Abstract: The gelation of a gelable composition is delayed by using, inter alia, a crosslinking rate retardant selected from the group consisting of epoxides, ethers, and mixtures thereof.

Abstract: A wellbore fluid (e.g., a drilling, completion, packer, or fracturing fluid) comprises (a) at least one additive selected from the group consisting of emulsifiers, wetting agents, viscosifiers, weighting agents, fluid loss control agents, proppants for use in hydraulically fracturing subterranean formations, and particulate agents for use in forming a gravel pack; and (b) a non-toxic white mineral oil having (i) an API gravity at 15.6.degree. C. (60.degree. F.) greater than 35, (ii) a content of compounds containing 14 or more carbon atoms of at least about 95 weight percent, and (iii) a pour point of at least about -30.degree. C. (-22.degree. F.).

Abstract: Aqueous thiocarbonate solutions are stabilized by the addition of base, sulfide and/or polysulfide, and the stability and safety of the more concentrated solutions containing 1 weight percent or more equivalent CS.sub.2 as a thiocarbonate are achieved as reflected by significant reduction of CS.sub.2 partial pressure in such solutions. Also, deposit formation in irrigation systems delivering such thiocarbonates, such as drip emitters and sprinkler heads, is reduced or eliminated with minor amounts of sodium hexametaphosphate.

Abstract: A fracturing fluid comprises (a) a carrier, (b) a nucleating agent capable of reducing the concentration of scale-forming ingredients and/or natural occurring radioactive materials (NORMs) present in an aqueous subterranean fluid, and optionally (c) an ingredient selected from the group consisting of proppants, friction-reducing additives, fluid-loss-control additives, gelling agents, bactericides, and scale stabilizers. The fracturing fluid is employed in hydraulic fracturing procedures to, among other things, reduce the concentration of the scale-forming ingredients and/or NORMs present in produced aqueous subterranean fluids.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Geothermal brine and other platinum-containing solutions are passed through a carbon-containing zone to recover platinum from the aqueous medium.

Abstract: Aqueous thiocarbonate solutions are stabilized by the addition of base, sulfide and/or polysulfide, and the stability and safety of the more concentrated solutions containing 1 weight percent or more equivalent CS.sub.2 as a thiocarbonate are achieved as reflected by significant reduction of CS.sub.2 partial pressure in such solutions. The stabilized thiocarbonate solutions are employed to control pests in soil.

Abstract: The addition of a nucleating or coalescing agent (e.g., urea) to liquid ammonia reduces the size and persistence of a deadly, fog-like cloud of ammonia droplets that tend to form when liquid ammonia is accidentally released to the atmosphere. In addition, high purity ammonia is obtained by evaporating ammonia from the ammonia- and nucleating agent-containing composition.

Abstract: Gels containing gas precursors and/or pathways are used to selectively reduce the flow of aqueous fluids with respect to the flow of nonaqueous fluids to enhance the recovery of the nonaqueous fluids from subterranean formations. The gels, while stable at reservoir conditions, are also readily degraded by gel degrading agents such as acids and therefore are also employed as fail-safe gels in subterranean gel treatments. In another embodiment, selective permeability is restored to a previously treated well by injecting a gas into the previous treated portions of the subterranean formation to displace any aqueous fluid obstructing the passage of the nonaqueous fluid through the polymer-coated pores or gel.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Aqueous thiocarbonate solutions are stabilized by the addition of base, sulfide and/or polysulfide, and the stability and safety of the more concentrated solutions containing 1 weight percent or more equivalent CS.sub.2 as a thiocarbonate are achieved as reflected by significant reduction of CS.sub.2 partial pressure in such solutions.

Abstract: Oil production from a fractured, oil-bearing subterranean formation is enhanced by sequentially injecting (i) a wettability reversal agent-containing fluid and (ii) an overflush fluid through a well and into the formation. The well is then place into production after allowing a sufficient period of time for (a) the matrix face of the formation to change from preferentially oil wet to preferentially water wet and (b) a displacing fluid (e.g., hot water, steam) to imbibe into the fractured matrix and displace the oil from the matrix into the fracture cracks.

Abstract: Organic tracers are employed to monitor the movement of subterranean fluids. These organic tracers are (a) stable at elevated temperatures, (b) capable of being detected at low concentrations, and/or (c) not adversely affected by the make-up of at least one subterranean formation. In addition, a plurality of these tracers can be measured by a single analytical technique.

Abstract: Gels stable in a subterranean formation at a temperature greater than about 175.degree. F. are formed using, inter alia, a stabilizing agent (e.g., a buffer having a buffering capacity at a pH of at least about 8 and/or a chelating agent).

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Compositions and methods for vegetation control comprise synergistic combinations of a thiazol-urea abscission agent and an adduct formed by the reaction of sulfuric acid with an amide. The synergistic combinations are particularly useful for the defoliation of cotton.

Abstract: Drill cuttings are cleaned of oil-based drilling mud and oil using a cleansing agent, such as a C6-C10 carboxylic acid, that is preferentially oil soluble at one pH and preferentially water soluble at another pH. The oily cuttings are treated with the carboxylic acid and then washed with an aqueous, alkaline washing solution, which converts the carboxylic acid to its water soluble salt and, with vigorous agitation, lifts most of the oil from the cuttings. In other embodiments, the process is used for cleaning oil-contaminated soil, sand, and gravel, and for separating the oils from the solids in oily sludges.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Visible gels are formed by mixing an inorganic crosslinking agent with a low viscosity aqueous solution having a low polyacrylamide content. The visible gels are employed to reduce the water/hydrocarbon permeability ratio of subterranean formations.

Abstract: Compositions and methods for vegetation control comprise synergistic combinations of a thiazol-urea abscission agent and an adduct formed by the reaction of sulfuric acid with an amide. The synergistic combinations are particularly useful for the defoliation of cotton.