Mobil Oil Corporation

Israel J Heilweil

Tsoung Y Yan

John C Nnadi

Joseph J Dickert, Jr

Costandi A Audeh

James R White

Dennis H Hoskin

Wilton F Espenscheid

Frederick C Schwab

Gerald L Shoemaker

A process for inhibiting the formation of scale in process equipment and conduits that form because of the presence of scale forming salts present in process fluids flowing therein is provided. In this process a scale inhibiting effective amount of an inhibiting agent selected from the group consisting of polymeric sulfates, polymeric sulfonates and mixtures thereof is added to the process fluid.

Process for inhibiting scale formation

There is provided an aqueous brine fluid containing a high salt concentration and a polyvinylpyrrolidone polymer or copolymer which serves to increase the viscosity thereof, particularly at elevated temperatures of above about 300.degree. F. These fluids are particularly useful as drilling fluids for the drilling of oil and gas wells.

High temperature stable aqueous brine fluids viscosified by

A clay-thickened, water-based drilling fluid composition demonstrating enhanced stability at the elevated temperatures encountered in deep drilling oil and gas recovery operations in described. The drilling fluid composition comprises an aqueous clay dispersion and a dispersing amount of a polymer crosslinked through a polyvalent metal cation.

Controlled release dispersant for clay-thickened, water-based drilling

A process is provided wherein dissolved salts are selectively extracted from aqueous saline media by contacting the aqueous media with a solvent comprising a water insoluble organic diluent such as kerosene and a surfactant capable of effecting a preferntial transfer of solubilized salts in the aqueous media into the non-aqueous phase.

Process for selectively extracting dissolved salts from aqueous media

Various water-soluble additives, either alone or in various combinations, for use in water-based clay drilling fluids. The additives are an acrylate polymer, an acrylate propylene glycol copolymer and three structurally different sulfonate amide polymers. One of the sulfonate amide polymers is a terpolymer consisting of a random distribution of units of the formulae ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each is hydrogen, methyl, or ethyl, and X.sup.+ is a cation. A second sulfonate amide polymer is a copolymer consisting only of a random distribution of units (a) and (b). The third sulfonate amide polymer is a copolymer consisting of 2-acrylamido-2-methyl propane sulfonic acid and acrylamide. The acrylate polymer is of the formula ##STR2## while the acrylate propylene glycol copolymer is of the formula ##STR3## Drilling operations using a drilling fluid containing these compositions can be carried out at pH levels from about 8 to 11.5 and at temperatures up to about 220.degree. C. The use of the above compositions in a water-based clay drilling fluid results in a reduced fluid loss rate.

Additive systems for control of fluid loss in aqueous drilling fluids at

An aqueous brine fluid is disclosed which contains a high salt concentration and a water-soluble copolymer of acrylamidomethylpropanesulfonic acid salts which serves to increase the viscosity thereof, particularly at elevated temperatures of above about 300.degree. F. These fluids are particularly useful as fluids for drilling operations.

An aqueous brine fluid, particularly useful as a drilling fluid, and containing a high salt concentration, a vinyl sulfonate amide copolymer such as a water soluble copolymer of acrylamidomethylpropanesulfonic acid salts, and a thermal stability enhancing additive, is provided. The aqueous brine fluid is particularly useful at elevated temperatures in the range of about 150.degree.-220.degree. C.

High temperature stable aqueous brine fluids

A water-based clay drilling fluid or mud suitable for drilling at temperatures up to 200.degree. C. and pressures up to 100 psig at pH levels from 8 to 11.5, said mud or fluid containing additives which are two separate and distinct water-soluble vinyl sulfonate amide polymers. One polymer consists of a random distribution of units of the formulae ##STR1## The other polymer consists of a random distribution of units of the formula (a) and (b) as described above. In each polymer, R.sub.1 and R.sub.2 are the same or different and each is hydrogen, methyl, or ethyl, and X.sup.+ is a cation. Drilling while using this improved fluid or mud results in a reduced fluid loss rate.

Vinyl sulfonate amide copolymer and terpolymer combinations for control

There are provided wellbore treating fluids containing densifying salt dissolved in a solvent for this salt. This solvent contains at least about 50 percent by weight of a liquid non-aqueous solvent such as, e.g., N-methyl-2-pyrrolidone, such that the overall solvent has desirable properties with respect to the ability to dissolve salt, miscibility with water, melting point, boiling point, flash point and viscosity. Examples of such wellbore treating fluids include drilling, completion, packer and workover fluids.

High temperature stable fluids for wellbore treatment containing

There are provided drilling fluids containing densifying salt dissolved in a solvent for this salt. This solvent contains at least about 50 percent by weight of a liquid non-aqueous solvent such as, e.g., N-methyl-2-pyrrolidone, such that the overall solvent has desirable properties with respect to the ability to dissolve salt, miscibility with water, melting point, boiling point, flash point and viscosity.

High temperature stable drilling fluids containing non-aqueous solvents

There is provided an aqueous brine fluid having a pH of less than about 5 and containing a high salt concentration and a basic N-heterocyclic polymer or copolymer such as polyvinyl pyridine which serves to increase the viscosity of the fluid, particularly at elevated temperatures of above about 300.degree. F. These fluids are particularly useful as drilling fluids for the drilling of oil and gas wells.

Acidic high temperature stable aqueous brine fluids viscosified by basic

There is provided an aqueous brine fluid containing an N-heterocyclic organophosphorus compound which serves to increase the viscosity thereof. These viscosified brine fluids are particularly useful in drilling operations, most especially as solids-free drilling, completion, packer and workover fluids for drilling operations involving deep wells.

An improved solvent extraction process is described for the preparation of lube oil products, the improvement whereby the solvent contains an additive which facilitates phase separation and increases the yield of raffinate.

Solvent extraction production of lube oil fractions

As a new class of multifunctional additives for industrial fluids, the compounds having the following general formula: ##STR1## IN WHICH EACH X and Y represents a heterocyclic nitrogen radical and may be the same or different for each occurrence of X and Y; Z is a basic nitrogen-containing radical; n is 0 or an integer of at least 1, preferably 1 to 10; and A, B, C, and D are linked groups derived from compounds which may provide desired functions, such as detergent, antioxidant, and antiwear properties, or indirectly useful functions, such as adsorbency. At least one of A, B, C, or D is amino or anilino or is derived from an alkenylsuccinimide or an alkyl lactam or tetrahydropyrrolidine, or alkyl-substituted Mannich base, having at least 8 carbon atoms in the alkenyl or alkyl radical, or combinations of any of these. The reaction between these products and metal compounds particularly alkali and alkaline earth metal compounds provides more improved properties.

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Princeton, NJ, United States of America

Israel J Heilweil