Abstract: A tubing release coupling which does not require rotation to effect release incorporates a collet which is retained within a groove by a collet retainer located on an axially movable piston. The piston is retained in place thereby locking the collet by a detent cantilever spring. Pressure differential between the tubing the annulus forces axial movement of the piston against the spring force of the cantilever spring effecting release of the collet. The spring force of the detent cantilever spring may be adjusted by positioning spring adjusters at a variable distance.

Abstract: An electrically conductive cable is held within the inner bore of a well tool connected to coiled tubing by a clamp which comprises a split ring having radially outwardly extending lug portions on the split ends of the ring. The lug portions are located within a longitudinally upward slot of a sleeve located within the inner bore of the well tool. Upon application of tensional force to the cable, the lugs of the split ring clamp are drawn into the taper thereby compressing the split ring in tighter engagement with the outer surface of the cable.

Abstract: A method for removing iron(III), copper(II), zinc(I) and nickel(II) from an effluent containing chelant (EDTA, DEPA, HOEDTA) comprising treating the effluent with a soluble calcium compound (e.g., Ca(OH).sub.2) CaCl.sub.2, Ca(NO.sub.3).sub.2) in a molar equivalent to the chelant in combination with a monovalent hydroxide to a pH greater than 12.4 and then adding an effective amount of a dialkyldithiocarbamate (e.g.; sodium-N,N-diethyldithiocarbamate) to precipitate the metal hydroxides and nickel dialkyldithiocarbamate. Heating the solution to about 180 F. further speeds up the removal of the nickel(II). The nickel concentration of spent chelant cleaning solution can be reduced to less than 1 ppm.

Abstract: A tertiary amine hydrochloride/persulfate breaker system as disclosed which effects complete breaks of polysaacharide-based gels or fluids in a the ambient temperature range without interfering with delayed crosslink mechanism in the fracturing fluid. The use of tertiary amine hydrochloride avoids an immediate shift in pH which would counteract means employed to effect a delayed crosslink mechanism.

Abstract: A method of packing a well, particularly an oil, gas or water well comprises injecting a particle/liquid slurry into a wellbore wherein the particles comprise particles of at least two different densities independently selected from the density range of about 0.1 to about 4.0. The at least two different density particles may be injected as blend of different density particles or in a sequential series of slugs, each slug having a single density particle suspended therein. This technique gives substantially equivalent packing efficiency throughout the annulus, perforations and perforation chambers when compared with gravel packing using specialized low to medium density materials.

Abstract: An apparatus for closing a reverse circulation passage and opening a crossover fluid passage in a gravel packing service tool which sets a well packer comprises a closure means for closing the reverse circulation passage and an opening means for opening the crossover fluid passage in response to an axial lifting force on the service tool.

Abstract: A method of inserting a well service tool for operating a coiled tubing which avoids the high and/or remote mounting of the heavy coiled tubing injector drive mechanism is disclosed. The method comprises assembling the well service tool within a closed end lubricator, mounting the lubricator or the wellhead and lowering the tool into the wellbore to a distance whereby at least a portion of the tool is adjacent the pipe rams of the wellhead. The pipe rams are then closed against the tool to effect a fluid tight seal and to hold the tool in position within the wellhead. The lubricator is then removed and the coiled tubing and injector drive mechanism are connected to the tool and wellhead, respectively. The pipe rams can then be released and normal coiled tubing operations carried out. The method offers the additional safety advantage of permitting pressure testing at each stage of the insertion process. Retrieval of the tool can be effected merely by reversing the process.

Abstract: A grapple connection for interconnecting coiled tubing with a well tool comprises first and second tapered split rings and a double-tapered intermediate split ring enclosed in a cylindrical, threaded housing.When the housing is rotated with threaded engagement of the housing to a compression ring and the well tool, the well tool and the compression ring bear against the split rings causing the tapered surfaces to press the grapples inwardly and the intermediate ring outwardly to effect a tight interconnection between the coiled tubing and the well too.

Abstract: The invention is a non-intrusive system for measuring the flow rates of insulating or conducting fluids in conduits. It results from the combination of an electromagnetic flowmeter, operating with conducting fluids, and of a triboelectric noise cross-correlation flowmeter, operating with insulating fluids. The system is equipped with a non-intrusive device for measuring fluid conductivity. The electronic signal processing unit uses the conductivity value to decide which of the two sensors is providing a signal effectively representing the fluid flow rate. The electromagnetic flowmeter may use electrodes of small cross-section in contact with the fluid or, more advantageously, it may be of the capacitive type using larger section electrodes isolated from the fluid.

Abstract: A method for breaking the fracturing fluid comprises injecting into the subterranean formation a controlled release breaker capsule including an enclosure material enveloping a breaker. The enclosure material is sufficiently permeable to at least one fluid existing in the subterranean environment or injected with the controlled release capsule such that the breaker capsule is capable of dissolving or eroding upon sufficient exposure to the fluid, thereby releasing the breaker.Using the method of the present invention, breaking of fracturing fluids is significantly improved when the temperature in the subterranean environment is from about 20.degree. C. to about 65.degree. C.

Abstract: A well penetrating a subterranean fluid producing formation can effectively be gravel packed by a process which begins with an initial low gravel loading in the carrier fluid, the gravel loading gradually being increased over the course of the gravel packing operation to provide a complete gravel pack including a gravel reservoir without formation breakdown, fluid loss, bridging and/or sand-out of the gravel pack fluid.

Abstract: A method and apparatus for treating subterranean wells includes a tool supported on a one-piece support tube which operates to raise and lower the tool in the well to a position where well treatment is required. The tool provides inflatable packers and a selector valve operable in a first position to inflate or deflate the packers, in a second position to circulate fluid to spot treatment fluid at the tool, and a third position for injecting treatment fluid into the strata isolated from the remainder of the well by the packers. The tool provides a J-lock system and a time delay dashpot which cooperate to permit an operator at the well head to selectively operate the valve between the three positions solely by adjusting the weight on the support tube at the well head.

Abstract: A method of preparing either foamed or nonfoamed fracturing fluids which maintain an at least substantially constant viscosity during the introduction of varying concentrations of proppant. The at least substantially constant viscosity fluids of the present invention provide a substantially constant friction pressure, which provides improved on-site, real-time analysis and to a better evaluation of the fracture treatment.

Abstract: Process for retarding and controlling the formation of gels or precipitates derived from aluminum and corresponding compositions, plus the corresponding applications--in particular regarding oil wells.

Abstract: The matrix treatment of a subterranean formation is adjusted in real time to minimize formation damage as indicated by the skin factor. The process comprises initial injecting an inert fluid into the formation and observing the variation in injection pressure over time. During the matrix treatment with a treatment fluid, the pressure is again observed over time and, by comparison with the pressure variation noted in the inert fluid injection phase, the skin factor is determined. The treatment parameters are then adjusted in real time to minimize the skin factor thereby minimizing formation damage.

Abstract: A crosslinker composition that can produce delayed crosslinking of an aqueous solution of a crosslinkable organic polymer. The composition comprises an organic titanium complex. The composition further contains an organic hydroxycarboxylic acid, preferably hydroxyacetic acid. The pH of the composition is preferably less than 5. The pH of the composition is further preferably such that when sufficient amount of composition is added to an aqueous polymer solution to result in delayed crosslinking of the polymer, the composition produces a pH in the resulting gel solution, preferably of between about 3 to about 4.5. Gel solutions produced using the composition are particularly useful in fracturing subterranean formations, and in particular in fracturing subterranean formations penetrated by an oil well in which fracturing process carbon dioxide and a proppant are added to the fracturing fluid.

Abstract: A method of packing a well, particularly an oil, gas or water well. A particle/liquid slurry is injected into the wellbore, the particle density to liquid density ratio of which is no greater than about 2 to 1. The particles are substantially free of surface adhesive. The particles are strained out of the slurry in the wellbore, so as to produce a packed mass of the particles adjacent the formation. The packed mass is such as to allow flow of fluids therethrough between the formation and the wellbore, while substantially preventing particulate material from the formation passing therethrough and into the wellbore. The well may be deviated. The fluid density is preferably about 0.8 to about 1.2 g/cm.sup.3.

Abstract: The invention concerns a new process for plugging and/or consolidating a permeable geological formation, notably when traversed by a borehole.The process, according to this invention, comprises the following steps: (a) insertion into the formation of an overdelayed gelling compound, composed of a gelable material and a hardener, for which the setting time is considerably longer than the suitable positioning time for the composition, in such a way that this permeates the formation over a significant distance. (b) insertion, after a mechanical or fluid plug, of a rapid-action gelling agent, which causes the instantaneous gelling of that part of the overdelayed gelling compound in the immediate neighborhood of the interface between the zone to be treated and the borehole. Thus preventing displacement of the overdelayed gelling compound toward the interior of the formation. The resultant gelling being both resistant and correctly placed.The invention application is to oil, gas, water or geothermal drillings.

Abstract: An apparatus designed for the introduction or removal of fluids from a wellbore, which apparatus comprises an elongated, extendable member and means for extending it; attached to said extendable member a conduit adapted for carrying fluid along said member; and located near an extremity of the extendable member, a means for securing said conduit to the head of a wellbore to permit fluid flow through said conduit and into or from said wellbore. Also, a method for employing the foregoing apparatus to introduce or remove from a wellbore a fluid by attaching a securing means to a wellbore head and introducing into or removing therefrom a fluid by transporting said fluid through the conduit with a fluid transporting means, said fluid flowing in either direction as may be appropriate.

Abstract: A novel test specimen configuration and modified ring test method for determining the fracture toughness, K.sub.Ic, using rock core is disclosed. The use of a truncated hollow cylindrical specimen under compressive load avoids the development of a large process zone (microcracked region) during testing, thus allowing accurate fracture toughness measurements on subsized specimens. Results using soft sandstones and Indiana limestone validate the procedure.