阿北安山岩油藏裂缝注水研究

RESEARCH ON WATER FLOOD OF THE FRACTURED A-BEI ANDESITE RESERVOIR

阿北安山岩油藏储层由三期火山喷发形成 ,具有典型双重介质渗流特征 ,注水开发后由于注入水沿裂缝窜流 ,造成油藏含水上升速度快 ,产量递减大。为了改善油藏开发效果 ,根据裂缝发育规律设计了裂缝注水岩块采油等 5种类型 13个方案 ,应用FIFS油藏数值模拟软件优化沿裂缝注水岩块采油方案 ,提出了利用原井网实施沿裂缝注水岩块采油 ,以及周期注水 ,整体化学调剖等综合“调水增油”措施方案。经过 6年的现场实施达到了方案设计指标 ,综合含水下降 4% ,累计增产油量 4.2× 10 4 t,提高采收率 2 .5 % ,取得了十分明显的效果。

The A-Bei andesite reservoir was formed as a result of three phases of volcanic extrusions, and it exhibits characteristics of a typical double-porosity system. During waterflood recovery, the water cut increased very fast and production declined quickly as a consequence of injected water channeling along fractures. To cope with this problem, detailed studies on the regularity of fracture occurrences were carried out and, based on the information gained, five kinds of waterflood plans were designed and altogether 13 different programs were performed. The FIFS reservoir numerical simulation software is used to optimize the programs. The proposed measures include 'injection along fractures and production from matrix blocks' and 'periodical injection and overall adjustment of injection profile with chemical agents'. After six years of performance, the water cut is decreased by 4%, the cumulative increase of oil production is 4.2×10 4t, and the recovery is increased by 2.5%. The knowledge and experience gained from this work may provide useful reference for the injection program of similar reservoirs.