| abstract |
This invention provides an additive composition for use for example in drilling, completion and workover fluids that minimizes production formation damage by increasing well clean up efficiency and aids in recovering oil held in place by dynamic capillary forces between oil, water and injected fluids, driving down the water saturation of the formation resulting in an increase in permeability to oil and resulting production. These additives, found to be especially useful in 38% calcium chloride workover and completion fluids, are also effective in 25 and 10% sodium chloride workover and completion fluids, as well as other brines, including bromides. The additives of this invention, when added to fluid workover and completion fluids, in addition to reducing interfacial tension in production formations to minimize water blocks resulting from use of workover and completion fluids, and compatability with brines, also promote water wetting, demulsification and are thermally stable over a useful range. These novel additives contain three essential ingredients, a diester monosulfosuccinate, a polypropoxylated quaternary ammonium chloride, and a sodium alkylaryl polyether sulfate. |