This invention concerns a method for enhanced oil recovery in a subterranean carbonate formation by injecting an aqueous composition comprising at least one water-soluble polymer containing acrylamidopropyltrimethylammonium chloride (APTAC).

This invention concerns a method for enhanced oil recovery in a subterranean carbonate formation by injecting an aqueous composition comprising at least one water-soluble polymer containing acrylamidopropyltrimethylammonium chloride (APTAC).

A process for recovering oil is provided. The process entails recovering an oil-water mixture from an oil-bearing formation. Next, the process entails separating oil from the oil-water mixture and producing produced water having hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. A pre-treatment process is undertaken to remove hardness and other scale-forming compounds. This entails precipitating hardness and other scale-forming compounds. After the precipitation of hardness and other scale-forming compounds, the produced water is directed to a membrane separation unit for filtering the produced water and producing a retentate having suspended solids, hardness and other scale-forming compounds, free oil and emulsified oil. The membrane separation unit also produces a permeate stream substantially free of hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. Thereafter, the permeate stream is chemically treated to enhance the recovery of oil in the oil-bearing formation. After treating the permeate stream from the membrane separation unit, the treated permeate is injected into the oil-bearing formation.

A process for recovering oil is provided. The process entails recovering an oil-water mixture from an oil-bearing formation. Next, the process entails separating oil from the oil-water mixture and producing produced water having hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. A pre-treatment process is undertaken to remove hardness and other scale-forming compounds. This entails precipitating hardness and other scale-forming compounds. After the precipitation of hardness and other scale-forming compounds, the produced water is directed to a membrane separation unit for filtering the produced water and producing a retentate having suspended solids, hardness and other scale-forming compounds, free oil and emulsified oil. The membrane separation unit also produces a permeate stream substantially free of hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. Thereafter, the permeate stream is chemically treated to enhance the recovery of oil in the oil-bearing formation. After treating the permeate stream from the membrane separation unit, the treated permeate is injected into the oil-bearing formation.

The invention relates to a novel sulfobetaine monomer and to a process for the preparation thereof, advantageously by reaction between a vinyl-amine compound and a vinyl-sulfonic acid compound, preferably in the presence of a solubilizing agent. The invention also relates to the (co)polymers obtained from this novel type of sulfobetaine monomer, and to the use thereof, for example as a flocculant, dispersing agent, thickening agent, absorbent agent or friction-reducing agent.

The invention relates to a novel sulfobetaine monomer and to a process for the preparation thereof, advantageously by reaction between a vinyl-amine compound and a vinyl-sulfonic acid compound, preferably in the presence of a solubilizing agent. The invention also relates to the (co)polymers obtained from this novel type of sulfobetaine monomer, and to the use thereof, for example as a flocculant, dispersing agent, thickening agent, absorbent agent or friction-reducing agent.

Disclosed are compositions and methods for the pressure protection of existing wells during infill drilling operations.

Disclosed are compositions and methods for the pressure protection of existing wells during infill drilling operations.

The present disclosure is directed to polyanionic surfactants, surfactant mixtures, compositions derived thereof, and uses thereof in hydrocarbon recovery. Methods of making polyanionic surfactants are also described.

The present disclosure is directed to polyanionic surfactants, surfactant mixtures, compositions derived thereof, and uses thereof in hydrocarbon recovery. Methods of making polyanionic surfactants are also described.