Abstract: A polyvinyl alcohol-aldehyde gel having a high water content and low degree of crosslinking is provided which has improved stability. The gel can be used to retard the flow of water in subterranean formations encountered in hydrocarbon production. One embodiment of the invention provides a method of forming the gel in-situ in the pores of subterranean zones thereby retarding or blocking the flow of water therein.This application is a continuation application of copending Ser. No. 027,723, filed Mar. 19, 1987, now abandoned which was a divisional application of Ser. No. 693,680, filed Jan. 22, 1985, now U.S. Pat. No. 4,664,194 which was a continuation-in-part application of Serial No. 514,557, filed Jul. 18, 1982, now U.S. Pat. No. 4,498,540 which issued Feb. 12, 1985.

Abstract: A corrosion probe having in combination at least one first, at least one second, and at least one third electrode. A dielectric is positioned between the electrodes, and the dielectric has a structure defining an ionically conductive surface. An apparatus for measuring the corrosion rates of metals, or the like, in a corrosive liquid environment comprising the corrosion probe, a potentiostat electrically attached to the electrodes of the corrosion probe, and a signal generator electrically communicating with the potentiostat. The apparatus also has a voltmeter and an ammeter. A process for measuring the corrosion rates of metals in a corrosive liquid environment comprising attaching electrically the corrosion probe to a potentiostat. The corrosion probe is inserted into the corrosive liquid environment and either a predetermined known current is signaled to the potentiostat or a predetermined known difference in potential is signaled to the potentiostat.

Abstract: A corrosion probe having in combination at least one first, at least one second, and at least one third electrode. A dielectric is positioned between the electrodes, and the dielectric has a structure defining an ionically conductive surface. An apparatus for measuring the corrosion rates of metals, or the like, in a corrosive liquid environment comprising the corrosion probe, a potentiosat electrically attached to the electrodes of the corrosion probe, and a signal generator electrically communicating with the potentiostat. The apparatus also has a voltmeter and an ammeter. A process for measuring the corrosion rates of metals in a corrosive liquid environment comprising attaching electrically the corrosion probe to a potentiostat. The corrosion probe is inserted into the corrosive liquid environment and either a predetermined known current is signaled to the potentiostat or a predetermined known difference in potential is signaled to the potentiostat.

Abstract: A majority amount of a heavy hydrocarbon crude is reacted with a minor amount of brine, at supercritical temperature and pressure for the brine, for a predetermined period of time in order to upgrade and convert the heavy hydrocarbon crude into a lighter hydrocarbon crude of higher API gravity. The upgrading and conversion of a viscous heavy hydrocarbonaceous crude oil into lighter hydrocarbons is accomplished in a continuous reactor system and may be accomplished in a subterranean petroleum reservoir at supercritical temperature and pressure. The overall heat of reaction is neutral, i.e., neither exothermic nor endothermic. In order to provide the necessary temperature, heat is added to the system prior to the reaction. For an in situ application, a combustion operation may be utilized to provide the necessary temperature, and is initiated using an oxidizing gas injected through an injection well.

Abstract: A gel-forming composition is provided comprising a first substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, glutaraldehyde, and water, and which does not require a separately provided acidic catalyst to crosslink and form a gel. The gel-forming composition is useful for retarding the flow of fluids in subterranean formations. For example, a method is provided for retarding the flow of water in high permeability channels in an oil reservoir. Such method is particularly useful in waterflood operations to increase the sweep efficiency of the oil recovery process. Since these gels have very good stability at elevated temperature they can be used in reservoirs having an average in situ temperature of 80.degree. C. or higher.

Abstract: A corrosion probe having in combination at least one first, at least one second, and at least one third electrode. A dielectric is positioned between the electrodes, and the dielectric has a structure defining an ionically conductive surface. An apparatus for measuring the corrosion rates of metals, or the like, in a corrosive liquid environment comprising the corrosion probe, a potentiostat electrically attached to the electrodes of the corrosion probe, and a signal generator electrically communicating with the potentiostat. The apparatus also has a voltmeter and an ammeter. A process for measuring the corrosion rates of metals in a corrosive liquid environment comprising attaching electrically the corrosion probe to a potentiostat. The corrosion probe is inserted into the corrosive liquid environment and either a predetermined known current is signaled to the potentiostat or a predetermined known difference in potential is signaled to the potentiostat.

Abstract: A corrosion probe having in combination at least one first, at least one second, and at least one third electrode. A dielectric is positioned between the electrodes, and the dielectric has a structure defining an ionically conductive surface. An apparatus for measuring the corrosion rates of metals, or the like, in a corrosive liquid environment comprising the corrosion probe, a potentiostat electrically attached to the electrodes of the corrosion probe, and a signal generator electrically communicating with the potentiostat. The apparatus also has a voltmeter and an ammeter. A process for measuring the corrosion rates of metals in a corrosive liquid environment comprising attaching electrically the corrosion probe to a potentiostat. The corrosion probe is inserted into the corrosive liquid environment and either a predetermined known current is signaled to the potentiostat or a predetermined known difference in potential is signaled to the potentiostat.

Abstract: An acidizing composition and method for slowly dissolving siliceous material by the slow production of very low concentrations of hydrofluoric acid is provided by this invention. The continual generation of very low concentrations of hydrofluoric acid is accomplished by the hydrolysis of hexafluorotitanate-containing compounds. The acidizing composition is particularly useful and advantageous for the solubilization of siliceous clay in or adjacent the pores of subterranean hydrocarbon formations thereby increasing the permeability of said formations. Because of the very low concentration of hydrofluoric acid in the acidizing composition solubilization of siliceous clay deposits is possible at relatively large distances from the point of injection into the formation, for acidizing formations which are too sensitive for more reactive acidizing compositions, for acidizing formations containing chlorite clays, and/or for acidizing formations having an elevated temperature including formation temperatures of 125.

Abstract: An apparatus and process for expanding a tube at selective points about its circumference to join another tube. After a segment of a first tube is inserted into a second tube having an end sleeve segment with a larger diameter and wall thickness than the first tube, compression and subsequent radial expansion of elastomeric bars lodged along the generally open sides of a bushing located within the first tube end segment cause the elastomeric bars to radially expand the wall of the first tube. The wall of the first tube expands at selective points against the wall of the second tube in proximity to their respective ends, creating a selective interference fit therebetween.

Abstract: A gel-forming composition is provided comprising a first substance selected from the group consisting of a polyvinyl alcohols, polyvinyl alcohol copolymers, and mixtures thereof, a second substance selected from the group consisting of aldehydes, aldehyde generating substances, acetals, acetal generating substances, and mixtures thereof capable of crosslinking with the first substance through the formation of acetal crosslinkages, and water, and which requires contacting with a sorbed substance or brine which has sorbed substantial amounts of carbon dioxide before the gel-forming composition will form a gel. The gel-forming composition is useful for retarding the flow of carbon dioxide and other fluids in subterranean formations. For example, a method is provided for preventing the loss of carbon dioxide to nonproductive parts of an oil reservoir.

Abstract: A polyvinyl alcohol-aldehyde gel having a high water content and low degree of crosslinking is provided which has improved stability. The gel can be used to retard the flow of water in subterranean formation encountered in hydrocarbon production. One embodiment of the invention provides a method of forming the gel in-situ in the pores of subterranean zones thereby retarding or blocking the flow of water therein.

Abstract: A gel-forming composition is provided comprising a PVA based substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, an aldehyde operable for crosslinking with the PVA based substance, and water. The gel-forming composition is useful for reducing steam channeling in subterranean formations. For example, a method is provided for diverting the flow of injected steam in nonproductive steam channels in an oil reservoir during waterflood and steam cycling operations.

Abstract: A polyvinyl alcohol-aldehyde gel having a high water content and low degree of crosslinking is provided which has improved stability. The gel can be used to retard the flow of water in subterranean formations encountered in hydrocarbon production. One embodiment of the invention provides a method of forming the gel in-situ in the pores of subterranean zones thereby retarding or blocking the flow of water therein.

Abstract: A rapid setting gel-forming composition is provided comprising a first substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and aldehyde, and water, which is useful in preventing the loss of circulation fluids in well drilling, completion of workover operations. A combination process is also provided using a slower setting gel-forming composition for retarding the flow of waters or brines in high permeable non-productive channels in combination with a subsequent acidizing step for increasing the permeability of low porous structure in subterranean formations. The combination process is particularly useful in waterflood operations to increase the sweep efficiency of the oil recovery process while improving the flow oil and drive water in the productive parts of the reservoir.

Abstract: A polyvinyl alcohol-aldehyde gel having a high water content and low degree of crosslinking is provided which has improved stability. The gel can be used to retard the flow of water in subterranean formation encountered in hydrocarbon production. One embodiment of the invention provides a method of forming the gel in-situ in the pores of subterranean zones thereby retarding or blocking the flow of water therein.