Key technology of gathering and transportation of ultra-thick high-sulfur crude oil in Tahe Oilfield

As an Ordovician carbonate karst vuggy extra-heavy unsaturated bottom-water reservoir, the super heavy oils in the Tahe Oilfield are featured by ultra-deep, ultra-thick, high viscosity, high-density, high content of H₂S, high salinity and other characteristics. Acid fracturing is in large scale, and development and ground gathering are difficult. The SINOPEC Northwest Oilfield Company, through scientific research, has solved the problems in the gathering and transportation of ultra-thick crude oil. The gathering and transportation technique by mixing light oil to decrease viscosity is innovated. The desulfurization technique by gas extraction is applied for the first time on heavy oil rich in H₂S, breaking heavy oil dehydration process to achieve the closed gathering of ultra-heavy oil.