CPC C09K 8/524 (2013.01) [C09K 8/035 (2013.01); C09K 8/536 (2013.01); C09K 2208/30 (2013.01)] | 4 Claims |
1. A solid weighting agent-free, brine-based viscosified pill formulation for displacement or removal of a drilling fluid, the formulation comprising:
about 80 vol. % to about 95 vol. % viscosified brine; and
about 5 vol. % to about 20 vol % of a surfactant-solvent blend comprising:
about 5 wt. % to about 40 wt. % of at least one non-ionic surfactant;
about 5 wt. % to about 20 wt. % of at least one polyglycerol ester;
about 20 wt. % to about 60 wt. % of at least one co-solvent;
about 20 wt. % to about 25 wt. % water; and
about 1 wt. % to about 15 wt. % of at least one hydrophobic solvent, wherein the at least one hydrophobic solvent is an olefinic ester; and
where the formulation contains no solid weighting agents, and does not form a microemulsion.
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