Prevention of Central Terminal Upsets Related to Stimulation and Consolidated Treatments

Much of the oil production from offshore Louisiana is sent by pipeline directly to an onshore terminal where the first oil and water separation is accomplished. The demulsification operation, which is capable of routinely producing pipeline oil, can be upset by returns from stimulation or sand control treatments on offshore wells, and separation at the terminal made extremely difficult. This study presents methods of identifying the treatments that cause the terminal upsets and provides a description of laboratory tests capable of indicating effective surface-active materials to incorporate in stimulation treatments to eliminate the terminal upset problem. Terminal upsets related to acidizing are thought to be caused by fine particles loosened from the formation by the acid. These fine particles cause stable emulsions in the presence of spent mud acid and effluent from certain sand consolidation treatments. Prevention of upsets requires altering the wettability of the particles by chemicals that are strong water wetters.