Ten-Year Pilot Test of Steam and Flue Gas Stimulation for Offshore Heavy Oilfield

Abstract

Abstract There is large amount of heavy oil resources whose oil viscosity over 350 mPa·s in Bohai Oilfield and their producing degree and production performance are relative low for lacking of effective exploitation technology. For seeking effective production technology for heavy oil exploitation, the steam and flue gas co-injection technology is proposed and studied. Considering the limited platform space, miniaturized steam and flue gas generator is designed and applied for field test. Besides, integrated matching technologies such as sea water desalinization, heat insulation, anticorrosion are also studied and developed. The south part of NN Oilfield was selected to be the target oilfield and the first thermal pilot area in Bohai Oilfield in 2008. Until now, the pilot in NN Oilfield has lasted for 10 years, nearly 30 well times of stimulation has been conducted and part of these wells has entered the third stimulation cycle. Compared with natural energy production, peak oil production and periodic oil production of thermal production are both greatly improved. With the increase of the stimulation cycle, the gas channeling problem has bad influence on the production performance, and the production rate declines rapidly. Steam flooding might be an effective replaced technology after huff and puff for further enhancing oil recovery of offshore heavy oilfields.