Abstract: To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

Abstract: A triaxial test cell and pressure balanced piston therefor that includes a housing containing a vessel wherein a test specimen is located, immerged in a confining fluid. The housing includes a passage wherein the piston is installed to slide so as to move an end thereof into the vesel, which passage includes an annular area formed intermediate therealong wherein a collar portion of the piston is fitted. The piston collar portion includes a face whose surface area is equal to the area of the piston end face that travels into the vessel, and the annular area above that collar upper face is connected by an open passage to that vessel. The piston and passage include appropriate ring seals for providing a pressure seal above and below the passage annular area and that annular area is separated by a pressure seal arranged around the piston collar, with the annular area below that collar vented to atmosphere.

Abstract: A method for accelerating the freezing of sea water by two different, but related approaches. One involves the use of fluorinated or fluorochemical surfactants, other surfactants with specific activity in saline water, and the other by treatment with ice nucleation agents or the use of both. The specific application for the process is construction of improved load bearing ice structures as used in Arctic regions in supprot of hydrocarbon exploration and production activities.

Abstract: A method for accelerating construction of a load bearing ice island, formed by either sea water spraying or flooding techniques, of higher quality or in a shorter time or both than would otherwise be possible. The method involves forced refreezing of spray ice by application of a vertical stream of cold ambient air, as produced by a fan or other devices described, directly downward on the ice surface or by application of the downwardly directed air stream to an impounded mass of sea water. The specific application for the process is construction of improved load bearing structures as used in Arctic regions in support of offshore hydrocarbon exploration and production activities.

Abstract: The present invention embodies an improved method for the in situ mining of low to impermeable minerals to sweep out sections of deposits beneath the surface of the earth.

Abstract: Hollow, fine-grained ceramic proppants are less expensive and improve fracture control when compared to conventional proppants (dense alumina, mullite, bauxite, zirconia, etc.). Hollow proppants of the present invention have been fabricated by spray drying, followed by sintering in order to obtain a dense case and a hollow core. These proppants generally have high sphericity and roundness (Krumbein sphericity and roundness greater than 0.8), have diameters on average between 2250 and 125 .mu.m, depending on proppant size required, and have strength equal to or greater than that of sand. The hollow core, the size of which can be controlled, permits better fracture control in hydraulic fracturing treatments since the proppant can be transported in lower viscosity fluids. Hollow proppants produced at the same cost/weight as conventional proppants also provide for lower costs, since less weight is required to fill the same volume. The fine-grained (preferably less than 5 .mu.

Abstract: The present invention in a rotary coupling or swivel is arranged for maintaining together, respectively, stationary and rotating pipes wherethrough a fluid under pressure is passed and involves an outer stationary body with an inner body journaled therein. The two bodies are held together by positioning a number of hardened balls within complimentary grooves formed, respectively, around the stationary body inner circumference and around the inner body outer circumference, the aligned grooves forming a track or race wherein the hardened balls roll freely. The hardened balls are dropped into the grooves through a port formed through the stationary body, holding the bodies together and functioning as a roller bearing to carry high thrust loads beyond the pressure loading.

Abstract: The method of the present invention involves a two-phase process for in-situ retorting and recovery of carbonaceous material contained within typical subterranean tar sand formations, and includes formation of conventional arrays of in-seam ducts, and positioning heating devices to heat a section of the formation over a large extent thereof. The operation of the heating devices in the first phase is controlled to provide heat into the formation without burning of the carbonaceous material therein, resulting in development of a quasi-stable zone of pyrolysis about the heating duct, to thermally crack the carbonaceous material producing various organic liquid oil fractions and derived condensible vapors and non-condensible gases. The products produced thereby are then withdrawn through a suitable array of collection wells.

Abstract: The present invention involves a new method for measuring plane strain fracture toughness (K.sub.Ic) of a somewhat non-elastic material uniquely suitable for use on specimens that are smaller than have formerly been required for performing valid K.sub.Ic tests. The present invention involves selecting a short-rod specimen configuration in which the specimen material at a crack front or tip therein would be constrained during loading to a plane strain state and, from the measurement and anelastic analysis of a load-displacement curve that includes at least two unloading slopes the energy per unit crack area that is required to slowly advance a steady state crack can be determined, which data, along with measurement of the critical load when the crack passes through a known location, and considering the specimen geometry, is used to determine the fracture toughness, K.sub.Ic, of the specimen.

Abstract: The gauge of the present invention consists of a three-pronged spring clip for arrangement between the grips of a conventional grip-loading fracture specimen loading machine, which grips are inserted into the mouth of a standard slotted fracture toughness test specimen, the gauge to monitor the specimen mouth opening displacement thereof during a test for fracture toughness. The spring clip preferably is formed from a single sheet of material that is bent appropriately to produce two aligned legs or prongs with a center leg or prong there between. In operation the outside prongs are essentially stationary while the center prong is arranged to flex with respect to grip movement apart, which center movement is sensed electrically by a strain gauge secured thereto at its point of bending.

Abstract: The present disclosure concerns an active drill stabilizer assembly for arrangement in a drill string directly behind a conventional or modified drill bit that utilizes drilling fluid as a sensing and working deviation/correction energy source. In a sensing loop of the present invention, the drilling fluid passes through groups of pitch and yaw sensor outlet ports and orifices that direct the fluid against the bore-hold side wall. The flow through the orifices is proportional to the gaps between the outlet ports and the well bore side wall and grouping of the sensors provides for an "averaging effect" to the fluid flow that ignores local side wall surface irregularities and produces an instantaneous venturi throat pressure for each axis.

Abstract: The present invention in an energy conserving greenhouse involves an insulated and opaque structure whose inner walls are preferably formed, coated or colored to reflect visible light striking thereagainst onto plant surfaces therein, the structure utilizing a shuttered lense arrangement of minimum dimensions, that is open during daylight hours to pass sunlight from a focusing solar collector, that sunlight passing through an infra red trap to heat a material therein, that heat being removed for immediate heating of the structure and/or storage for later heating thereof, the remaining sunlight spectra, including the visible spectra passing therefrom and to a diffuser that directs and disperses it throughout the structure interior.

Abstract: A constant point of load application fracture specimen loading machine for applying a load between grips that engage opposite grip groove faces of a slotted specimen that preferably has as a remainder portion in that slot a "V" shaped slot root whereby, when the machine grips are moved apart, they rotate so as to apply a constant point of load application to pull the specimen apart at that slot root. The machine of the present invention is useful for measuring the fracture toughness, fatigue-crack growth resistance, or stress corrosion crack growth resistance of slotted specimens providing a unique force application system whereby sliding friction losses are minimized, and other introduced effects, such as from specimen grip machining tolerances, or the like, are largely automatically compensated for.

Abstract: The present invention relates to hydraulic prestressing nuts for setting a tensile stress in a bolt whereon the nut of the present invention is turned. The invention involves a nut body wherein an annular piston is arranged to be hydraulically extended from a bottom face thereof against a plate, head, platen, or the like, elevating the nut and extending the bolt therewith. A concentric loading ring is arranged with the nut body for turning into engagement with the place, such that when the loading ring is so extended, it provides a rigid columnar support to the annular piston. Tensile stress on the bolt is maintained by the loading ring. The nut of the present invention further involves a failsafe arrangement for providing a backup repressurization capability consisting of a second piston arrangement that can be independently pressurized at a primary seal failure, extending the primary piston therewith.

Abstract: The present invention relates to a method for measuring the fracture toughness of rock as it would exhibit in its natural down-hole setting. Practicing the method of the present invention involves internally pressurizing a rock specimen while simultaneously exerting an increasing external horizontal stress thereon, raising simultaneously the internal pressure to maintain a desired relationship of exterior to interior pressures until the specimen fractures, which pressure, in relationship to the stress intensity factor and specimen geometry, provides the specimen fracture toughness as it would exist in a down-hole situation.

Abstract: The present invention consists of a method for accurately measuring the plane strain fracture toughness of ductile and brittle materials, the method to be practiced on a specimen formed such that, when the specimen is appropriately loaded, a crack will initiate at a predetermined point or line, with such crack formed thereat being intrinsically stable such that the load executed on the specimen must be continually increased in order to further advance the crack along a predetermined path through the specimen, until, at some critical location along the predetermined crack path, the load necessary to further advance the crack reaches a maximum, thereafter decrasing as the crack advances beyond the critical location along the remainder of its predetermined path through the specimen, that critical location being essentially independent of the specimen material, it being determined by the specimen geometry alone as long as elastic plane strain conditions prevail in the specimen sufficiently close to the crack tip.

Abstract: A machine that can be used for loading of a slotted specimen for measuring the fracture toughness, fatigue crack growth resistance, or stress corrosion crack growth resistance of that specimen, the machine having a pressure bag maintained in a frame, which pressure bag can be installed within the slotted portion of the specimen and expanded to produce a desired specimen loading, the machine preferably involving a load pressure sensing device, can optionally include an arrangement for sensing volume enlargement of the specimen slot, and can also include a movable frame portion that expands with the pressure bag during inflation to discourage crimping of that pressure bag during specimen loading.

Abstract: This is an invention in a method for locating the azimuthal direction of fractures induced into an underground formation adjacent to a well bore. Practicing the method of the invention involves measurement of stresses created at or near ground surface by such fracture propagation, utilizing pressure sensitive devices making up stress meters which reflect those stress changes on standard pressure gauges. Such stress meters are preferably each placed at an optimum distance from a well bore and spaced therearound, and, when a fracture is induced in the formation around the well bore, preferably by hydraulic means, said stress meters measure surface stress changes as horizontal pressure changes, which pressure change measurements can then be used to mathematically determine the direction of the fracture.