Abstract: Conductivity damage is decreased in fracturing a high temperature (greater than 200.degree. F.) well by employing a first fracturing fluid which is substantially stable at the bottom hole static temperature and pumping a second fracturing fluid behind the first fracturing fluid which is less stable at bottom hole static temperature than the first-pumped fracturing 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 composition and method for inhibiting corrosion of iron and steel in the presence of aqueous acid, especially concentrated hydrochloric acid comprising at least 5% by weight HCl, comprising an effective corrosion inhibiting amount of an alkenylphenone having the following structure: ##STR1## wherein R.sub.1 may be unsubstituted or inertly substituted aryl of 6 to about 10 carbons, and R.sub.2 and R.sub.3 may be the same or different and each may be hydrogen, halogen, or inertly substituted aliphatic of about 3 to about 12 carbons, and R.sub.2 may also be alkanol, ether, or unsubstituted or inertly substituted aryl of 6 to about 10 carbons, provided that the total number of carbons in said alkenylphenone does not exceed 16, and preferably including a surfactant, and a process of using this composition.

Abstract: The present invention relates to a composition for cementing, containing a small amount of NaCl and from 35 to 150 l/t of sodium silicate. A cement-salt bond having good characteristics such as rheology, fluid loss, etc. . . . is obtained.

Abstract: An apparatus for production logging of a well utilizing artificial lift in a wellbore comprises coiled tubing extending into the wellbore, the coiled tubing having gas injector means provided on its remote end and including means for electrical communication from the surface to the injector means; production logging tool means located within the wellbore at a distance so as to separate the logging tool from the injector means and connector means interconnecting the logging tool and the injector means for maintaining a fixed separation between the logging tool and the injector means and for effecting electrical communication from the production logging tool to the electrical communication means located within the injector means.

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: Device to permanently link a metal joining piece and a composite material tube, to a tube subjected to static pressure up to 150 MPa. The assembly consists of a metal part constituting a sealing (8) and joining (7) piece with a collar (2), onto which the composite material (1) is attached. A tubular anti-abrasion and anti-corrosion (6) sleeve, flush-mounted in the metal joining piece and protected by a ring (9) at its end ensures total isolation of the composite/metal joint from corrosive fluids which may be flowing through the tube. In particular, the application of the device to oil industry sensors.

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: 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: 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 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 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: A packer and service tool assembly for oil or gas well preparation includes a disengageable coupling mechanism which permits the tool to be screwed into and out of the packer and which can be hydraulically disengaged so that the tool can be removed without applying torque to the tool or workstring. A releasable ratchet mechanism is also provided in the packer for trapping the setting loads when the packer is set in the casing. The ratchet mechanism is releasable by pulling up a housing portion which cammingly engages collapsible ratchet fingers thereby disengaging the ratchet finger trapping teeth from a stationary ratchet ring.

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: There is disclosed a method and additive to be employed in said method whereby the fouling of metal surfaces with copper deposits resulting from acid cleaning of copper alloy surfaces, be they all of the same metallurgy or merely elements with in the overall system is markedly reduced by adding to the rinse or flush formulations commonly employed following an acid treatment, a chelating agent for copper, and, subsequently adding a copper corrosion inhibitor to the conventional neutralization fluid.