US 5,465,792 A · Method of controlling production of excess water in oil and gas wells

Abstract

The production of excessive water in oil and gas wells and other subterranean formations is reduced by introducing a hydrocarbon fluid containing dispersed superabsorbing particles formed using invert emulsion polymerization techniques wherein the superabsorbing particles are formed from hydratable polymers which are cross-linked so that they are insoluble in water. By introducing these superabsorbing particles into fluid passages of the formation, the water producing zones can be selectively blocked off by allowing the superabsorbing particles to swell with the absorption of water within the aqueous fluid containing fluid passages, while the superabsorbing particles remain small and unswollen in the hydrocarbon conducting fluid passages. Thus, the ability of fluids to flow through the aqueous fluid containing fluid passages is selectively reduced resulting in the reduced production of aqueous fluids while maintaining production of hydrocarbons.

Claims36

Dependent claims

A method of selectively reducing production of aqueous fluids from a reservoir within subterranean formations having low permeabilities, the method comprising the steps of:

introducing a non-aqueous, hydrocarbon fluid containing discrete unswollen, submicron water absorbing particles which are dispersed throughout the hydrocarbon fluid into pore channels of the formation, at least some of the pore channels being aqueous fluid conducting pore channels, the absence of aqueous fluid within the hydrocarbon fluid serving to retain the particles in an unswollen state, and wherein each particle consists essentially of hydratable polymers which are cross-linked so that the polymers are insoluble in water;
and
allowing the particles to absorb water within the aqueous fluid conducting pore channels so that the particles swell within the aqueous fluid conducting pore channels and restrict the flow of fluids through the aqueous fluid conducting pore channels.

A method of selectively reducing production of aqueous fluids within hydrocarbon bearing subterranean formations in oil and gas wells, the method comprising the steps of:

preparing an aqueous solution of polymerizable hydrophilic monomers and cross-linking monomers;
mixing the aqueous solution with an immiscible liquid so that an emulsion is formed with the aqueous solution being dispersed within the immiscible liquid as discrete submicron micelles;
polymerizing the monomers within the submicron micelles so that the monomers form hydratable polymers which are cross-linked so that the hydratable polymers form discrete submicron, water absorbing particles that are insoluble in water;
diluting the emulsion in a non-aqueous, hydrocarbon carrier fluid, the absence of aqueous fluid within the hydrocarbon carrier fluid serving to retain the particles in an unswollen state;
introducing the hydrocarbon carrier fluid and the emulsion with the water absorbing particles into fluid passages of the formation, wherein some of the fluid passages are aqueous fluid conducting passages and some are hydrocarbon fluid conducting passages;
and
allowing the particles within the aqueous fluid conducting passages to absorb water and swell within the aqueous fluid conducting passages while remaining unswollen in the hydrocarbon fluid conducting passages so that the flow of aqueous fluid through the aqueous fluid conducting passages is reduced.

4 more elements

A method of selectively reducing production of aqueous fluids within hydrocarbon bearing subterranean formations in oil and gas wells, the method comprising the steps of:

preparing an aqueous solution of polymerizable hydrophilic monomers;
mixing the aqueous solution with an immiscible liquid so that an emulsion is formed with the aqueous solution being dispersed within the immiscible liquid as discrete submicron micelles;
polymerizing the hydrophilic monomers within the submicron micelles so that the monomers form discrete submicron, hydratable polymers particles;
surface cross-linking the polymer particles within the emulsion to form discrete submicron, water absorbing particles that are insoluble in water by adding a surface cross-linking agent which is dispersed within the immiscible liquid;
diluting the emulsion in a non-aqueous, hydrocarbon carrier fluid, the absence of aqueous fluid within the hydrocarbon fluid serving to retain the particles in an unswollen state;
introducing the non-aqueous, hydrocarbon carrier fluid and emulsion with the water absorbing particles into fluid passages of the formation, wherein some of the fluid passages are aqueous fluid conducting passages and some are hydrocarbon fluid conducting passages;
and
allowing the particles within the aqueous fluid conducting passages to absorb water and swell within the aqueous fluid conducting passages while remaining unswollen in the hydrocarbon fluid conducting passages so that the flow of aqueous fluid through the aqueous fluid conducting passages is reduced.

5 more elements

Dependencies are inferred from the claim text.

Method of controlling production of excess water in oil and gas wells

Life of this patent

Method of controlling production of excess water in oil and gas wells

Life of this patent

Abstract

Claims36