Abstract: The invention is a water well filter. An outer pipe is concentric with an inner pipe. Each pipe has a plurality of water passage apertures. The outer pipe is shorter than the inner pipe, but long enough to cover the apertures of the inner pipe. The outer pipe is attached to non-apertured portions of the inner pipe by sealing rings disposed at an upper and lower end of the upper pipe so as to form a gap between the pipes. The sealing rings are welded onto the inner and outer pipes. A granulated filter material fills the gap. The filter granules may be bonded to each other as well as to the surfaces of the pipes. A nylon mesh cover is disposed on the outer surface of the inner pipe to prevent filter granules from entering through the inner pipe apertures. The inner pipe has an internally threaded portion at one end and an externally threaded portion at the other end so as to allow multiple inner pipes, and thus multiple water well filters, to be attached end to end.

Abstract: A well screen is disclosed for positioning in a well bore to screen solid particles from the fluid produced by the well comprising a base pipe having a perforated wall and threaded connections for connecting the base pipe into a pipe string, a wire screen surrounding the perforated portion of the base pipe, a thin porous membrane comprising an inner layer of cloth of woven ceramic fibers wrapped around the wire screen and covered by a porous sleeve membrane of braided ceramic fibers, means for holding the ends of the porous cloth membranes in sealing engagement with the base pipe, and a perforated tubular metal shroud surrounding the ceramic cloth membranes to protect the membranes from damage when lowered into a well bore.

Abstract: A system for enhancing steam distribution in a thermal stimulation phase, and for reducing the production of particulate matter with hydrocarbon fluids in a production phase, has a base pipe with a limited number of spaced-apart holes. The spaced-apart holes are sized and located so that steam is uniformly distributed in the reservoir. A collar is disposed around each hole to deflect the steam into an annulus between the base pipe and a wire-wrap screen section to avoid erosion and deterioration of the wire-wrap screen, which is required in the production phase. Mobilized hydrocarbon fluids flow to the wire-wrap screen section, which acts to filter particulate matter so that the production of particulate matter with hydrocarbon fluid is limited. The open area in the base pipe is significantly reduced, as compared with conventional methods, so that at the design injection rates, the pressure drop through the spaced-apart holes is larger than the pressure drop along the base pipe.

Abstract: A particle control screen assembly for a perforated pipe used in a well, a sand filter system, and methods of making same are provided. The screen assembly includes a woven mesh filter media disposed about an inner surface of the perforated pipe, and a protective wrapper disposed about the filter media. The protective wrapper comprises a radially inner perforated layer and a radially outer layer that is disposed between the inner layer and the filter media. A surface of the outer layer that faces the inner perforated layer has a non-smooth contour, with this surface of the outer layer having portions in direct contact with an outer surface of the inner layer. The outer layer is provided with apertures that are disposed in such a way that fluid cannot flow from the inner surface of the inner perforated layer directly radially both through holes of the inner layer and through the apertures of the outer layer.

Abstract: A filter capable of being used in subterranean environments includes a filter medium. An erosion barrier is disposed along a common flow path with the filter medium for preventing erosion by particles in a fluid being filtered.

Abstract: A filter for subterranean environments includes an inner support member, a filter body containing a filter medium disposed around the inner support member, and at least one end connector connected to a lengthwise end of the filter body and sealed against the inner support member without being welded to the inner support member. The end connector may be restrained from movement relative to the inner support member in a lengthwise direction of the inner support member, without being welded to the inner support member, to resist axial forces acting on the filter during installation or operation in a well. Alternatively, the end connector may be capable of movement with respect to the inner support member in a lengthwise direction of the inner support member to enable the filter to undergo thermal expansion without damage to the filter body or other portions of the filter.

Abstract: Well screen assembly for use in horizontal wells and other situations where tensile, torsion and bending forces can damage well screens which are welded to their end supports provides a floating mounting which eliminates welding of the screen segments. A pair of complementary inner and outer slip rings are provided at one end of the well screen assembly with the inner ring being in sealed relationship with a screen segment and the outer ring being integrally affixed to an outer protective cover member and an axial support member such as a pipe base member or a tubular end fitting. The inner ring is free to slide and rotate relative to the outer ring.

Abstract: A filter is provided which combines a woven wire mesh over a supporting body. The supporting body is typically a metal perforated tube which provides fluid communication between the well bore and the production equipment string. The woven wire mesh acts as a filter to prevent the influx of sand particles, provides openings oriented at various angles relative to its surface, so that some area is available for fluid entry even when particulate matter is lodged on the surface above an opening, provides interior channels that allow fluid to travel from one location on the mesh surface to another location over an opening into the supporting body, and does not provide "straight-through" openings, thus forcing the fluid to make multiple turns to pass through the mesh, thereby dissipating the fluid's energy and increases the mesh's erosion resistance. When particulate matter accumulates on the mesh's surface, the resulting particle cake remains porous, heightening the filter's resistance to plugging.

Abstract: A particle control screen assembly for a perforated pipe used in a well, a sand filter system, and methods of making same are provided. The screen assembly includes a woven mesh filter media disposed about an inner surface of the perforated pipe, and a protective wrapper disposed about the filter media. The protective wrapper comprises a radially inner perforated layer and a radially outer layer that is disposed between the inner layer and the filter media. A surface of the outer layer that faces the inner perforated layer has a non-smooth contour, with this surface of the outer layer having portions in direct contact with an outer surface of the inner layer. The outer layer is provided with apertures that are disposed in such a way that fluid cannot flow from the inner surface of the inner perforated layer directly radially both through holes of the inner layer and through the apertures of the outer layer.

Abstract: Improved methods and apparatus for completing an unconsolidated subterranean zone penetrated by a wellbore are provided. The methods basically comprise the steps of placing a slotted liner having an internal sand screen disposed therein in the zone, isolating the slotted liner and the wellbore in the zone and injecting particulate material into the annuli between the sand screen and the slotted liner and the slotted liner and the wellbore to thereby form packs of particulate material therein to prevent the migration of fines and sand with produced fluids.

Abstract: A particle control screen assembly for a perforated pipe used in a well, a sand filter system, and methods of making same are provided. The screen assembly includes a woven mesh filter media disposed about the perforated pipe, and a protective wrapper disposed about the filter media. The protective wrapper comprises an outer perforated layer and an inner layer that is disposed between the outer layer and the filter media. A surface of the inner layer that faces the outer perforated layer has a non-smooth contour, with this surface of the inner layer having portions in direct contact with an inner surface of the outer layer. The inner layer is provided with apertures that are disposed in such a way that fluid cannot flow from the outer surface of the outer perforated layer directly radially both through holes of the outer layer and through the apertures of the inner layer.

Abstract: Well casing assembly for use in oil and gas wells, and especially deviated or horizontal wells, has an inner pipe member with threaded ends which permit a number of casing assemblies to be joined in a string. The inner pipe has a series of perforations along a segment of its length which are covered by an elongated screen member which prevents the passage of sand particles. A concentric outer protective cover member is devoid of perforations in regions which are radially opposite the inner screen to prevent damage to the screen. One or more perforated segments of the outer member are axially spaced from the screen member so that inward flow from a formation will have its energy and velocity reduced before it reaches the screen, thereby minimizing erosion of the screen surface. If desired, perforated flow control devices such as annular rings can be located between the inner pipe and outer member at the ends of the screen segment to allow a more uniform flow to the screen, and thus further reduce erosion.

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: A pre-packed well screen has concentric inner and outer fiber reinforced composite tubes with a granular filter medium in the annulus between the inner and outer tubes. The walls of the tubes are slotted for passing fluid through the slots and the filter medium. Each end of the inner tube extends beyond the adjacent end of the outer tube and has a male thread. A connection is made to an adjacent well screen or other tube by a female coupling member threaded onto the male thread. An advantage of the design is that the coupling member connected to the inner tube has an outside diameter approximately the same as the outside diameter of the outer tube.

Abstract: A filter is provided which combines a woven wire mesh over a supporting body. The supporting body is typically a metal perforated tube which provides fluid communication between the well bore and the production equipment string. The woven wire mesh acts as a filter to prevent the influx of sand particles, provides openings oriented at various angles relative to its surface, so that some area is available for fluid entry even when particulate matter is lodged on the surface above an opening, provides interior channels that allow fluid to travel from one location on the mesh surface to another location over an opening into the supporting body, and does not provide "straight-through" openings, thus forcing the fluid to make multiple turns to pass through the mesh, thereby dissipating the fluid's energy and increases the mesh's erosion resistance. When particulate matter accumulates on the mesh's surface, the resulting particle cake remains porous, heightening the filter's resistance to plugging.

Abstract: A screen provides increased erosion resistance and collapse resistance without uneconomical overcompensation and without requiring an increase in the screen's outer diameter. In a preferred embodiment, a sand control screen has a support material radially between a tubular base pipe and a filtering portion. The support material radially outwardly supports the filtering portion to help prevent radially inward collapse of the filtering portion. In another preferred embodiment, a screen has a coating applied to a filtering portion's exterior surface. The coating may alternatively or combinatively provide erosion resistance, radially inwardly retain a support material, and selectively vary flow through the filtering portion.

Abstract: A particle control screen assembly for a perforated pipe used in a well, a sand filter system, and methods of making same are provided. The screen assembly includes a woven mesh filter media disposed about the perforated pipe, and a protective wrapper disposed about the filter media. The protective wrapper comprises an outer perforated layer and an inner layer that is disposed between the outer layer and the filter media. A surface of the inner layer that faces the outer perforated layer has a non-smooth contour, with this surface of the inner layer having portions in direct contact with an inner surface of the outer layer. The inner layer is provided with apertures that are disposed in such a way that fluid cannot flow from the outer surface of the outer perforated layer directly radially both through holes of the outer layer and through the apertures of the inner layer.

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: An adjustable flow rate screen assembly and associated methods of completing a subterranean well provide variable flow rates through downhole sand control screens without restricting access to the well and without requiring overly restrictive screens to be utilized in gravel packing operations. In a preferred embodiment, a screen assembly has a tubular restrictor housing with a flow passage formed thereon, a tubular ported housing having ports formed radially therethrough and providing fluid communication with the flow passage, and a tubular selector sleeve with an opening formed radially therethrough and permitting fluid communication with a selected one of the ports.

Abstract: A damage-resistant filter for use in subterranean wells has at least one layer of a filter medium, such as a sintered supported porous membrane, coaxially disposed about a perforated support member. The filter may also include a drainage layer disposed between the inner support member and the filter medium, and a protective covering, such as a perforated cage, surrounding the filter medium. The filter is particularly suitable for removal of sand and other particulates from fluids produced in a well.

Abstract: An apparatus for controlling sand production within a wellbore completed to a subterranean reservoir is disclosed. The apparatus will include a base supporting member that has a series of perforations included thereon. A jacket member is disposed about the base supporting member, with the jacket member being a helical member with overlapping loops forming multiple passages for the flow of a subterranean gas and fluid. A protective member disposed about the jacket may also be included, with the protective member having a series of perforations formed thereon.

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: Disclosed is a process for removing contaminants from a contaminated area of the ground having a vadose zone and a water table, which comprises providing a borehole in the contaminated area to a depth below the water table; placing in the borehole to a depth below the water table a first perforated riser pipe; placing inside the first perforated riser pipe a second perforated riser pipe; placing inside the second perforated riser pipe a first vacuum extraction pipe with a bottom opening situated within the second perforated riser pipe; placing a second vacuum extraction pipe within the first perforated riser pipe but without the second perforated riser pipe; while introducing a gas into the second perforated riser pipe, applying a vacuum to the first vacuum extraction pipe and applying a vacuum to the second vacuum extraction pipe to draw gases and liquid from the soil into the first vacuum extraction pipe and the second vacuum extraction pipe and transport both gases and liquid to the surface as two-phase co

Abstract: A production pipe for production of oil or gas from a well in an oil and/or gas reservoir, or for injection of fluids into a well in an oil and/or gas reservoir, includes a production pipe with a lower drainage pipe. The drainage pipe is divided into sections with one or more inflow restriction devices which control the flow of oil or gas from the reservoir into the drainage pipe on the basis of calculated loss of friction pressure along the drainage pipe, the calculated productivity profile of the reservoir, and the calculated inflow of gas or water.

Abstract: A method for completing a horizontal wellbore in a loosely consolidated or unconsolidated formation. To minimize collapse of the wellbore and minimize sand production while providing for greater flexibility in the placement of a sand control device in a horizontal wellbore, a slotted liner with a flexible sand control device affixed thereto is positioned into the horizontal wellbore. After positioning, the liner with sand control device attached, high permeability of openings within the liner is maintained when producing hydrocarbonaceous fluids from the formation.

Abstract: A well liner having dual concentric half screens for filtering sand and undesirables from fluids, gases, and toxic extractions. The well liner provides concentric half bodied screens of opposite orientation to provide a tortuous flow of path for the production fluids. The screens are manufactured by techniques well known in the art in the preferred embodiment. Two screen members are provided each comprising two annular portions: a screen portion and a solid pipe portion. The inner screen member is inserted in the outer screen member and both members are welded at each end. Additionally, an apertured base pipe may be provided. In the alternate embodiment, an apertured base pipe is surrounded by two full screen tubular members. A tortuous flow path is created in the alternative embodiment by the placement of shield members along a portion of the inner and outer screens. Additionally, the shields may be varied depending upon the placement of the apertures along the base pipe.

Abstract: A method of manufacturing a selective isolation screen includes steps of preparing for a tubular screen provided with spacer members and a wire on a base member, and supplying sealing material from a sealing material supply device which supplies sealing material at a location where sealing is required on the tubular screen while rotating the sealing material supply device relative to the tubular screen thereby filling the annulus between the spacer members which are adjacent to each other in the circumferential direction to form seal means. Difficulty in welding can thereby be avoided and location and state of mounting of sleeves can be visually checked.

Abstract: A prepacked well screen assembly for preventing sand from being produced with well fluids. The assembly includes a filter medium surrounded by an outer support, with the outer surface of the filter medium being fluted or otherwise shaped to have a larger outer surface area than the surface area of the outer support member surrounding the filter medium.

Abstract: The present invention provides a preperforated casing for a well bore and a method of installing a preperforated casing in a well bore. The inventive casing comprises (a) a conduit having a plurality of apertures extending through the wall thereof and (b) a liner fixed adjacent at least a portion of the interior surface of the conduit such that the liner is positioned adjacent the apertures and is operable for preventing fluid flow through the apertures. The liner is removable from the conduit by drilling. Additionally, the liner comprises a material which, upon drilling, will break up into pieces which can be readily circulated out of the well. The inventive method comprises the steps of running the inventive casing into a well bore and then drilling the liner such that the liner is broken up into pieces and the above-mentioned apertures are open for fluid flow.

Abstract: There is disclosed a reciprocating rod type downhole pump for an oil well wherein a filter on the lower end of the barrel of the pump includes a solid body of filtering media having small tortuous passageways connecting its inner and outer sides and decreasing in size from its outer to its inner side.

Abstract: An arrangement for driving out volatile impurities from a ground water with a well shaft extending to the region of the ground water to be purified, the arrangement comprises an element for producing a negative pressure in the well shaft and supplying a gas underneath a water level in the well shaft, an element for providing a plurality of capillary openings in an upper sieve wall portion of the well shaft at least in a purification region between a gas inlet and a water level in the well shaft to enhance a laminary flow of ground water with relatively high speed, the capillary openings forming a greater free throughflow surface than a remaining portion of the well shaft.

Abstract: Device combinations and methods for wellbore operations for simplifying production methods and workover operations and for production from a failed secondary zone. Using a commercially available prior art coil tubing unit, a coil tubing string is run into an already-in-place production tubing string. The coil tubing string has a commercially available prior art sand control device at the bottom, a portion of blank pipe and a commercially available prior art releasable hydraulic running and release tool ("hrart"). A commercially available prior art small washpipe is connected to the hrart. Wash fluid flows through the hrart, to the wash pipe, and then out of the washpipe thereby washing the sand control device into place in filter media at the perforated production zone. An isolation packer or packers are set between the production tubing and coil tubing string.

Abstract: A method and apparatus are provided for use on a subterranean well gravel packing conduit. The apparatus incorporates a cylindrically shaped inner tubular member having an interior wall and an exterior wall. A fluid flow passageway is defined within the interior wall of the tubular member and fluid flow passage means extends from the interior of the tubular member through the exterior wall and communicates with the fluid flow passageway. In a preferred embodiment, an outer fluid-porous means, or particulate restricting means is carried around the exterior wall of the tubular member having its interior facing the tubular member.

Abstract: Sand is filtered from an oil flow from a sand-containing oil producing formation or interval of an oil well by passing the oil flow with entrained sand through a filter assembly containing filtering media in the form of a body of juxtaposed composite particles. Each composite particle has an iron-containing core surrounded by a continuous chromium cladding, the composite particles having a size to permit passage of the oil flow through the body of the composite particles while substantially preventing flow of sand therethrough.

Abstract: A process and apparatus for removing particulate matter from fluid wells where low pH conditions or high temperature exist. The process comprises forming a cylindrical shaped retainer having one closed and one open end. Said retainer has an inner and an outer wall which join with said closed end to provide a space between said walls. An open ended fused porous refractory tube is fitted within said space. Said retainer, with the refractory tube therein, is affixed to a delivery tube. This tube is directed into a formation where said refractory tube is used to control fines or sandflow entrained in fluids obtained from said formation. Being sandwiched between said walls, the refractory tube is protected from shock and is easily removed for cleaning. Said refractory tube is chemically resistant and endures high temperatures encountered during steam-flooding or steam injection.

Abstract: A well liner having a selective isolation screen comprises an elongate base pipe having a predetermined number of openings therethrough which is surrounded by circumferentially spaced, longitudinally extending spacer bars, one or more annular cylindrical sleeves secured to the exterior of the base pipe and a continuous wire wrapped therearound to form an inner annulus isolated at predetermined vertical locations corresponding to specific well requirements of varying lengths and production formations within the wellbore. The continuous wire is wrapped over the spacer bars and sleeves in a spaced spiral configuration to provide a predetermined constant gap between the wire wrapping. The gaps in the wire wrapping are sized to stop the movement of the formation sand and allow continual flow of fluid into the wellbore. Gravel or other particulate matter may be pumped down the borehole in the outer annulus between the interior of the borehole or an outer casing and the outer surface of the wire wrapping.

Abstract: In oil and gas production installations, formation sand may pass through sand screens and enter the tubing, causing damage and increasing abrasive wear. Gravel used to prevent this often leaves gaps and lets formation sand pass through. The invention eliminates such gaps by incorporating an ordinary polished bore (11) in the sand screen (4, 7) to land and seal off the wash pipe (9). Two concentric tubes (4a, 4b) are connected to each other by a collar (17) whose inside surface is a polished bore (11) and whose outer side has supports (17a, 17b) for the tubes (4a, 4b) and the upset screens.

Abstract: A well screen filter is formed with inner and outer concentric screens defining an annular filtering space filled with filtrating medium. A lower perforated plate supporting the filtrating materials has passages allowing transit of fine particles entrained into the filter with formation fluid to a sedimentation tube preventing clogging of the filtering pack. A top perforated plate may be provided to prevent clogging of upper back areas. Openings in the outer screen extend elevationally higher than corresponding openings in the inner screen so that as the filtrating materials compact during production the inner screen openings always remain covered by the pack. A method of installing the sand control filter is also disclosed, utilizing a wash down media of glass or polymer spheres surrounding the filter to assist in stabilization of formation sand when the well is initially placed in production.

Abstract: A well screen-filter includes a pair of substantially spaced concentric screens defining an annular filtrating space therebetween, connected with perforated joint(s) closing the lower end of the filtrating space. The annular space is filled with filtrating materials (gravel or synthetic balls) as a pack and an upper joint acts as a cover cap of the annular filtrating space to seal the pack. The lower perforated joint includes holes for passage of fine particles to a sedimentation tube, preventing clogging of the pack and enabling proper functioning of the double walled screen-filter.

Abstract: A well screen-filter includes a pair of substantially spaced concentric screens defining an annular filtrating space therebetween, connected with perforated joint(s) closing the lower end of the filtrating space. The annular space is filled with filtrating materials (gravel or synthetic balls) as a pack and an upper joint acts as a cover cap of the annular filtrating space to seal the pack. The lower perforated joint includes holes for passage of fine particles to a sedimentation tube, preventing clogging of the pack and enabling proper functioning of the double walled screen-filter.

Abstract: A well screen-filter includes a pair of substantially spaced concentric screens defining an annular filtering space therebetween, connected with perforated joint(s) closing the lower end of the filtrating space. The annular space is filled with filtrating materials (gravel or synthetic balls) as a pack and an upper joint acts as a cover cap of the annular filtrating space to seal the pack. The lower perforated joint includes holes for passage of fine particles to a sedimentation tube, preventing clogging of the pack and enabling proper functioning of the double walled screen-filter.

Abstract: Well screen assembly for permitting a plurality of pipe based well screen segments in an extended length production zone to be brought into operation simultaneously uses a ported connector sub to join each pair of screen segments so that the ends of the relatively large diameter perforated pipe base supports are attached to the connector's ends. Each screen also has solid internal pipe members of much smaller diameter which are joined to a central bore in the connector. Annular spaces between the internal pipe members and the pipe base supports communicate through the connector ports and permit flow from both screens to reach the inside of the inner pipe members when downhole perforations are made in only one of the inner pipe members.

Abstract: Prepacked well screen and casing assembly for use in wells provides very substantial savings in the expense and time required to complete a well as compared to the conventional techniques of down-hole perforating and gravel packing. The assembly includes an external casing or liner member which would be provided with a large number of perforations during manufacture. A pipe base screen jacket assembly is positioned concentrically within the casing and attached to it by readily machinable upper and lower annular ring members. The hollow cylindrical annulus between the screen and casing is filled with a resin-coated gravel pack material which is cured after the fill operation to maintain its integrity. The assembly can be hung in the uncased producing zone of a new well by a liner hanger or could be placed in an existing cased well which is to be reworked by first milling away the existing casing in the production zone.

Abstract: The gas well includes a plurality of generally tubular gas extracting means which extend from the ground surface downwardly, a lower interval of which means have longitudinally extending slots in the body wall through which gas may enter while the means lower end is closed. The slotted interval resides in the gas producing ground region. The extracting means two major parts are a lower part including the perforated interval which is of relatively larger diameter, and an upper part that extends outwardly of the ground plane and which is of smaller diameter. A transition joint interrelates the two diameter extracting means parts enabling the two parts to move longitudinally with respect to each other for accommodating ground subsidence in the gas producing region.

Abstract: An improved sand shield is provided for use on the end of a string of tubing suspended in a casing in a borehole in an oil well to reduce the entrance of sand into a bottom hole pump, the sand shield being in the form of a length of tubular material surrounding a perforated mud anchor in which the bottom hole pump is situated, the produced fluid being forced to flow upwardly in the annular area between the mud anchor and sand shield to enter the pump, and including vents communicating with the upper portion of the annular area to provide for the escape of gas trapped within the sand shield.

Abstract: A screen device is provided for use in a subterranean well and is carriable within the well on a tubular conduit. The screen has an elongated outer housing with a plurality of flow passageways extending through the housing. An inner perforable cylindrical mandrel with upper and lower ends has at least one of the ends securable with a conduit member of the tubular conduit. The mandrel longitudinally extends through the interior of the housing and is secured against movement relative to the housing. A central passageway in the mandrel communicates with the tubular conduit for transmission of fluid. Prior to perforation of the mandrel, the screen device prevents fluid flow between the flow passageways and the central passageway of the mandrel. Subsequent to perforation of the mandrel, the screen device permits transmission of fluid between the flow passageways, the central passageway and the tubular conduit.

Abstract: Mounting arrangement for a bimetallic pipe base well screen which must operate at elevated temperatures includes a pair of expandable end boss rings at the ends of a cylindrical screen member. The end boss rings overlie unperforated portions of the outer surface end portions of an internal pipe member which has perforations along a portion of its length which underlie the well screen. The screen member and the end boss rings have a greater temperature coefficient of expansion than the pipe base. At room temperature, the end boss rings have a smaller inner diameter than the outer diameter of the pipe base. The boss ring portions are heated and shrunk-fit onto the pipe base to a degree that at operational temperatures they will either expand slightly out of contact with the pipe base, or at least become substantially unstressed, thus preventing damage to the screen member while also blocking out the entry of particles.

Abstract: Economical plastic well screens having good hydraulic performance can be produced by the method of the present invention wherein a sheet having a large plurality of V-shaped slots is injection molded, is roll-formed into a cylindrical shape, and then has its longitudinal edges bonded to each other. The resistance of the screen to collapse and tensile forces can be enhanced by the addition of ribs in one or two directions. Also, the sheet can be rolled in one direction or another to vary the slot direction or to permit flow from inside to outside as well as the conventional outside to inside.

Abstract: A downhole tool suction screen assembly includes a top screen assembly adapter, a lower screen assembly adapter, and a tubular screen mandrel connected between the top and lower screen assembly adapters. A cylindrical pump screen is disposed about an outer surface of the screen mandrel. A discharge passage is disposed in the screen assembly for communicating a discharge of a downhole pump with a lower end of the lower screen assembly adapter. A suction inlet passage is disposed in the screen assembly for communicating the outer surface of the screen mandrel with an intake of the downhole pump through the top screen assembly adapter.

Abstract: An erosion-resistant sand screen assembly is described for use in petroleum wells of the type in which sand tends to become entrained in the stream of petroleum entering the wellbore. The assembly is especially useful in cased holes in formations which consist of very find sand, such as have been encountered in the Gulf Coast region of the United States and off the east coast of Trinidad. The assembly uses a sleeve with an erosion-resistant wall at least one-fourth inch thick, positioned around the outside layer of wire screen. Preferably, the assembly has an outer surface of a resilient elastomeric material.