复杂小断块油田中高含水期开发调整实践

由于小断块油田的复杂性,开发过程中需要不断调整完善,只有这样才能保证持续稳产。杨家坝油田为一强非均质复杂小断块油田,断层发育,构造复杂,目前已进入中高含水期,并表现出多种矛盾：注采井数比低,注水井吸水不均匀,油井多向受效率较低,高渗带水淹严重,且受断层影响使得局部井网不完善,稳产难度加大,迫切需要论证合理的开发调整方法．为油田后期的剩余油挖潜提供依据。针对开发中存在的问题,在详细研究最佳射开层数、射开厚度及油田最大产液量等参数的基础上,论证了合理划分开发层系、加强油层改造及提高油井排液量等措施可有效改善油田开发效果,并提出了卡堵改层、周期注水、水平井及侧钻井等技术在改善油藏开发效果方面的作用。研究结果表明,复杂小断块油田的开发调整多种方法和措施需要进行综合实施．且不同阶段针对的侧重点不同．卡堵改层、周期注水、水平井及侧钻井等技术在中高含水期可有效提高剩余油动用程度,保持油田稳产。

Practice of development adjusting at medium-high water cut stage for complex small fault-block oilfield

Since the complexity of small fault-block oilfield, adjustment and perfection are continuously needed in the process of development. Continuous stable production can be ensured only like this. Yangjiaba Oilfield is a complex small fault-block oilfield with severe nonhomogeneity, developed faults and complicated structures. The oilfield has gone into the medium-high water cut stage and many contradictions have emerged： low injection to producing well ratio, uneven water absorbing capacity of injection well, low multi-directional response rate of oil well, severe water out behavior of high permeability zone and regional imperfect well patterns because of the existence of faults, which makes the difficulty of continuous stable production increasing. The demonstration of appropriate development adjusting is urgently requested so as to provide a reference for remaining oil exploitation at the later period. For the existed problems in the process of development, based on the parameter demonstration of optimal numbers of perforated layer, optimal perforated thickness and maximal liquid producing capacity, this paper indicates the measures of dividing the layer series of development, reservoir stimulation and improving the fluid delivery of oil well, which can improve the development efficiency effectively. At the same time, some technologies that can play a great role in the improvement of development efficiency are also proposed, such as water shut-off and profile control, cyclic waterflooding, horizontal well and sidetracked well. The study results indicate that the development adjustment of complex small fault-block oilfield needs the comprehensive implementation of various methods and measures. Further more, the focuses of different periods are also different. At the medium-high water cut stage, water shut-off and profile control, cyclic waterflooding, horizontal well and sidetracking well techniques can effectively improve the producing degree of remaining oil and can preserve the stable production. All of these can provide a reference for the development adjustment at medium-high water cut stage of complex small fault-block oilfield.