Abstract: A method of constructing a borehole drilled with a drilling apparatus (16), the method comprises: connecting a flexible tubular liner sleeve (22) around the outside of the drilling apparatus and connecting the sleeve around an upper opening of the borehole so as to pass into the borehole; progressively extending the sleeve into the borehole as drilling progresses while maintaining connection to the drilling apparatus and borehole opening; at a predetermined point in the drilling, expanding the sleeve so as to contact the borehole wall; and setting the sleeve so as to be fixed to the borehole wall after expansion. Apparatus for use in such a method comprises: a flexible, expandable sleeve (22); a first connector for connecting the sleeve around the outside of a drilling assembly; and a second connector for connecting the sleeve around the opening of the borehole; wherein the sleeve is arranged to extend through the borehole between the connectors as drilling progresses.

Abstract: A method of constructing a well comprising a borehole drilled through underground formations, comprises: positioning at least one device on the outside of the tubular string (e.g. a drill string or casing string), the device being operable to move between first and second configurations; positioning a tubular string in the borehole with the device positioned in the annular space between the tubular string and the borehole wall in its first configuration so as to interact with the tubular string and the borehole while allowing borehole fluid to flow along the annular space and around the device; and operating the device so as to move it from its first configuration to expand into its second configuration in which it substantially fills at least part of the annular space so as to inhibit flow of fluids along the borehole in the space.

Abstract: The invention concerns a system or a method for maintaining zonal isolation in a wellbore. According to the invention, the system comprises, at a specific location along said wellbore, a sealing element, said sealing element being able to deform both during and after placement and is maintained after placement under compression through a pressurizing fluid or by confinement in a volume.

Abstract: A method of constructing a borehole drilled with a drilling apparatus (16), the method comprises: connecting a flexible tubular liner sleeve (22) around the outside of the drilling apparatus and connecting the sleeve around an upper opening of the borehole so as to pass into the borehole; progressively extending the sleeve into the borehole as drilling progresses while maintaining connection to the drilling apparatus and borehole opening; at a predetermined point in the drilling, expanding the sleeve so as to contact the borehole wall; and setting the sleeve so as to be fixed to the borehole wall after expansion. Apparatus for use in such a method comprises: a flexible, expandable sleeve (22); a first connector for connecting the sleeve around the outside of a drilling assembly; and a second connector for connecting the sleeve around the opening of the borehole; wherein the sleeve is arranged to extend through the borehole between the connectors as drilling progresses.

Abstract: A method of constructing a well comprising a borehole drilled through underground formations, comprises: positioning at least one device on the outside of the tubular string (e.g. a drill string or casing string), the device being operable to move between first and second configurations; positioning a tubular string in the borehole with the device positioned in the annular space between the tubular string and the borehole wall in its first configuration so as to interact with the tubular string and the borehole while allowing borehole fluid to flow along the annular space and around the device; and operating the device so as to move it from its first configuration to expand into its second configuration in which it substantially fills at least part of the annular space so as to inhibit flow of fluids along the borehole in the space.

Abstract: The invention concerns a system or a method for maintaining zonal isolation in a wellbore. According to the invention, the system comprises, at a specific location along said wellbore, a sealing element, said sealing element being able to deform both during and after placement and is maintained after placement under compression through a pressurising fluid or by confinement in a volume.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity of not less than 10 &mgr;S m−1 at 1 kHz comprises a polar organic liquid (POL) which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cm−3)1/2. Oils or other organic liquids (OL) known to be suitable as the continuous liquid phase of wellbore fluids, may be used in admixture with POL component. Certain inorganic salts, organic bases, quaternary ammonium salts or hydroxides (the dissolved component, DC), display sufficient solubility (and current carrying abilities) in POL, OL or in mixtures of liquid (POL) and liquid (OL) to further improve the electrical conductivity of the mixture. The wellbore fluid can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

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 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.