Abstract: In one aspect of the invention apparatus and methods are provided for completing a wellbore using expandable sand screen. An apparatus including a section of expandable sand screen, and an expanding member is disposed in the wellbore on a tubular run-in string. Thereafter, the expandable sand screen is expanded in a producing area of the wellbore.

Abstract: A method and apparatus for fracturing a formation or gravel packing a borehole extending through an unconsolidated subterranean zone in a formation includes a screen assembly having a length adapted for disposal adjacent the unconsolidated subterranean zone and includes a plurality of screens mounted on a base member with adjacent base members being connected by a sub having an aperture in the wall thereof. A flow-control service assembly is disposed within the bore of the screen assembly and includes an outer tubular member and an inner tubular member. The outer tubular member includes a plurality of ports that communicate with the apertures in the screen assembly. The apertures in the screen assembly are disposed along the length of screen assembly at predetermined intervals. The inner tubular member and outer tubular member form an inner annulus, the outer tubular member and screen assembly form a medial annulus, and the screen assembly forms an outer annulus with the wall of the borehole.

Abstract: A downhole debris filtering apparatus is disclosed. In a preferred embodiment, the flow diverter is retracted as the tool is run in to provide easy passage for debris. Settling velocity is the rate at which debris will fall through the fluid. Settling velocity is dependent on the density of the fluid and the debris density. If the fluid velocity exceeds the settling velocity, the debris will rise. The restricted annular area outside the screens raises the fluid velocity. Above the cup sleeve, the annular area increases significantly and the fluid velocity is reduce to below the settling velocity to allow debris to settle to the bottom of the tool. On run in, the fluid merely bypasses on the outside of the filter. Large debris will settle into the tool as described. When pulled out of the hole the swab cup/flow diverter is actuated into casing or liner wall contact and a large passage is opened to allow flow though the filter.

Abstract: An apparatus and operating method allows the completion of multiple production zones in a single wellbore with a single downhole trip. The work string descends with a coaxially combined completion string and service string. The completion string is set into a previously set basement packer. The completion string includes a series of production screens, transverse flow orifices, isolation packers and collet indicating couplings, all prepositioned along the completion string length relative to the basement packer set location. The production sleeves and transverse flow orifices are selectively closed by axially sliding sleeves. The service string includes a crossover flow tool, a SMART collet tool, sleeve shifting tools and sleeve closing tools. With all orifice and screen closure sleeves closed, the procedure proceeds from the lowermost production zone to open the closure sleeves respective to the flow orifice and screens dedicated to a respective production zone.

Abstract: A well completion is provided to enable sand-control treatment of one or more production zones with only a single trip into a well. In one example arrangement, the completion may include a first, second and third packer. The first packer may be attached to a production tubing. A first sand screen may be disposed between the first and second packers. A first closing sleeve may be disposed between the first packer and the first sand screen. A first surface controlled flow control device may be disposed between the first sand screen and the second packer. A control conduit extending from the earth's surface is sealably passed through the first packer and connected to the first surface controlled flow control device. A second sand screen is disposed between the second and third packers. A second closing sleeve may be disposed between the second packer and the second sand screen.

Abstract: A leak integrity testing apparatus (36) is provided which is adapted to be inserted within a liquid-delivery line, as for example an oil well tubing string (26), to permit in situ testing of the line or string (26) without the need for removal or inspection of the line. The apparatus (36) is a tubular body preferably including an interconnected tubular inlet (38) and outlet (40); a liquid pressure-responsive, metallic burst disc (42) is located between the inlet (38) and outlet (40). The disc (42) includes a peripheral flange (62) and an inner concavo-convex burst region (64). A score line (82, 86) is located on the concave face (66) of the burst region (64), and is of differential depth, having a reduced-depth hinge area (84, 88) serving to prevent detachment of the burst region (64) upon actuation of the disc (42).

Abstract: An apparatus for use in a wellbore having a tubing includes a flow control assembly having at least one orifice and a bore capable of communicating with a bore of the tubing. The flow control assembly includes at least one valve adapted to control fluid flow through the at least one orifice to the bore. The at least one valve is adapted to be actuated between an open position, a closed position, and at least an intermediate position. A sand control assembly is coupled to the flow control assembly and includes a sand screen and a flow path defined inside the sand screen in fluid communication with the at least one orifice.

Abstract: A system for use in a wellbore includes a tubing having an inner bore and flow switcher assembly. The flow switcher assembly including a first conduit coaxial with the tubing inner bore and a second conduit formed annularly around the first conduit. One of the first and second conduits is adapted to carry production fluid flow, and the other one of the first and second conduits is adapted to carry injection fluid flow. The flow switcher assembly includes ports in communication with the first and second conduits to enable cross-over flow. In addition, one or more valves may be provided to control fluid flow through the ports.

Abstract: A combination collar based retrievable drilling fluid filter and wiper with threaded ends for easy inclusion within the drill string, and a through bore for passage of drilling fluids and insertion of a wire line retrievable filter and wiper unit which is concentrically received and supported by the collar. The filter and wiper unit include a filter insert and an elongated wiper carrier. The filter insert is positioned at an upper end of the apparatus and is received by the elongated wiper carrier which is positioned at the lower end of the apparatus. The elongated wiper carrier includes numerous wiper brushes which help remove scale from the interior of the drill string when the filter and wiper unit is retrieved. Electrical wiring passes easily through the apparatus for operation of down hole instruments if desired.

Abstract: A proppant containment apparatus and associated method of using the apparatus permit continued delivery of a proppant slurry to a subterranean wellbore after failure of a crossover portion of the apparatus during a fracturing operation, eliminating the need to stop the fracturing operation and remove and replace expensive items of equipment after such crossover failure. In a preferred embodiment, the proppant containment apparatus has a tubular crossover member with an internal flow passage, circulation port, and side wall outlet openings, first and second coaxial tubular structures, the first tubular structure being perforated, a tubular screen positioned between the first and second tubular structures, a ball, and a ball seat having a spaced series of grooves formed thereon.

Abstract: Methods and apparatus provide desired levels of continuous fluid pressure in a portion of a wellbore during completion operations. In a described embodiment, a method permits continuous fluid communication between a tubular string extending to the earth's surface and a portion of a wellbore below a packer during testing of the packer. This fluid communication enables a desired fluid pressure to be continually applied to a filter cake lining the portion of the wellbore, to aid in preventing compromise of the filter cake and possible collapse of the wellbore portion. A packer test device included in the apparatus permits such fluid communication during testing of the packer.

Abstract: A formation fracturing and gravel packing tool and associated methods provide high flow rates and volumes of slurry delivery in a relatively small bore well. In a described embodiment, a formation fracturing tool has a telescoping travel joint and a washpipe within an assembly including a packer, a circulating sleeve and a screen. The packer is set in the well, the travel joint is extended, the travel joint is locked in its extended configuration, a slurry is flowed through the circulating sleeve, the extended travel joint is latched onto the washpipe, and the travel joint and washpipe are retrieved to the earth's surface.

Abstract: A monitoring well including a conduit defining a passageway, the conduit having a proximal and opposite, distal end; a coupler connected in fluid flowing relationship with the passageway; and a porous housing borne by the coupler and connected in fluid flowing relation thereto.

Abstract: The present invention provides a fluid flow control device for controlling the formation fluid flow rates through a production string. The device includes a generally tubular body for placement into the wellbore. The tubular body has a screen at an outer surface for preventing sand from entering into tabular body. The fluid flowing through the screen passes through a labyrinth. A slidable sleeve on the labyrinth controls the fluid velocity there through. The slidable sleeve screen is moved by an electrically-operated device, such as a motor paced in the production string. The fluid leaving the labyrinth passes to a tubing in the tubular body for carrying the fluid to the surface. The flow control device further may include a control circuit in the production string for controlling the operation of the electrically-operated device.

Abstract: A method of deploying a well screen and associated apparatus provide convenient and economical completion operations within subterranean wells. In a disclosed embodiment, a method of positioning a screen includes attaching the screen to a completion string before stimulation operations are performed on a formation. Initially, the screen is spaced apart from the formation. After the stimulation operations are performed, the screen is positioned opposite the formation and packers are set above and below the screen. In order to thus position the screen, a work string is inserted into the completion string, the screen is attached to the work string, and the screen is released from the completion string. After the packers are set, the work string may be retrieved and the formation placed in production. The screen and packers prevent flow of particulate material from the formation into the completion string. Other methods are provided as well.

Abstract: A proppant containment apparatus and associated method of using the apparatus permit continued delivery of a proppant slurry to a subterranean wellbore after failure of a crossover portion of the apparatus during a fracturing operation, eliminating the need to stop the fracturing operation and remove and replace expensive items of equipment after such crossover failure. In a preferred embodiment, the proppant containment apparatus has a tubular crossover member with an internal flow passage, circulation port, and side wall outlet openings, first and second coaxial tubular structures, the first tubular structure being perforated, a tubular screen positioned between the first and second tubular structures, a ball, and a ball seat having a spaced series of grooves formed thereon.

Abstract: A retrievable screen apparatus provides increased filtration in a retrievable screen disposed within a receptacle, the receptacle being positioned in a subterranean well. The receptacle has a lower filtration screen attached thereto for filtering larger particles, such as gravel and proppant, from fluid flow within the well. Thus, the retrievable screen may be retrieved and replaced, leaving the receptacle operatively positioned in the well.

Abstract: The invention relates to a filter which is useable in conjunction with subsea hydraulic control circuits. The filters incorporated in a housing which can be stabbed in or out of a control unit to become part of one or more fluid control circuits. The stab-type housing can be inserted with a remotely operated vehicle. Other configurations involve long, slender housings for use with subsurface safety valve control lines as well as with tubing hanger housings. The slender design allows mounting right on the production tubing. A rupture disc feature is available so that if excessive pressure differential is obtained due to clogging, the filter unit within the housing can be bypassed to allow continuing operation.

Abstract: A gravel-packing apparatus and method is disclosed which involves a movable sleeve over a screen. The screen is fixed to a packer downhole while the sleeve is operated from the surface. As the sleeve is lifted to expose more of the screen, the granular material deposits along the outside of the screen and through the exposed perforations, starting from the packer and working its way up. The annulus is sealed by multiple cup seals or other suitable seals for the environment so that the slurry pressure applied from the surface is directed to deposition of the granular material adjacent the exposed perforations. As more granular material is deposited, the crew at the surface may further pull the sleeve up or the developed pressure downhole itself can force the sleeve further up, exposing additional perforations and continuing the deposition process of the granular material.

Abstract: The invention involves an assembly, specifically beneficial in deviated well-bores, which allows running into the wellbore with the complete completion assembly. The completion assembly includes one or more screens which may be pre-packed. Initially, a material which sets to form a permeable mass is deposited in the annular space outside the screens. After such material is deposited, cement or other sealing material is pumped into the annular space above the screens to complete the completion process. As a result, in one trip the deviated wellbore is completed with the permeable material deposited outside the screen or screens and cement being disposed in the annular space above the permeable material. Production can then begin.

Abstract: A well completion system which includes a production packer assembly, production tubing sealed to the packer assembly, and an isolation assembly coupled with the packer assembly. The isolation assembly includes an isolation pipe received within a production screen and sealed at both ends therewith. The isolation pipe defines at least one port and carrying a moveable sleeve defining at least one aperture. The sleeve is moveable between an open position in which the port and aperture are in communication to permit fluid flow therethrough, and a closed position in which the port and aperture are not in communication and fluid flow is prevented. The isolation system is also coupled with a wash down shoe and a shearable ball seat.

Abstract: Disclosed is an improvement in a prepacked well screen assembly which includes coating the granular material in the filter medium with a resin system including an oligomer of furfuryl alcohol, a catalyst including an oil soluble, slightly water soluble organic acid, and an ester of a weak organic acid to consume water produced by the polymerization of the resin.

Abstract: Preperforated tubing is produced by forming a perforation in flat strip of raw material, forming a hollow, cylindrical tube from the flat strip, and placing a removable plug into the perforation, so as to form a fluid-tight seal. A sealing element may be placed into the perforation. The perforation may comprise a hole, into which first and second countersinks may be formed. The sealing element may be placed into the first countersink, and the plug may be placed through the countersinks and the hole, such that the plug's body fills the hole and the plug's head fits within the second countersink.

Abstract: A gravel-packing apparatus and method is disclosed which involves a movable sleeve over a screen. The screen is fixed to a packer downhole while the sleeve is operated from the surface. As the sleeve is lifted to expose more of the screen, the granular material deposits along the outside of the screen and through the exposed perforations, starting from the packer and working its way up. The annulus is sealed by multiple cup seals or other suitable seals for the environment so that the slurry pressure applied from the surface is directed to deposition of the granular material adjacent the exposed perforations. As more granular material is deposited, the crew at the surface may further pull the sleeve up or the developed pressure downhole itself can force the sleeve further up, exposing additional perforations and continuing the deposition process of the granular material.

Abstract: Method and apparatus for gravel packing wells are provided. Selected intervals of wells may be fractured before gravel packing. The open area of a screen device and the number of perforations exposed to slurry are increased as gravel is pumped into a well during gravel packing operations. Means for creating back-pressure on perforations not yet covered with gravel is provided to decrease flow of particles into the casing during gravel packing operations. Gravel pack screen assemblies by which flow area can be incrementally increased are disclosed, along with apparatus for providing desired back-pressure on open perforations.

Abstract: A gravel pack well tool comprised of a workstring having a gravel pack screen thereon wherein the workstring can be rotated without applying any substantial torque to the screen jacket which forms part of the gravel pack screen. This allows the workstring to be rotated in either direction during installation or removal of the gravel pack screen without damaging the screen jacket. The gravel pack screen is comprised of a fluid-permeable base pipe having a screen jacket rotatably mounted thereon.

Abstract: A gravel pack screen assembly adapted to produce fluids from two spaced apart zones of interest through gravel packing surrounding spaced apart gravel pack screens includes a sub interposed in the screen assembly between the two screens and having a reservoir for discharging a quantity of permeability reducing material into a layer of gravel packing intermediate the gravel packing surrounding each of the screens. The sub is operable to discharge the material into the gravel pack layer in response to movement of a washpipe or the like within the screen assembly to move an actuator member to cause a closure member to uncover ports in the sub in communication with the reservoir. The actuator member includes a transverse surface projecting into a central bore of the sub and operable to be engaged by deflectable collet fingers formed on a washpipe assembly or a similar member insertable within the gravel pack screen assembly to effect operation of the sub to discharge its permeability reducing material.

Abstract: A sand screen having a plurality of sintered, substantially spherical plastic members covering a perforated mandrel is releasably suspended from a packer mandrel by a locking mandrel and a landing nipple. The sand screen and locking mandrel are retrievable with the assistance of a running tool which is insertable into the bore of the locking mandrel. According to this arrangement, the sand screen can be removed and replaced without retrieving the packer or the production tubing. In one embodiment, the sand screen is enclosed within the bore of a sliding side valve. The sliding side valve can be opened and closed as desired for selectively admitting production from various producing zones, or for isolation of a damaged screen. In another embodiment, an auxiliary sand screen having a plurality of sintered, substantially spherical plastic members covering a perforated mandrel is inserted into the bore of a primary screen, for example, a conventional wire-wrap sand screen.

Abstract: A gravel pack well tool for use in a gravel pack completion which does not require the circulation of fluids during installation. The gravel is first placed or preset within the completion zone and then the well tool having a auger-liner assembly is lowered and rotated into the preset gravel. The liner assembly is comprised of a fluid-permeable linear surrounded by a torque sleeve which transmits torque from a workstring to a nose sub at the leading edge of the liner assembly. The nose sub has a fish-tail bit thereon to assist the downward movement of the liner assembly into the preset gravel and has passages therein for fluid flow therethrough in the event the assembly becomes stuck in the gravel during installation.

Abstract: A method and apparatus for controlling the intrusion of steam (e.g. breakthrough) from a zone of a producing formation into a slotted liner of a gravel-packed, production well of a steam flood recovery operation. An assembly including a blank, scab conduit is lowered into the upper portion of the slotted liner to effectively block those openings in the slotted liner which lie adjacent the steam intrusion zone. A seal, (e.g. deformable metal seal, metal seal rings, etc.) is provided at the upper end of the blank conduit to block upward flow between the liner and blank conduit when the blank conduit is in place. In a further embodiment, a second set of seals can be provided to block the downward flow of steam between the blank conduit and the slotted liner.

Abstract: Method and apparatus for gravel packing wells are provided. The area available for flow of fluid through a screen device is increased as increasing amounts of gravel are pumped into the well. External or internal means for increasing flow area are provided. Gravel pack screen assemblies by which flow area can be incrementally increased are disclosed.

Abstract: A gravel pack screen assembly includes a bit or sub having a flow passage which may accept a wash pipe. The wash pipe may be inserted past a flapper-type closure member which moves to a closed position upon withdrawal of the wash pipe after completion of the installation of the gravel pack assembly. The closure member can be formed of a porous material to permit the flow of liquid through the bit or sub flow passage into the interior of the gravel pack screen but to prevent flow of gravel packing or produced sand into the interior of the screen. The closure member may serve as a backup to a conventional one-way valve and permit additional gravel pack material to be placed in the flow passage upon completion of the gravel pack installation and in the event of early or late failure of the one-way valve.

Abstract: The flow apertures of a perforated mandrel are temporarily sealed by a foil covering sheet which is made of a sacrificial material, for example, zinc, aluminum and magnesium The sacrificial covering sheet prevents dirty completion fluid from passing through and in and out of the screen as it is run into the hole, thereby protecting the screen from plugging. During the time the screen mandrel is temporarily sealed by the sacrificial foil covering, cleaning fluid is circulated through the work string and is returned through the annulus between the screen and the open well bore for removing filter cake, drilling debris and lost circulation material. After the annulus has been cleaned, the annulus is filled with an acid solution or caustic solution, which dissolves the sacrificial foil and opens the base pipe perforations.

Abstract: A sintered metal screen is releasably suspended from a packer mandrel by a locking mandrel and a landing nipple. The sintered metal screen and locking mandrel are retrievable with the assistance of a running tool which is insertable into the bore of the locking mandrel. According to this arrangement, the sintered metal sand screen can be removed and replaced without retrieving the packer or the production tubing. In one embodiment, the sintered metal screen is enclosed within the bore of a sliding side valve. The sliding side valve can be opened and closed as desired for selectively admitting production from various producing zones, or for isolation of a damaged screen. In another embodiment, an auxiliary sintered metal screen is inserted into the bore of a primary screen, for example, a conventional wire-wrap sand screen.

Abstract: A method and apparatus for installing a gravel pack well completion wherein flow of fluid in the well can be effectively blocked and excessive hydrostatic pressure can be isolated from the top of a pre-placed column of gravel while an auger-liner assembly is rotated into the gravel. Basically, gravel is first placed within the zone after which a liner is lowered on a workstring and the liner is augered into the pre-placed gravel. A packer cup and by-pass assembly is coupled into the workstring having cup packers which effectively block flow within the well during installation of the liner. The cups are mounted on a rotatably mounted sleeve so that the workstring can be rotated while the cups are expanded against the well casing. The packer cup and by-pass assembly includes a bypass which can be opened after the liner has been placed so that the workstring can easily be withdrawn from the well.

Abstract: Under-balanced or potential fluid cross-flow conditions in a wellbore are minimized during installation of an auger-type gravel pack screen by placing a quantity of fine salt, calcium carbonate paste, a fluid loss control gel or sand within the interior space of the screen liner so that the material will form a substantially impermeable barrier on the liner, the gravel packing or the face of the formation during or after installation of the screen to minimize fluid flow in wells which have a relatively high pressure gradient. The material may be removed at will by circulation of a dissolving liquid such as fresh or unsaturated water or mechanical removal of insoluble material such as sand.

Abstract: Method and means for preventing fluidization or mobilization of a gravel pack in a fluid producing well as a result of increased fluid pressure caused by a well shut-in or other pressure surge. A pressure relief valve in the form of a check valve is provided in a tubing string below a packer surrounding the string and above the top of the gravel pack. The check valve is held in closed position by a biasing force, such as a spring, which is less than the pressure which will cause mobilization or fluidization of the gravel pack. A pressure surge such as a well shut-in or flow rate decrease increases tubing pressure which causes the check valve to open, thereby relieving the pressure in the gravel pack to a point below the critical level.

Abstract: A method of gravel packaging a well penetrating and in fluid communication with a subterranean formation or zone by sealing the apertures of a gravel pack liner, except near the bottom of the liner, against entry of slurry fluid. This prevents gravel from clogging the apertures or bridging the annulus between the liner and the well bore. An immobile gel provides the sealing function, and a breaker eventually breaks the gel, thereby permitting removal of the gel and unblocking the apertures. The gel is formed from a suitable liquid composition containing the gel breaker, and may be applied to the liner prior to lowering the liner and wash pipe into the well bore.

Abstract: A method and apparatus for installing a gravel pack completion which does not require the circulation of fluids during installation. The gravel is first placed or preset within the completion zone and then a well completion tool (e.g. a fluid-permeable liner) having an auger blade thereon is lowered and rotated into the present gravel without circulating fluid through the tool. Since the auger blade mechanically displaces the gravel upward as the tool is moved into the preset gravel, there is no need to flow fluid under pressure to "fluidize" the gravel as is required in prior completions of this type.

Abstract: A downhole pump filter filters sand and other solid particles from well fluids prior to passage of the fluids through the intake nut of a well pump. A cylindrical coupling has an externally threaded upper end which coaxially screws into the pump intake nut. The coupling also has an externally threaded lower end. A tubular member coaxially secured within the lower end of the coupling has a plurality of perforations dispersed at least along its lower portion. A filter sock may encase the perforated portion of the tubular member to block smaller sand or other solid particles from entry into the tubular member perforations. A cylindrical casing with a closed lower end and an internally threaded upper end coaxially screws onto the exxternally threaded lower end of the coupling with the tubular member and the filter sock disposed within the casing. The casing has a plurality of perforations dispersed at least along its lower poriton.

Abstract: A well completion assembly is constructed to be run on a tubing string into a well. The well can be gravel packed and subsequently opened to production without removing the tubing string from the well. The well completion assembly includes a packer, and a screen located below the packer. A gravel packing and production control assembly is located between the packer and the screen for initially permitting flow of gravel packing slurry down the tubing string and into a lower well annulus surrounding the exterior of the screen, and for subsequently permitting production of well fluids through the screen into the interior thereof and up through the tubing string without tripping the tubing string out of the well.

Abstract: The gravel pack system includes a crossover assembly disposed within a screen assembly which has been adapted for disposal adjacent a producing formation within a well. The screen assembly includes a packet for sealing the annulus between the screen assembly and a well casing and a production screen disposed below the packer. The crossover assembly includes a wash pipe and a crossover tool adapted for suspension within the well on a pipe string for disposal within the screen assembly. Upon the disposal of the crossover assembly within the screen assembly, the assemblies together form an upper crossover valve, a lower crossover valve, a circulation valve, and a screen valve. These valves are selectively opened and closed for the various gravel pack operations by raising the crossover assembly within the screen assembly.

Abstract: The present invention provides an apparatus and method of completing a water well and preparing the well for placement of a pump for production of water, including the steps of setting a well screen, setting a packing seal, packing the annular space between the well screen and the well bore, and air jet cleaning of contaminated water from the well bore, in a single run down the well bore. The apparatus includes a well seal and screen retainer portion to be left in the well bore, a sand distributor portion, and an air jet portion, all coaxially aligned and releaseably interconnected.

Abstract: An apparatus for placing a filter screen and for packing gravel around the filter screen adjacent a well formation. The apparatus includes a body having a packer portion and a valve portion. The body defines a central passageway therethrough. The valve portion includes a valve mandrel with a valve sleeve slidably positioned therein, and transverse openings in the valve sleeve and valve mandrel are aligned to form a transverse passageway therethrough when the valve is in an open position. A stinger is positionable in the body for closing the central passageway and actuating the valve sleeve between the open and closed positions thereof. When in the open position, the transverse openings in the valve mandrel and valve sleeve are aligned with a transverse opening in the stinger such that fluid communication is provided between a well annulus below the packer portion and the tool string above the apparatus. Collet fingers engage the stinger so that when the stinger is moved from the body, the valve is closed.

Abstract: Improved equipment and methods for treating wells by processes such as acidizing, gravel packing, and the like, wherein provision is made for removing the excess acid, gravel, and the like, from the well while the work string or pipe, on which the equipment is run into the well, remains connected to the well packer. The pipe string is disconnected from the packer only when it is ready to be removed from the well. Provision is also made for repeating the cleanout operation any number of times, making it possible to perform a series of treating operations during a single trip into the well and removing the excess treating medium after each such treating operation in the series.

Abstract: An apparatus is provided for gravel packing a plurality of zones within a subterranean well. Primary sealing means are adapted for setting in casing at a position above the zones. A plurality of sets of production screens and valve means are provided, the valve means being equal in number to the zones to be packed and being carriable in the well with the primary sealing means. Zone isolation means are connected between each said set and expansible into sealing engagement with the casing. A control mandrel includes a single cross-over means for diverting gravel carrying fluid. A plurality of vertically spaced sealing means are defined on the cross-over means for successively isolating each set from the others when the cross-over means is positioned in proximity to each valve means. Valve opening means are provided on the control mandrel and are operable by longitudinal movement of the mandrel to positions for opening and closing the valve means.

Abstract: The invention provides a system and method for recovering organic liquid such as gasoline which has settled on the water table in underground areas. The system comprises a conduit extending from the ground surface to a point just above the water table, a collection head fitted on the lower end of the conduit, a collection vessel connected to the upper end of the conduit and an exhaust means for creating less than atmospheric pressure in the vessel. The collection head has a liquid impermeable end portion and a liquid permeable intermediate portion for permitting the passage of liquid.

Abstract: A device for preventing unwanted objects from entering the ball assembly of a float collar or float shoe and otherwise damaging or plugging the valve mechanism therein is disclosed. The device comprises a screen constructed of expanded metal and rigidly affixed to the interior of the float collar or float shoe above the ball valve assembly. The screen portion is either mounted to the interior surface of the float collar sleeve by an annular structural member or mounted to a structural band which is partially embedded in the concrete portion of the float collar or casing guide shoe.

Abstract: A method for cleaning a helical spring screen deep in a well while filtering liquid comprises (1) injecting a high pressure hydraulic surge pulse into the spring screen for expanding the coils, (2) forcing high pressure liquid between the coils of the helical spring screen simultaneously with expanding of the coils for washing the sand from between the coils, and (3) forcing the coils together following their expansion by expanding action of a second spring for crushing and dislodging any sand therebetween the coils for removal upon subsequent spreading of the coils. A second method is disclosed likewise. Thus the methods provide for the spring coils being cleaned for a multiplicity of times without having to shut the well in for workover, thus saving workover costs and lost production.

Abstract: A self-cleaning helical spring sand screen for use at the petroliferous unconsolidated sand strata of an oil well are disclosed. The sand screen comprises a hydraulically actuated, spring based spool valve connected to the upper end of the sand screen for receiving liquid under high pressure, for storing energy in the spring, for expanding the helical spring sand screen, and for ejecting liquid into the helical spring sand screen for cleaning thereof. Then upon ceasing of flow of the high pressure liquid, the stored energy in another spring contracts the helical spring sand screen for restorating production of sand-free oil from the production tube. A second modification is disclosed.