Patent ID: 11926789
Assignee: BAKER HUGHES OILFIELD OPERATIONS LLC
Field: Basic materials chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 0:
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.