Research and application of compound steam huff and puff technology for heavy oil in Xinjiang oilfield

Aiming at the poor recovery effect of steam huff and puff in well field Hong003 of Xinjiang Oilfield, high performance composite chemicals with nitrogen assisted steam huff and puff complex technology is introduced to improve EOR of this area. Laboratory studies have found that effect of nitrogen on the crude oil viscosity is very small, but it can increase the elastic energy of formation; besides, compound viscosity reducer transform the heavy oil into Newtonian fluid when temperature is high, making start pressure disappears. Numerical simulation results on compound huff and puff of steam + Nitrogen + viscosity reducer have proved that pressure field, temperature field and viscosity field are better than that of steam injection. As a result production cycle can be significantly prolonged. 12 wells tests were carried out with this technology on site and yield production was significant, which can provide experiences and lessons for the rational development of same type heavy oil reservoirs.