聚合物驱后井网调整与非均相复合驱先导试验方案及矿场应用——以孤岛油田中一区Ng3单元为例

为了进一步提高聚合物驱后油藏原油采收率,提出了井网调整与非均相复合驱相结合的提高采收率方法,并在孤岛油田中一区Ng3单元开展了先导试验。根据试验区油藏特点,将原井网调整为变流线强波及的135 m×150m行列式井网;研制了由粘弹性颗粒驱油剂B-PPG、聚合物和表面活性剂配制而成的非均相复合驱油体系,2010年7月,试验区新钻油井投产,新水井投注,于2010年10月开始注入前置调剖段塞。矿场应用效果显著:注入井平均注入压力上升了2.6 MPa,启动压力平均上升了2.7 MPa,霍尔阻力系数达2.2;流线分布更均匀,驱替更均衡;试验区总产油量由4.5 t/d上升到81.2 t/d,油井综合含水率下降了18.5%,截至2013年2月,已累积增产原油4.3×104t,提高采收率3.5%。

Application of pilot test for well pattern adjusting heterogeneous combination flooding after polymer flooding-case of Zhongyiqu Ng3 block, Gudao oilfield

Well-pattern improvement and combined heterogeneous-phase flooding are initiated for the reservoir after polymer flooding and applied in Zhongyiqu Ng3 block, Gudao oil plant of Shengli oilfield. According to the reservoir conditions, the specific EOR project is designed, including 135 m×150 m well-pattern which can change the flooding direction and enlarge sweeping capability, and then fabricated the heterogeneous combination system combined with B-PPG, surfactant and polymer. The EOR project is applied, as the first candidate, on the Ng3 block and achieved great success. The injecting pressure and starting pressure rose 2.6 MPa and 2.7 MPa respectively, and resistant factor attained up to 2.2, showing that the flooding sweeping is more homogenous. The water cut of field pilot decreased by 14.5%, and the oil rate rose to 81.2 t/d from 4.5 t/d. The project has increased oil output by 43 000 t and recovery factor by 3.5%.