Abstract: Solids-free, essentially all-oil and invert emulsion wellbore fluids are employed in well drilling, completion, and workover operations. Techniques for remediating dense aromatic solvents wellbore fluids entail removal and/or dissolution of particulate matter.

Abstract: Oil-base drilling fluids containing a non-sulfonated polymer and/or a non-organophilic clay maintain desirable rheological properties at elevated temperatures.

Abstract: A solids-free, essentially all-oil wellbore fluid comprises an organic fluid having (i) a melting point less than about 20.degree. C. (about 68.degree. F.), (ii) a flash point greater than about 54.4.degree. C. (about 130.degree. F.), and (iii) a dipole moment greater than 0 debye (D) and/or an aromatic solvent having a density at about 15.6.degree. C. (60.degree. F.) of at least about 0.9 g/ml (7.5 pounds per gallon (ppg)), a flash point of greater than about 54.4.degree. C. (130.degree. F.), a solubility in water at about 25.degree. C. (77.degree. F.) of less than about 1 weight percent, a solubility in benzene at about 25.degree. C. (77.degree. F.) of at least about 80 weight percent, and a pour point of less than about 15.6.degree. C. (60.degree. F.). Generally, a salt is dissolved in the organic fluid. The wellbore fluid is employed in well drilling, completion, and work-over operations.

Abstract: A method for controlling fouling of a flashing vessel or heat-exchange surface exposed to a high-enthalpy geothermal brine tending to form silicon-containing scale. The method adds a silicon-complexing amount of fluoroborate species to the brine to form a fluid mixture that does not produce substantial amounts of the scale when the temperature of the fluid mixture is reduced. The addition does not significantly increase corrosion rates of mild steel heat-exchanger materials of construction.

Abstract: An iterative planning and monitoring method for drilling (and completing) difficult boreholes which avoids unnecessary risk or cost. The method provides multiple point value probability estimates of an indicator of drilling problems based upon a range of possible drilling variables, supplanting single point estimates. Expected drilling variables are perturbed within physically feasible bounds, and multiple estimates of the corresponding indicator values are made. The probability of each estimate is used to calculate the likelihood of an indicator of an unwanted condition. Mitigation measures are implemented if the probability of an unwanted condition exceeding a threshold value is unacceptable and the mitigated probability is reassessed. If the perturbed indicator change is not significant, the drilling variable is deleted from further analysis. Critical variables are thus quickly identified, allowing monitoring and selection of mitigation measures which are the most cost effective.

Abstract: Sulfur-containing acid is produced at a geothermal energy source from hydrogen sulfide produced as part of a geothermal process and introduced into aqueous liquid brine to lower the pH of the liquid brine. The lowered pH of the brine inhibits silica, metal sulfide and/or calcite formation on the surfaces of geothermal energy processing equipment or in subterranean formations in which the brine is injected.

Abstract: By controlling one or more properties of a gasoline fuel suitable for combustion in automobiles, the emissions of NOx, CO and/or hydrocarbons can be reduced. The preferred fuel for reducing all three such emissions has a Reid Vapor Pressure no greater than 7.5 psi (0.51 atm), essentially zero olefins, and a 50% D-86 Distillation Point greater than about 180.degree. F. (82.degree. C.) but less than 205.degree. F. (96.1.degree. C.

Abstract: Conduits having cement-containing liners for the inner and outer surfaces of metal pipes include a fibrous material, such as glass fibers, to prevent cracking and/or inhibit crack propagation.

Abstract: A non-toxic, inexpensive synthetic fluid for use in wellbore fluids (e.g., drilling fluids) is selected from the group consisting of (A) fluids having (I) a pour point greater than about -30.degree. C. (-22.degree. F.) and (II) a cetane index greater than 50, and comprising (i) at least about 95 weight percent hydrocarbons containing 11 or more carbon atoms, (ii) greater than 5 weight percent hydrocarbons containing 18 or more carbon atoms, (iii) at least about 50 weight percent isoparaffins, (iv) at least about 80 weight percent total paraffins, (v) less than 10 weight percent naphthenics, (vi) less than 0.1 weight percent aromatics, and (vii) at least 2 hydrocarbons containing a consecutive number of carbon atoms, and (B) fluids comprising (i) at least about 95 weight percent hydrocarbons containing 10 or more carbon atoms and (ii) at least about 90 weight percent n-paraffins.

Abstract: A method for cleaning oil-contaminated substrates employing a composition composed of a diluent oil, a first surfactant having a HLB value of at least 10, and a second surfactant having a higher HLB value. The difference in the HLB values of the first and second surfactants is at least 3 and a mixture of the surfactants would have a HLB value of at least 11.

Abstract: Oil-base drilling fluids containing a non-sulfonated polymer and/or a non-organophilic clay maintain desirable rheological properties at elevated temperatures.

Abstract: The emissions of nitrogen dioxide and ammonia from cooling towers in geothermal power plants are controlled by contacting the steam condensate used as make-up water for the cooling tower with a zeolite or other molecular sieve to remove ammonia and/or ammonium ions from the condensate before it is passed into the cooling tower.

Abstract: Enhanced gel properties (e.g., faster gel time, higher attainable gel strengths) are achieved by reducing the pH and/or increasing the salt of a monovalent and/or divalent cation concentration of an aqueous reaction medium in which a polymer is reacted with an organic crosslinking agent. In addition, the gelation time of an aqueous composition comprising a polymer and an organic crosslinking agent is reduced by heating the composition above about 48.9.degree. C. (120.degree. F.) prior to injecting the composition into a subterranean formation. Alternatively, the gelation time of the aqueous composition is increased by incorporating a pH increasing agent into the composition.

Abstract: Large volumes of waste water stream containing oil, greases, sometimes ferric ions, and dissolved contaminant hydrocarbons such as BTEX are rapidly treated in two stages. Initially, the oils and greases are separated, then the dissolved contaminant hydrocarbons are removed by countercurrent adsorption on powdered resinous polymeric adsorbents in an exchange zone, preferably in the absence of ferric ions. The contaminant laden adsorbents are regenerated and continuously recycled to the exchange zone.

Abstract: Selenium exists in oil refinery stripped sour water as selenocyanate and can be effectively removed using an acrylic, strong base, anion exchange column or stannous chloride. The acrylic, strong base, anion exchange column can also be employed to remove arsenic, iron, and vanadium from an aqueous fluid.

Abstract: A polymer concrete pipe liner is formed from a fluidized, but substantially waterless cement containing mixture applied to the pipe interior. The mixture contains inorganic cement particles, a liquid styrene mixture and one or more poly-olefinically unsaturated co-monomers in a greater amount than the styrene. The mixture substantially excludes acrylonitrile and acrylamide. The co-monomers are preferably selected from a group including trimethylolpropane-trimethacrylate, trimethylolpropane-methacrylate, divinyl benzene, and hexadiene. Mixing liquid and solid aggregate components forms a slurry which is transferred to a pipe interior and centrifugally cast to form the liner. The composition avoids the need for high temperature curing the toxic reactive unsaturates to co-polymerize and cross-link polystyrene.

Abstract: A multi-piece, pipe joint seal has a slidable interface between seal pieces. The slidable interface allows for slippage between pieces during pipe joint assembly and disassembly, minimizing rotational and other stresses on the seal pieces and pipe sealing surfaces which may damage or endanger the deformable seal. The slidable interface seal is especially useful for joining brittle-lined pipe sections handling harsh fluids.

Abstract: A solids-free, essentially all-oil wellbore fluid comprises (a) an organic fluid having (i) a melting point less than about 20.degree. C. (about 68.degree. F.), (ii) a flash point greater than about 54.4.degree. C. (about 130.degree. F.), and (iii) a dipole moment greater than 0 debye (D), and (b) a salt dissolved in the organic fluid. The wellbore fluid is employed in well drilling, completion, and work-over operations.

Abstract: A solidified waste is formed from a difficult-to-compact hydraulic cement slurry for use in the disposal of hazardous waste. The slurry contains inorganic non-compactible hydraulic cement particles, a concrete superplasticizer compound, water, and filler particles containing radionuclide and/or toxic contaminants. The slurry is then transferred to a storage vessel, such as a subterranean formation, to cast a stronger, denser solidified waste than a comparable solidified waste containing no superplasticizer.

Abstract: A composition exhibiting increased defoliation and growth inhibition efficacy comprises the mixture of an amide-sulfuric acid adduct and a phosphonic acid and/or phosphonic acid derivative or salt.