PREVENTING FORMATION DAMAGE CAUSED BY HIGH-DENSITY COMPLETION-FLUID/CRUDE-OIL EMULSIONS

摘要

Recent laboratory work and field case histories identified emulsions that reduced well productivity after gravel packing certain oil-producing wells in the Gulf of Mexico (GOM). Laboratory investigation identified the emulsifying agent as the calcium chloride (CaCl_2)/calcium bromide (CaBr_2) completion fluid used in the gravel-pack pumping procedure. Remedial procedures were performed to remove the damage. Succeeding oil wells were evaluated for completion-fluid/crude-oil compatibility before performing a gravel pack. A nonemulsifier surfactant from the pumping company's acid-additive product line was effective in preventing emulsions when added at high concentrations in combination with a mutual solvent.