Microemulsions to convert OBM filter cakes to WBM filter cakes having filtration control
AssigneeBaker Hughes Incorporated
InventorsThomas A. Jones, David E. Clark, Lirio Quintero
Life of this patent
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Abstract
Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.
Claims17
A method of removing a majority of oil-based mud (OBM) filter cake particles from a hydrocarbon reservoir wellbore comprising:
- drilling a wellbore in a hydrocarbon reservoir with an OBM;
- forming a filter cake of OBM particles over at least part of the wellbore;
- contacting the OBM filter cake particles with a fluid selected from the group consisting of a nanoemulsion, a miniemulsion, a microemulsion and a single phase microemulsion without circulating the well, where the fluid further comprises a water-soluble filtration control additive selected from the group consisting of solid particulates, polymers and mixtures thereof such that a majority of the oil in the filter cake particles is incorporated into the fluid.
A method of removing a majority of oil-based mud (OBM) filter cake particles from a hydrocarbon reservoir wellbore comprising:
- drilling a wellbore in a hydrocarbon reservoir with an OBM;
- forming a filter cake of OBM particles over at least part of the wellbore;
- pumping into the wellbore a single phase microemulsion (SPME) gravel pack carrier brine having:
- sized gravel, and
- a water-soluble filtration control additive selected from the group consisting of solid particulates, polymers and mixtures thereof;
- placing a gravel pack into the wellbore;
- incorporating at least a majority of the OBM into the SPME by solubilization without circulating the well;
- changing the wettability of the filter cake particles from oil-wet to water-wet
- allowing the SPME to contact the filter cake for a time as a soak solution;
- and
- removing a majority of the filter cake particles.
Dependencies are inferred from the claim text.