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AssigneeExxon Research & Engineering Co.
InventorsEvelyn N. Drake, Peter Calcavecchio
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A process for plugging a porous formation in a well bore which comprises pumping a shear-thickening composition into drill pipe in the well under conditions of low shear to the point desired to be plugged at which point the composition is forced through the orifices of a drill bit at the end of the drill pipe and subjected to high shear of at least about 1,000 sec..sup.-1 which forms a paste in the well bore which plugs the porous formation. The shear-thickening composition comprises a water-in-oil emulsion having granular bentonite dispersed in the continuous oily phase, wherein the oily phase has a polyamine derivative surfactant dissolved therein, and the aqueous phase comprises an aqueous solution of a polyacrylamide and a polycarboxylic acid. This process may be used for plugging wells having depths in excess of 8,000 feet.
A process for plugging a porous earth formation which comprises contacting said formation with a shear-thickening composition which comprises a water-in-oil emulsion having particles of hydratable, water-expandable clay dispersed in the continuous oily phase thereof said oily phase having a polyamine derivative surfactant dissolved therein and said dispersed aqueous phase of said emulsion comprising an aqueous solution of a polycarboxylic acid and a polyacrylamide, said contacting occurring under conditions of high shear sufficient to form a paste from said composition which plugs said porous formation.
A process for plugging an underground formation penetrated by a well which comprises transporting a shear thickening fluid to said formation under conditions of relatively low shear through a conduit extending into said well and then subjecting the shear thickening fluid to conditions of relatively high shear at that point of the formation desired to be plugged to form a paste which plugs said formation, wherein said shear thickening fluid comprises a water-in-oil emulsion having particles of granular, hydratable, water-expandable clay dispersed in the continuous oily phase thereof, said oily phase comprising a hydrocarbon oil and having a polyamine derivative surfactant dissolved therein and wherein said dispersed aqueous phase of said emulsion comprises an aqueous solution of both a polycarboxylic acid and a polyacrylamide and has a pH of less than 7 and wherein each droplet of dispersed aqueous phase is encapsulated by a film at the interface of the aqueous and oily phases.
A process for plugging a portion of a well bore which comprises pumping into said well, under conditions of low shear of less than about 100 sec..sup.-1 to the vicinity of said well bore desired to be plugged, a shear-thickening composition which comprises a water-in-oil emulsion having granular particles of hydratable, water-expandable clay dispersed in the continuous oily phase thereof, said oily phase comprising a hydrocarbon liquid having dissolved therein a polyamine derivative surfactant and said dispersed aqueous phase comprising an aqueous solution, having a pH below 7, of a polycarboxylic acid and a polyacrylamide, and subjecting said shear-thickening composition to relatively high shear conditions of at least about 2,000 sec..sup.-1 at the desired location of said well bore to mix the clay and aqueous phase of said shear-thickening fluid composition to form a paste which plugs said portion of said well bore and wherein each droplet of dispersed aqueous phase is encapsulated by a film at the interface of the aqueous and oily phases.
A process for plugging a portion of a well bore using a shear-thickening composition and an emulsion spacer wherein a conduit, which contains a fluid, extends down into the well bore from the surface thereof at least to the portion of said well bore desired to be plugged and wherein said shear-thickening composition comprises a water-in-oil emulsion having particles of hydratable, water-expandable clay dispersed in the continuous oily phase thereof, said oily phase comprising a hydrocarbon liquid having a surfactant dissolved therein which comprises a polyamine attached to an oil solubilizing hydrocarbon with or without an intervening bridging group and wherein said dispersed aqueous phase of said emulsion comprises an acid aqueous solution, having a pH below 7, of both a polycarboxylic acid and polyacrylamide, and wherein said spacer comprises a water-in-oil emulsion having a composition similar to the water-in-oil emulsion of said shear-thickening composition and wherein each droplet of dispersed aqueous phase of said shear-thickening composition is encapsulated in a film which forms as a result of the interaction of said polycarboxylic acid, surfactant and polyacrylamide, said process comprising the steps of:
A process for plugging a porous earth formation which comprises contacting said formation with a shear-thickening composition which comprises a water-in-oil emulsion having particles of hydratable, water-expandable clay dispersed in the continuous oily phase thereof said oily phase having a polyamine derivative surfactant dissolved therein and said dispersed aqueous phase of said emulsion comprising an aqueous solution of a polyacrylic acid and a polyacrylamide, said contacting occurring under conditions of high shear sufficient to form a paste from said composition which plugs said porous formation.
A process for plugging a portion of a well bore using a shear-thickening composition and an emulsion spacer wherein a conduit, which contains a fluid, extends down into the well bore from the surface thereof at least to the portion of said well bore desired to be plugged and wherein said shear-thickening composition comprises a water-in-oil emulsion having particles of hydratable, water-expandable clay dispersed in the continuous oily phase thereof, said oily phase comprising a hydrocarbon liquid having a polyamine derivative surfactant dissolved therein and wherein said dispersed aqueous phase of said emulsion comprises an aqueous solution, having a pH of no greater than about 7, of both a polyacrylic acid and a polyacrylamide, and wherein said spacer comprises a water-in-oil emulsion having a composition similar to the water-in-oil emulsion of said shear-thickening composition, said process comprising the steps of:
Dependencies are inferred from the claim text.