Abstract: Two sliding sleeves are carried in a tubular pipe assembly for controlling the opening and closing of flow passages extending through the pipe wall. The pipe assembly is placed at the lower end of a tubing string disposed in a well to regulate the flow of fluid from the string into a subsurface well formation. The first sleeve extends between upper and lower seals disposed above and below the flow passage to close the flow passages to flow. A shifting tool operated from the well surface moves the sleeve axially down through the pipe assembly to open the flow passages, leaving the upper seal exposed. The shifting tool then moves the second sleeve axially down through the pipe to cover the exposed seal. Fluid pumped through the pipe exits freely through the flow passages without first having to flow through radial flow passages in the sliding sleeve to prevent erosion of the flow passages and the sleeve structure.

Abstract: A sliding sleeve valve for controlling fluid flow between a well annulus and a string of well conduit, the valve including a slidable sleeve disposed coaxially within an outer housing, the valve being provided with a primary seal member carried by the housing for sealing engagement with the housing and the sleeve characterized in that the primary seal member, in a relaxed condition, comprises an annular, monolithic body having a first, radially outwardly facing, annularly extending seal surface and a second, radially inwardly facing, annularly extending seal surface, the second seal surface having at least one annularly extending, radially inwardly projecting rib, the rib having a radially innermost convex portion when viewed in transverse cross-section, annularly extending reliefs being formed on axially opposite sides of the rib, the seal member being made of a substantially non-elastomeric material that has sufficient memory to provide an interference seal between the seal member and the housing, and the s

Abstract: A retractable slip assembly for downhole oil tools such as packers and anchors which permits retrieval of the tool with a minimum of force and without damaging the casing or tool. The slip assembly includes a plurality of slip elements adapted to engage a setting cone which moves the slips outwardly into engagement with the casing wall. The individual slip elements travel within slip windows formed in an outer sleeve. In addition to guiding the slips, the slip windows facilitate retraction of the slip elements. In order to reduce the force necessary to release the slip assemblies, the engaging edges of the slip elements and the slip windows are provided with a cooperating angle corresponding to the slope of the setting cone and slip underside. The reduced force necessary to retract the slips allows the use of upper and lower slip assemblies in conjunction with a packer assembly.

Abstract: A bridge plug having upper and lower slips for anchoring the plug and an elastomeric packing element for sealing within a well casing. The bridge plug may be set either mechanically or through a wireline pressure setting assembly. The small outer diameter of the bridge plug allows for fast run in and the short design and material selection assures a quick drill-out. The lower cone adjacent the lower slip assembly is locked to prevent spinning of the plug during drill out. Pressure equalizing means are provided for equalizing the fluid pressure above and below the plug before drilling out the upper slips.