Abstract: The invention, in one embodiment, relates to a fluid loss control additive or composition comprising a granular starch composition and fine particulate mica, in specified proportions. The invention further comprises a fracturing fluid containing a starch composition and mica, in a specified ratio. In yet a third embodiment, the invention comprises a method of fracturing a subterranean formation penetrated by a borehole, comprising injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing starch and mica, in specified ratios, and in an amount sufficient to provide fluid loss control.

Abstract: The present invention relates to a pseudoplastic fluid composition including water, a mixed metal layered hydroxide dispersed in the water to impart preselected rheological properties to the fluid and a fluid loss additive composition including one or more of a carboxymethyl substituted vegetable starch, a carboxymethylated cellulosic compound or mixtures thereof in an amount effective to inhibit loss of fluid and with the degree of substitution being selected so that the carboxymethyl substituted compound is soluble in the fluid at the concentration of use without materially adversely affecting the rheological properties of the fluid and so that the fluid is resistant to fermentation. The improved composition includes a crosslinked carboxymethylated vegetable starch which has a degree of substitution in the broad range from about 0.3 to about 0.8 and in a narrower range of about 0.4 to about 0.

Abstract: The crosslinking of galactomannan gum fracturing fluids by borate ion is delayed for high-temperature applications by encapsulating the boron with a polymer coating. The crosslink-delay time is further adjusted by varying the concentration of an organic polyol. The polyol also acts as a stabilizer for the crosslinked fluid at elevated temperatures. Low pumping friction pressures are achieved by the delay in the crosslinking with the boron available at high temperatures to add high-temperature stability to the fracturing fluid at temperatures ranging up to about 350.degree. F.

Abstract: There is disclosed a biodegradable wellbore fluid having a continuous oil phase comprising an n-alk-1-ene having from 12 to 20 carbon atoms or a linear polyunsaturated olefin having one of the double bonds in the 1-position and having from 12 to 22 carbon atoms, or a mixture thereof.

Abstract: The invention relates to a new, chemically crosslinked PVA. Its application is that of a fluid loss control agent in fluids used in the oil industry, in particular cement slurries, separating fluids, or "spacers", and drilling muds. Its advantages are that it does not delay the setting of the cement, that it has high temperature properties that are relatively insensitive to external conditions.

Abstract: This invention concerns a device for continuously injecting liquid additives into a fluid.The device includes a jet eductors system for prediluting the additives.Applications in the oil and related industries, the building industry and similar. FIG.

Abstract: A reinforcing slat for use in an inflatable packer which is elongate and curved about its longitudinal axis and comprises perforations in the part thereof which enters the end portion and which bends around the end portion on inflation of the packer. The perforations serve to reduce the bending stiffness of the slat in the portion likely to suffer permantent deformation on inflation of the packer.

Abstract: Fractures are initiated or extended within an earth formation from a well which includes a tubing string extending to a wellbore space adjacent the fracture zone from a conventional wellhead. Carbon dioxide, nitrogen or a similar highly expansible fluid is pumped into the wellbore space and/or at least a portion of the tubing string at a pressure greater than the fluid critical pressure and greater than the fracture initiation or extension pressure required in the formation zone. A perforating gun is fired or a shear disk is actuated to release the expansible fluid to flow into the formation at an initial velocity and kinetic energy which substantially exceeds that which is obtained with water or similar conventional fracturing fluids so as to initiate or extend hydraulic fractures with a minimum radius of curvature with respect to the wellbore.

Abstract: An inflatable packer apparatus for use in a well bore has pre-formed metal stress rings surrounding the respective opposite end portions of the packer element. The stress rings are machined to initially have conical outer surfaces, and then are outwardly stressed beyond their yield strengths to obtain plastic deformation such that such outer surfaces are generally cylindrical so that the packer element can be inflated to higher pressures.

Abstract: An inflatable packer for use in a well includes a tubular mandrel, an inner elastomer sleeve on the mandrel, armor surrounding the inner sleeve, and an outer elastomer sleeve member that covers at least a portion of the armor. Stress rings are mounted on end portions of the armor are made from a metal plate which has been highly cold-worked in both its longitudinal and transverse directions to provide optimum strength characteristics against stresses imposed thereon when the packer is inflated.

Abstract: Bladder retention for an inflatable packer includes a tubular base and a retainer member. Retainer teeth are provided on both the tubular base and the retainer member to retain the bladder against the axial loads of inflation. Separate sealing ribs are provided on at least one of the tubular base and retainer member which positively engage a portion of the bladder which is not subjected to longitudinal stresses due to its location outwardly of the retainer teeth. Additionally, an elastomeric o-ring seal is provided between the retainer member and the tubular base thereby blocking the application of pressure forces tending to disengage the elastomeric bladder from its retention assembly.

Abstract: The strength of slats attached to an inflatable packer assembly by welding is increased by forming the slats of an age-hardening materials, welding the slats to the inflatable packer assembly in an annealed condition followed by age-hardening of the welded slats. A slat structure having much greater strength than welded cold-worked material is realized. Final assembly includes the steps of sliding an overlying sleeve over the end fitting, the weld and a portion of the slats and engaging threads on the interior of the sleeve with external threads on the end fitting. The sleeve can thereby be unaffected by the heat treatment steps.

Abstract: The strength of slats attached to an inflatable packer assembly by welding is increased by forming the slats of an age-hardening materials, welding the slats to the inflatable packer assembly in an annealed condition followed by age-hardening of the welded slats. A slat structure having much greater strength than welded cold-worked material is realized.

Abstract: A straddle inflatable packer system includes upper and lower packer assemblies each having an inner elastomer sleeve surrounded by expansible armor members. For well treating operations, the upper packer includes an external elastomer sleeve which covers a lower portion of its armor members, and the lower packer has an external elastomer sleeve that covers an upper portion of its armor members, so that the external sleeves are located adjacent to the higher pressures of injected fluids. For well testing operations, the locations of the external packer sleeves are reversed so that again these sleeves are adjacent the higher well bore pressures during the test.

Abstract: An inflatable packer apparatus having an inner elastomer sleeve covered by armor such as overlapped, longitudinal slats that extend between upper and lower collars. The end portions of such slats pass through stress rings having outwardly flared nose portions, and thin protector rings mounted inside the nose portions are employed to distribute very localized contact loads form the edge of the slats to the stress rings to prevent the formation of cracks in such rings. The apparatus further includes an elastomeric sleeve member which is expanded into sealing contact with a well bore wall by fluid pressure applied to the inside of the inner elastomeric sleeve member.

Abstract: A well treating tool string run on coiled tubing and having packers to isolate a zone to be treated in response to operation of a selector valve, pressure and temperature transducers in the tool string and a telemetry system which samples the measurements made by the transducers, an electrical conductor cable extending from the telemetry system up to the surface through the coiled tubing and to the inner end thereof on its storage reel, and a surface telemetry, data processing and display system that sends and receives encoded signals to and from the downhole telemetry system from which temperature and pressure values can be read out on the surface display in real time as the treating operation proceeds.

Abstract: The addition of fibrous materials in intimate mixture with particulates for fracturing and gravel packing decreases or eliminates the flowback of proppant and/or formation fines while stabilizing the sand pack and lowering the demand for high polymer loadings in the placement fluids. Preferred fibers include glass, aramide, nylon and other natural and synthetic organic and inorganic fibers and metal filaments.

Abstract: Preferential disconnection of a valve-actuating subassembly from a temporary abandonment safety valve and packer assembly is provided by stops which limit relative rotation between the valve-actuating subassembly within the valve along with a locking collar associated with the interconnection between the safety valve and the packer assembly so that high torque associated with rotational movement of a drill string in a highly deviated hole effects the release of the proper portion of the assembly without danger of undesirable release of other interconnections.

Abstract: In accordance with an illustrative embodiment of the present invention, a circulating valve for use in sand control and related well operations includes a mandrel that can be rotated in a housing after a weight-responsive clutch is released. As the mandrel is rotated to the right, a reverse lead groove system engaged by a pawl causes a valve sleeve element to shuttle down and up between positions closing and opening a flow path between the annulus above a packer and a zone in the well below the packer.

Abstract: Where on the valve seating surfaces due to the high pressure pumping of abrasive slurry through an in-line valve is greatly reduced by providing first and second valve seating surfaces which are engaged, respectively by first metal and first elastomeric closure surfaces and second metal and elastomeric closure surfaces located on an annular valve closure means. Pumping efficiency is maintained by providing for high velocity sweep in an annular space between the annular valve closure means and the cylinder in which it rides.