Abstract: A water-based fluid, containing: a non-ionic surfactant, which is stable in a temperature range from 10 to 90° C. and soluble in water; and a salt, wherein the non-ionic surfactant contains an alkyl polyglucoside selected from the group consisting of a C8 alkyl polyglucoside, a C10 alkyl polyglucoside, and mixtures thereof, and the salt is present, and is present in an amount up to 60%. In addition, a process for preventing the formation of a W/O inverse emulsion or resolving a W/O inverse emulsion that has already formed in an oil well in which an oil-based mud has been employed by injecting the water-based fluid into the oil well.

Abstract: The invention relates to a water-based fluid for applications in the oil field, comprising non-ionic surfactants, stable at temperatures ranging from 10 to 90° C., having an HLB ranging from 8 to 20 and soluble in water, with a saline content ranging from 0 to 60% by weight, and possibly salts. The fluid can be conveniently used as completion fluid for preventing the formation of inverse W/O emulsions or as a remedial fluid for resolving emulsions already formed in oil wells in which oil-based mud has been used.

Abstract: Process for the solubilization of polymeric material deposited on a porous medium, which comprises putting said polymeric material in contact with an aqueous composition comprising: (a) a catalyst selected from: (a1) a complex having general formula (I), Fe++(L)n(Y)s, L being a binder selected from those having general formula (II), wherein X?CH, N, (a2) a hydrosoluble cobalt2+ salt, preferably cobalt acetate; (b) an oxidizing agent selected from: (b1) hydrogen peroxide, (b2) MHSO5, wherein M is an alkaline metal, preferably potassium; with the constraint that the catalyst (a1) can only be used in the presence of the oxidizing agent (b1) and the catalyst (a2) can only be used in the presence of the catalyst (b2).

Abstract: The invention relates to a process for the solubilization of material containing scleroglucan and/or xanthan gum which comprises putting the above material in contact with an aqueous solution comprising an enzyme selected from a cellulase from Trichoderma reesei and/or a glucosidase from Aspergillus Niger.

Abstract: Process for the production of sulfur, obtained in pure form, and possibly easily disposable even at ambient temperature, starting from hydrogen sulphide contained in natural gas, which includes: a) oxidizing a portion of hydrogen sulphide to sulfur dioxide; b) dissolving in water the sulfur dioxide obtained in step (a); c) carrying out the reaction (I): 2H2S+SO2?3S+2H2O (I) making the remaining hydrogen sulphide to react with the solution prepared in step (b); and d) using the thus obtained sulfur suspension for the production sulfur or, alternatively, to use it for the disposal of the sulfur itself in a site reserved for such purpose.

Abstract: Process for the production of sulfur, obtained in pure form, and possibly easily disposable even at ambient tem-perature, starting from hydrogen sulphide contained in natural gas, which includes: a) oxidizing a portion of hydrogen sulphide to sulfur dioxide; b) dissolving in water the sulfur dioxide obtained in step (a); c) carrying out the reaction (I): 2H2S+SO2?3S+2H20 (I) making the remaining hydrogen sulphide to react with the solution prepared in step (b); and d) using the thus obtained sulfur suspension for the production sulfur or, alternatively, to use it for the disposal of the sulfur itself in a site reserved for such purpose.

Abstract: Process for reducing the adsorption of hydrosoluble polymers onto rock matrix, which comprises putting the rock matrix in contact with an aqueous solution of polymers containing sacrificial agents, preferably selected from ionic and non-ionic oligomeric surface-active agents. In the preferred embodiment the surface-active agents are non-ionic.

Abstract: Water-based drilling fluid comprising: (a) water, (b) at least one biopolymer of the polysaccharide type, (c) at least one filtrate reducer selected from starches with different cross-linking degrees in presence of cellulose microfibers, (d) optionally a hydrosoluble polymeric surface-active agent having an HLB from 10 to 16, preferably from 11 to 14.

Abstract: Block copolyethers having general formula (I):RX--(CH.sub.2 --CHR.sub.1 --O--).sub.x --(--CH.sub.2 CHR.sub.2 --O--).sub.y --(--CH.sub.2 --CHR.sub.3 --O--).sub.z --R.sub.4wherein:R is selected from H, alkyl, alkylaryl;X is selected from O, S and N;R.sub.1, R.sub.2 and R.sub.3 are selected from H, CH.sub.3, and C.sub.2 -C.sub.10 alkyl radicals;R.sub.4 is selected from H, alkyl, acyl;x,y,z represent the number of ether units and are integers which have such values that the molecular weight of the compound having general formula (I) is between 600 and 4000, and in addition (x+z)/y is between 1.5 and 5.0; with the proviso that:a) either R.sub.1 and R.sub.3 are selected from H and CH.sub.3, in which case R.sub.2 is selected from C.sub.2 to C.sub.10 alkyl radicals,b) or R.sub.1 and R.sub.3 are selected from C.sub.2 -C.sub.10 alkyl radicals, in which case R.sub.2 is selected from H and CH.sub.3.

Abstract: Water insoluble polymers containing hydrophilic pendant moieties ending with a chelating group are disclosed. The polymers are useful in the purification of water polluted by heavy metals such as mercury and lead. The polymers have the general formula P--(--(--O--R).sub.n --(NH--Q).sub.p --F).sub.m where P is a polymeric matrix capable of reacting with a polyalkylene glycol or an alkylene oxide having such a structure and molecular weight as to be insoluble in water; R is either --CH.sub.2 CH.sub.2 -- or mixtures of --CH.sub.2 CH.sub.2 -- and --CH.sub.2 CH(CH.sub.3)--, with the molar ratio of both units in the mixture being at least 3:1; n is 3 to 50; m is a numeral such that the % by weight of all of the --(--(--O--R--).sub.n (NH--Q).sub.p --F hydrophilic chains is higher than 1% by weight of the total weight of (I); Q is a C.sub.2 -C.sub.