Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a process for controlling the permeability of the walls of the geologic formations drilled. The circulating drilling fluid includes a determined amount of gellan used as a filtrate reducer.In the process, the viscosity of the fluid is mainly controlled by polymers, such as xanthan, scleroglucan or wellan.The invention further relates to a drilling fluid including gellan.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: A water-base fluid of optimized composition for solving problems encountered during operations such as drilling, completion or workover operations in a well crossing at least one permeable geologic formation contains (i) a hydrophilic/hydrophobic polymer, (ii) an acrylamide-base polymer of hydrophobic unit, (iii) a hydrophobically modified cellulose derivative, and (iv) a polysaccharide type polymer.The fluid can be used in a process implemented in a well drilled through at least one formation having a given permeability and is for particular application to slim-hole and/or deviated drilling.

Abstract: A method for reducing retention of a polymer based displacement agent injected into a hydrocarbon containing rock matrix involves treating the matrix with an adsorbent solution containing alkali metal phosphates after the rock matrix comprising clays has been stabilized by injection of a solution containing cations obtained from KCl or NaCL salts. The presence of the cations increases the effect of the adsorbent solution.

Abstract: The invention relates to a process for cleansing solid particles impregnated with hydrocarbons. The process implements a solution comprising sophorosides. The process is particularly intended for washing cuttings impregnated with a drilling fluid containing hydrocarbons.

Abstract: In the cementing of oil wells, gas wells, or geothermal wells, wherein, under appropriate conditions, a suitable drilling fluid is injected, then optionally a slug fluid and finally a composition comprising water, a cement, at least one viscosity-enhancing additive, optionally at least one retarding agent and optionally at least one silica characterized in that the viscosity-enhancing agent is a scleroglucan solution. It applies particularly to the high temperature cementing of wells.