ENCAPSULATED GAS FOR DRILLING AND COMPLETION FLUIDS

摘要

Gas-core microstructures, such as microbubbles, may be used in drilling and completion operations in the exploration and production of hydrocarbon fluids (e.g. oil and gas) from subterranean formations. The gas-core microstructures are dispersed in a base fluid such as water, oil or emulsions of water and oil, in accordance with the specific performance needs. Applications for fluids containing these gas-core microstructures include, but are not necessarily limited to, use as a spacers to control trapped annular pressure, use as low density drilling fluids, use as dual gradient drilling fluids and the delivery of chemicals downhole.

主权项

1. A method for introducing encapsulated gas into a subterranean structure selected from the group consisting of a wellbore and a subterranean formation, the method comprising:
pumping through a wellbore a wellbore operations fluid comprising:
a base fluid selected from the group consisting of water, oil and an emulsion of water and oil;a plurality of gas-core microstructures each comprising:
a gas-filled core;a shell selected from the group consisting of:
surfactant-based single-wall shells;surfactant-based multiple-wall shells; andrigid polymer-based shells which are not an elastomer;where the wellbore operations fluid is selected from the group consisting of drilling fluids, drill-in fluids and completion fluids; and performing at least one additional step selected from the group consisting of:
controlling trapped annular pressure;controlling gas migration in cement;delivering the gas in the gas-filled core to a predetermined location;releasing the gas in the gas-filled core to a predetermined location and reacting the gas with another reactant at a predetermined location;drilling a borehole with a low density drilling fluid having a density from about 6.0 to about 8.3 ppg (about 0.7 to about 1 kg/liter);drilling a borehole with the wellbore operations fluid, where the wellbore operations fluid is at least a dual gradient drilling fluid; andcombinations thereof.