春风油田浅层超稠油HDNS技术研究

Research of HDNS technology for shallow super heavy oil reservoir in Chunfeng Oilfield

针对准噶尔盆地西缘春风油田浅层超稠油油层薄、地层热损失严重的难题,提出了水平井、降黏剂、氮气、蒸汽强化热采方式(HDNS)。氮气降低岩石导热系数,降低薄层稠油油藏沿上部盖层的热量损失。地层内氮气向上超覆,起到地层保温作用。降黏剂有效降低原油黏度,大幅降低了地下原油屈服值和原油能够流动的临界温度,延长了生产周期,增加了周期产油量。配套了注采一体化管柱和水平井大斜度泵工艺。春风油田应用HDNS技术已经建成产能61.7×104t/a,采油速度大于3%。

There are thinner layers and serious thermal loss in shallow super heavy oil reservoir in Chunfeng Oilfield on the west of Junggar Basin. Aiming at these difficult problems, this paper puts forward a HDNS thermal recovery technology which includes drilling horizontal wells, adding viscosity reducer, and injecting nitrogen gas and steam. Nitrogen gas can re- duce the thermal conductivity factor of rock and the heat loss of thin heavy oil reservoir along the top caprock. Upward o- verlapped N2 gas has heat preservation function for the formation. The viscosity reducer can effectively reduce viscosity of crude oil and significantly decrease the yield value of underground crude oil and the critical temperature of crude oil flow. As a result, production period is extended and periodic oil production is increased. The injection - production integration string and the high angle deviated pump technology for horizontal well were adopted. Using the HDNS technology, it is to form productivity of 61.7 ×10^4t/a with a oil production rate of more than 3.0% in Chunfeng Oilfield.