Abstract: The present invention relates to a method to prepare a rheological agent comprising the polymerization of the following monomers: (a) at least one styrene-based monomer, (b) at least one (meth)acrylate-based monomer or butadiene, and (c) optionally a copolymerisable surfactant containing an optionally substituted vinyl function and moieties derived from propylene oxide and/or ethylene oxide, optionally in the presence of a non polymerisable surfactant containing moieties derived from propylene oxide and/or ethylene oxide, and optionally in the presence of another surfactant, wherein at least the copolymerisable surfactant or the non polymerisable surfactant is present during the said polymerization, as well as a rheological agent obtainable by said method, an oil-based drilling fluid containing such a rheological agent, the use of such a rheological agent as a thixotropic agent in an oil-based drilling fluid and a method of drilling using an oil-based drilling fluid containing such a rheological agent.

Abstract: The present invention relates to a method to prepare a rheological agent comprising the polymerization of the following monomers: (a) at least one styrene-based monomer, (b) at least one (meth)acrylate-based monomer or butadiene, and (c) optionally a copolymerisable surfactant containing an optionally substituted vinyl function and moieties derived from propylene oxide and/or ethylene oxide, optionally in the presence of a non polymerisable surfactant containing moieties derived from propylene oxide and/or ethylene oxide, and optionally in the presence of another surfactant, wherein at least the copolymerisable surfactant or the non polymerisable surfactant is present during the said polymerization, as well as a rheological agent obtainable by said method, an oil-based drilling fluid containing such a rheological agent, the use of such a rheological agent as a thixotropic agent in an oil-based drilling fluid and a method of drilling using an oil-based drilling fluid containing such a rheological agent.

Abstract: The present invention relates to a method to prepare a rheological agent comprising the polymerization of the following monomers: (a) at least one styrene-based monomer, (b) at least one (meth)acrylate-based monomer or butadiene, and (c) optionally a copolymerisable surfactant containing an optionally substituted vinyl function and moieties derived from propylene oxide and/or ethylene oxide, optionally in the presence of a non polymerisable surfactant containing moieties derived from propylene oxide and/or ethylene oxide, and optionally in the presence of another surfactant, wherein at least the copolymerisable surfactant or the non polymerisable surfactant is present during the said polymerization, as well as a rheological agent obtainable by said method, an oil-based drilling fluid containing such a rheological agent, the use of such a rheological agent as a thixotropic agent in an oil-based drilling fluid and a method of drilling using an oil-based drilling fluid containing such a rheological agent.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids. The chlorosulfonated a-olefin copolymers that are useful in the practice of this invention are typically chlorosulfonated ethylene/octene copolymers or chlorosulfonated ethylene/butene copolymers. The utilization of chlorosulfonated ?-olefin copolymers in oil-based drilling fluids offers (1) long service life at high operating temperatures, (2) minimal formation damage, (3) improved filtration behavior, and (4) highly effective performance at low viscosifier levels.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids. The chlorosulfonated ?-olefin copolymers that are useful in the practice of this invention are typically chlorosulfonated ethylene/octene copolymers or chlorosulfonated ethylene/butene copolymers. The chlorosulfonated ?-olefin copolymers will contain from 0.2 to 5 weight percent sulfur. The utilization of chlorosulfonated ?-olefin copolymers in oil-based drilling fluids offers (1) long service life at high operating temperatures, (2) minimal formation damage, (3) improved filtration behavior, and (4) highly effective performance at low viscosifier levels.