communications subsystem is mounted on the tubing. The downhole subsystem includes a downhole antenna for coupling electromagnetic energy in a TEM mode to and/or from the annulus between the casing and the tubing. The downhole subsystem further includes a downhole transmitter/receiver coupled to the downhole antenna, for coupling signals to and/or from the antenna. An uphole communications subsystem is located at the earth's surface, and includes an uphole antenna for coupling electromagnetic energy in a TEM mode to and/or from the annulus, and an uphole receiver/transmitter coupled to the uphole antenna, for coupling the signals to and/or from the uphole antenna. In accordance with a feature of the invention, the annulus contains a substantially non-conductive fluid (such as diesel, crude oil, or air) in at least the region of the downhole antenna and above.

Subsea casing hanger suspension system

Abstract: A well casing suspension system comprising a casing hanger assembly with an expandable, multiple shoulder, split load ring that is radially expanded into supporting position in a mating groove in a wellhead housing by contact with a previously installed annulus packoff.

Vertical oil separator

Abstract: A vertical separator for separating crude oil into liquid and gas phases composed of an outer casing and two further sets of concentric tubing to enclose two annuli and a central passage, one annulus having an inlet to receive crude oil, the other annulus having an outlet for separated gas, each at the top of the separator. The central passage collects produced oil with a pump near its base and a pump drive pipe extending up it. The crude oil may flow down its annulus with a swirling motion which can be induced and assisted by a tangential inlet, and/or a cyclone at the top, and one or more helices in the annulus. The separator may be used for underwater wells and may extend partially or wholly into the sea bed with a protective cemented external casing around it.

Method for improving drill cuttings transport from a wellbore

Abstract: A borehole tool employs a drill string having a plurality of sections of drill pipe connected together for traversing a wellbore. Drilling fluid is circulated down the drill string and up the annulus between the drill string and the wellbore to transport entrained drill cuttings out of the wellbore. At least one section of double wall drill pipe with its outer wall perforated, is included in the drill string. Drilling fluid flow down the string into the section of double wall drill pipe is controlled to effect a desired degree of drilling fluid flow rate through the perforations in the outer wall of the double wall drill pipe section so as to provide a stirring action to the drill cuttings in the wellbore annulus and thereby improve the transport of entrained drill cuttings out of the wellbore in the circulating drilling fluid.

Weight-on-bit and torque measuring apparatus

Abstract: A drill string sub is disclosed for measuring the torque and axial compression in the drill string. The drill string sub includes an outer tubular housing (11) and an inner sleeve type apparatus mounted thereto for amplifying the strain the sensors measure. The sub further includes a section(40, 46, 49, 51, 55, 61, 63) for compensating for the axial stresses due to the local pressure differential between the drill string bore and the well bore annulus and for the thermal gradients occurring during operation. This section includes a balance tube (40) for isolating the internal bore pressure from acting on the strain amplifier (70) and for creating an upward axial force on the tubular housing (11) and strain amplifier (70) which is responsive to this pressure differential to counter the axial stresses mentioned above. The sensors (70) are encapsulated in oil to avoid theeffects of the corrosion and electrical shorting which are promoted by drilling fluids.

Cementing and rotating an upper well casing attached by swivel to a lower casing

Abstract: A method for completing a well to provide an uncemented lower casing and an upper cemented casing. The lower casing and upper casing are connected at a swivel joint so that only the upper casing is rotated while cementing. Inflatable packers and a plug are positioned at the lower casing to prevent entry of cement, while a port collar allows cement to flow into the annulus surrounding the upper casing. The invention is particularly useful when setting long lengths of casing and when completing highly deviated or horizontal wellbores. The method also allows an existing conventionally-completed well to be re-drilled and completed as a highly-deviated or horizontal well.

Hydraulic jar mechanism

Abstract: A hydraulic well jar mechanism capable of developing jarring force in an upwardly or downwardly direction or in both upward and downward directions for imparting jarring forces to stuck well pipe. Inner and outer tubular members cooperate to define an annulus therebetween, which annulus contains a volume of metering liquid such as oil. One or more metering valves are disposed within the annulus and establish metering of the metering liquid during a portion of the stroke of the well jar to thus retard movement thereof. After a certain metering movement has occurred, the operative metering valve will be clear of the metering surface and the jar mechanism will then have relatively free movment from the retarded position to the jarring position. Closing movement of the jar mechanism may be induced by a compression spring closure. The metering fluid within the annulus is balanced with well pressure while separated from well fluid by means of a floating piston disposed within the annulus and having sealed relation with both the inner and outer tubular members. The inner tubular member defines a central passage permitting insertion therethrough of well servicing tools, well fluid, etc.

Method of controlling fluid influxes in hydrocarbon wells

Abstract: The invention relates to a method of real time control of fluid influxes into an oil well from an underground formation during drilling. The injection pressure pi and return pressure pr and the flow rate Q of the drilling mud circulating in the well are measure. From the pressure and flow rate values, the value of the mass of gas Mg in the annulus is determined, and the changes in this value monitored in order to determine either a fresh gas entry into the annulus or a drilling mud loss into the formation being drilled. Application to the drilling of oil wells.

Apparatus and method for removal of accumulated liquids in hydrocarbon producing wells

Abstract: A method and apparatus are disclosed to detect periodic well loading by produced accumulated secondary fluids, and accordingly to remove the undesired secondary fluid from the tubing of a hydrocarbon producing well. The method according to the present invention employs a surface control system that controls the operation of the fluid removal cycle, and the production cycle of the hydrocarbon producing well. Periodically, the well is "shut-in" and upper and lower flow control valves, connected at a predetermined depth to the well tubing, are actuated to a closed position to form an accumulation chamber within the tubing. The closed flow control valves block off the fluid in the accumulation chamber formed in the lower portion of the tubing string, which contains the undesired accumulated secondary fluids. A supply line is used to inject pressurized gas from the surface of the well into the accumulation chamber to provide the necessary pressure to force the accumulated secondary fluids, trapped in the accumulation chamber, through a relief valve and into the annulus of the well casing thereby removing the undesired secondary fluids from the well tubing. The controller then stops the flow of the injected gas to the supply line to stop the removal cycle. The supply line pressure is relieved, and the pressure across the flow control valves are equalized. The flow control valves are then opened and the producing well is returned to production with reduced back pressure due to the removal of the undesired, accumulated secondary fluids from the tubing.

Tube coupling mechanism

Abstract: A coupling device for tubing for use in pressurized fluid systems and having a locking and unlocking actuator lever supported by an annulus in a flexible manner producing a mild bending movement of the annulus corresponding to pivotal movements of the lever.

Device for holding fishing lures

Abstract: A tubular casing having a circular-cylindrical inside surface contains and engages a hollow cylindrical elastomeric annulus under compression. The casing has vertical elongated openings which correspond to and align with slits through the annulus to accept the hook of a fishing lure. At least one casing-annulus device may be detachably fixed within a case.

Method and apparatus for cementing a production conduit within an underground arcuate bore

Abstract: An apparatus and method for drilling a bore hole (B) along an underground arcuate path (P) between two surface locations (O,E). The bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section 12 with a drill bit (14) thereon. Drilling fluid is supplied to the drill bit (14) during the drilling operation. Upon completion of the initial bore hole (B), the hole (B) may be enlarged by a reamer (40). Then, a production conduit (38) is connected to the reamer (40) for being pulled by the drill string (10) through the enlarged bore hole (D). Cement is supplied through the drill string (10) for discharge at the reamer (40) into the bore hole (D) adjacent the leading end of the production conduit (38) and fills the annulus A between the conduit (38) and the inner peripheral surface of the enlarged bore hole (D). In one embodiment (FIG. 12), the drill string (10B) is encased in cement in the initial bore hole (B) and forms a casing for receiving a small diameter production cable.

Acoustic Determination of Producing Bottomhole Pressure

Abstract: This paper discusses the acoustic determination of producing bottomhole pressure (BHP). Two different techniques are presented for wells that have liquid above the formation and gas flowing upward through the gaseous liquid column. One technique involves the acoustic measurement of the liquid level and the casing-pressure buildup rate when the casinghead valve is closed. When these data are used along with an empirically derived correlation given here, the gradient of the gaseous liquid column in the annulus can be obtained. This technique offers a reasonably accurate procedure for determining the producing BHP of a well by acoustic means. The second method involves two acoustic measurements. A backpressure valve is used in the casing head to depress and to stabilize the liquid level at two positions while the well is produced at a constant rate. The gradient of the gaseous liquid column is then calculated and extrapolated to the formation depth. This paper discusses results from the field testing of numerous wells where the actual gradients of gaseous liquid columns were measured in a variety of casing/tubing sizes, oil gravities, gas flow rates, and pressures.

Lip seal assembly for a rotatable shaft

Abstract: An annular seal assembly for sealing an enclosed rotatable shaft. An annular sealing element is frictionally retained between portions of inner and outer metallic cases. The sealing element includes a sealing annulus and a reinforcing annulus which are disposed in laminar fashion and retained between the outer and inner cases. The sealing annulus is deflected by and sealingly engages the outer surface of the shaft when inserted therein. The reinforcing annulus is formed of silicone and is disposed adjacent to the sealing annulus so as to urge the sealing annulus into sealing engagement with the enclosed shaft, particularly when the sealing annulus is cold or when the shaft is highly eccentric. The reinforcing annulus is responsive to an increase in temperature or to an absorption of liquid for increasing in size, thereby reducing the amount of compressive force exerted thereby against the deflected portion of the sealing annulus.

Thermal shield for drilling motors

Abstract: A thermal jacket shield for a drilling motor which permits drilling operations in high temperature wells without failure of the motor. The thermal shield includes a multiple passageway casing to shroud the motor and through which is circulated drilling fluid used to operate the drilling motor. The motor is positioned within concentric inner and outer shells which form a fluid annulus through which the fluid is circulated. An intermediate housing sub connected to the lower end of the drilling motor includes a nozzle through which a controlled quantity of drilling fluid is passed into the annulus formed by the inner and outer annular shells. Outlet ports in the outer shell allow the drilling fluid to flow to the exterior of the tool. As a result, cooling fluid is continuously passed through the jacket shield to maintain the operating temperature of the motor at an acceptable temperature.

Annulus valve for concentric tubing hangers

Abstract: An improved valve for controlling flow through a tubing hanger in a unit having a concentric tubing system and includes upwardly facing recesses or blind pockets in the hanger with a valve member in each of said pockets and having circumferential seals around its upper end and around its lower enlarged end, the valve members are biased upwardly in their pockets by springs and by annulus pressure which is transmitted to the lower end of the valve members through valve passages, the valve members each includes an upper projection or rod which is engaged by an annular actuator controlled responsive to a downwardly exerted spring force and by a pressure area differential which is exposed to annulus pressure and control pressure to urge the annular actuator downwardly which movement moves the valve member to its downward or open position. Control line pressure is provided to the actuator and to the exterior surface of the valve members below their upper seals so that the movement of the valve members can be controlled from remote locations.

Transducer for arranging in a fluid, particularly for the measurement of the flow-velocity of a fluid in a pipe, by transmitting/receiving sonic pulses

Abstract: A transducer for arranging in a fluid particularly for the measurement of the flow velocity of a fluid in a pipe by transmitting/receiving sonic pulses, is designed as a cupshaped metal body (5), whose base (2) as membrane (3) is assigned an electrode (4) on its inside, which is sealed off against the environment, i.e. against the fluid, and whose cup wall is designed with an annulus (6) filled with a powerful damping material (8), for example epoxy , rubber or epoxy mixed with metal particles.

Wireline hydraulic isolation packer system

Abstract: A unitary assembly (10); is disclosed for isolating a leak in a side pocket mandrel (12) between the tubing annulus (16) about a tubing string (14) and the interior (20) of the tubing string. The unitary assembly includes an upper packer (22), and a lower packer (24) interconnected by a tailpipe (26). The upper packer (22) is preferably set by a wireline tool and the lower packer is preferably set hydraulically. This eliminates the need for a drilling or workover rig to be setup over the well when patching a leak.

Method for operating a well to remove production limiting or flow restrictive material

Abstract: A method and downhole well installation for facilitating the removal of detrimental material such as sand accumulated within a well penetrating a subterranean hydrocarbon formation. A tubing string in the well extends to a production interval open to the formation. A production stinger is slidably disposed in the tubing string and extends downwardly from the bottom of the tubing string into the production interval. A seal is provided between the stinger and the tubing string which permits slidable movement of the stinger but provides for a seal against fluid flow upwardly in the stinger-tubing string annulus. A longitudinal passage extends through the stinger and opens into the tubing string above the seal. At least one inflow opening to the longitudinal passage is provided in the stinger near the bottom thereof. Thus, when the stinger comes to rest upon the sand or other unwanted material accumulated in the well, the inflow opening is located adjacent the surface of the unwanted material. A pressure gradient is established through the inflow opening into the stinger passage. Fluid such as gas from the formation flows through the inflow opening into the longitudinal passage and entrains particulate material and carries it to the stinger passage to form a fluid stream containing entrained particulate material. The fluid-particulate material mixture passes upwardly through the stinger passage and into the tubing string above the seal.

Apparatus for sealing a tubing string in a high pressure wellbore

Abstract: Method and apparatus for hanging and sealing a tubing string in a high pressure wellbore. The invention discloses apparatus which enables the pulling of a tubing string on an injection well to be achieved without having to kill or bleed down the formation pressure. A support and flow control apparatus is provided for supporting the upper end of a tubing string that extends downhole in a cased borehole, while packing off the annulus between the tubing and the casing. The apparatus includes a tubing hanger which is connected to the upper end of the wellbore for supporting the upper end of the tubing string therefrom so that the string is in tension. The tubing hanger includes a hollow member having a boss formed thereon by which the hollow member is received in seated relationship within the support and flow control apparatus, and further includes a main body having a vertical passageway and a horizontal passageway formed therethrough in intersecting relationship respective to one another so that the two passageways are disposed perpendicularly respective to one another.

Method and apparatus for perforating a well

Abstract: A method and apparatus for perforating a subsurface formation in a pumped well. An assembly is provided which facilitates both the support of a pump in a tool string and the convection of fluid, and pressures, around the pump in the tool string. A firing head associated with the perforating gun is actuated by a pressure of differential between the tubing string bore and the wellbore annulus. This pressure differential is achieved by a downhole pump which pumps fluid out of the wellbore into the tubing string bore.

Method for cementing a production conduit within an underground arcuate bore

Abstract: An apparatus and method for drilling a bore hole (B) along an underground arcuate path (P) between two surface locations (O,E). The bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section 12 with a drill bit (14) thereon. Drilling fluid is supplied to the drill bit (14) during the drilling operation. Upon completion of the initial bore hole (B), the hole (B) may be enlarged by a reamer (40). Then, a production conduit (38) is connected to the reamer (40) for being pulled by the drill string (10) through the enlarged bore hole (D). Cement is supplied through the drill string (10) for discharge at the reamer (40) into the bore hole (D) adjacent the leading end of the production conduit (38) and fills the annulus A between the conduit (38) and the inner peripheral surface of the enlarged bore hole (D). In one embodiment (Figure 12), the drill string (10B) is encased in cement in the initial bore hole (B) and forms a casing for receiving a small diameter production cable.

Drill stem test method and apparatus

Abstract: Means for lifting formation fluid to the surface in a drill stem test. The drill string has first openings allowing entry of formation fluid and upwardly spaced second openings which are normally closed by a sleeve slidably mounted on the drill string. Fluid pressure from within the drill string impinges on a transverse surface of the sleeve and forces it down, allowing treatment fluid to enter the drill string from the annulus between the drill string and the well bore. A jet pump comprised of a flow constriction creating a venturi effect causes treatment fluid to accelerate upwardly in the drill string, the circulation of the treatment fluid drawing the formation fluid to the surface. The second openings covered by the sleeve include the fluid crossover of the jet pump. A standing valve in the drill string between the first and second openings allows down hole shut-in and pressure build-up tests.

Apparatus and process for pumping fluid from subterranean formations

Abstract: Apparatus for pumping fluid from a subterranean reservoir. The apparatus has in combination a well casing and a hollow tube disposed concentrically within the well casing. Secured to the end of the hollow tube is a hollow housing which includes a motor and a pump driven by the motor. An entrance conduit extends down the annulus between the tubing and the casing and carries a refrigerant working fluid which drives the motor in order to operate the pump which pumps subterranean fluids from the housing through the hollow tubing up to the surface of the earth. A return conduit extends from the hollow housing through the hollow tubing up to the surface of the earth. After the refrigerant working fluid expands and drives the motor, it is initially cooled. Subsequently, the refrigerant working fluid passes into the top of the hollow housing where it is vaporized within the return conduit as the return conduit is in contact with hot subterranean produced formation fluids. The vaporized refrigerant rises in the returning conduit due to the difference in pressure from the bottom of the hole to the surface of the earth.

Apparatus and method for effecting chemical reactions

Abstract: A reaction apparatus (20) having an externalized heat exchange mechanism by which heat may be added to or withdrawn from a reactant mixture. In one aspect, a cased well (24) extends into the earth in which at least one reaction vessel (50) is suspended from a support plate (40) at substantially ground level surface (22). The reaction vessel comprises an outer closed-end tube (55) in which an inner open-end tube (60) is disposed in a concentric manner to define an annulus (70) which is in flow communication with the bore of the inner tube. Substantially parallel to the reaction vessel and also suspended from the ground level support plate, is a conduit (45) which extends into the chamber defined by the well-casing. A mixture of reactants is injected into the annulus of the reaction vessel to form a hydrostatic column which exerts substantial fluid pressure at a reaction zone in the lower part of the reaction vessel. A heat-transfer medium is heated to an elevated temperature and then flowed through the conduit into the chamber (30) where the hot heat-transfer medium envelops the reaction vessel. Heat is transferred from the heat-transfer medium to the reactant mixture through the wall of the outer closed-end tube. In the case of an exothermic reaction, when the temperature of the reactants reaches a selected level, the reaction process gives off heat which is withdrawn by the heat exchange medium. As the reactants form reaction products, the reaction products are flowed from the annulus through the bore (65) of the inner tube back up to ground surface level. In another aspect more than one reaction vessel is suspended in a single chamber in a single subterranean shaft. In still another aspect each reaction vessel comprises an inner open-end tube concentrically arranged inside a larger intermediate closed-end tube which is then surrounded by a larger tube to form a heat exchange annulus. Also suspended in the chamber with the reaction vessel is a conduit through which heat-transfer medium is pumped into the chamber during operation. The chamber is partitioned into an upper portion and a lower portion by packing assemblies or by pressurizing the upper portion with an inert gas. As heat-transfer medium flows into the chamber it is confined to the lower portion of the chamber and forced upwardly through the heat exchange annulus which is in heat-transfer relation to a hydrostatic column of reaction products in the inner reaction vessel annulus.

Apparatus for perforating a well

Abstract: A firing head for a well perforating gun comprises a housing (62,63) defining a first chamber (68) which in use is subject to the fluid pressure in a tubing string, and a second chamber in fluid communication with the well annulus surrounding the head in use. A piston (140) is displaceable by pressure in the first chamber to release a locking assembly (116) to permit a firing piston (114) to be actuated by pressure in the second chamber to fire a detonation assembly (82).

How six parameters affect BHT during circulation

Abstract: Deeper drilling and consequently hotter formations make knowledge of circulation temperature important for optimizing design of drilling fluid. The effect of six parameters that will influence the temperature has been evaluated. They are: 1. Well geometry: annulus, drill pipe, and hole size; 2. Mud pump rate; 3. Mud inlet temperature; 4. Geothermal gradient; 5. Heat transfer coefficient; 6. Depth. Computer programs were developed to solve the differential equations presented in the Holmes model. The model was used to calculate down-hole circulation temperature in an idealized well. For this analysis, the drillstring is not varied and no casing is assumed. The temperature profile of the mud in the drill pipe and in the annulus is shown. The rate of increase in the temperature decreases at about two-thirds of the total depth. This phenomenon also was demonstrated by the Crawford model. The findings regarding the various effects are given in this article.

Method and apparatus for perforating well bores

Abstract: of EP0288238A method and apparatus for perforating oil well casing in a well bore, with particular advantage in highly deviated well bores, uses a perforating gun assembly (15) run into the well bore (10) using the production tubing (12). A sliding sleeve (14) is connected in the tubing above the gun and a packer (13) is run in for setting above the sliding sleeve and gun. The assembly is run into the well bore until the gun extends into the highly deviated portion of the bore where the well casing is to be perforated. The packer is set into place, isolating that portion of the well bore below the packer from that portion above the packer, and the sliding sleeve is opened using a wireline or other means. The well bore below the packer is pressurized through the tubing to ensure that the packer is properly set. The pressure is then allowed to bleed off and the sliding sleeve is closed. The gun uses a differential pressure-actuated firing head which is actuated upon a predetermined differential pressure between the production tubing bore and the annulus between the tubing and the casing. Thus, a well casing can be perforated using relatively low values of actuating pressure, which provides greater control over perforating conditions such as underbalance.

Internal mix spray gun cartridge

Abstract: An internal mixing chamber wherein a small amount of secondary fluid is introduced through a circumferential orifice having circumferential rotation and a large amount of primary fluid is introduced as an axial annulus to flow axially through the radially introduced secondary fluid to be mixed therein. The secondary fluid is introduced at lower pressure than the primary fluid and the system is self-balancing.