低渗透油田特高含水期开发技术对策——以渤南油田义11井区为例

渤南油田义11井区平面、层间和层内非均质性严重，进入特高含水期后，注采矛盾突出，自然递减率达到14.8%，产量快速下降。为减缓递减，改善开发效果，开展了开发技术对策研究。针对主力油层主体部位动用程度高，水淹严重的状况，通过不稳定注水和优化油井采液强度，实现控水稳油；针对局部注采不完善，储量水驱动用程度低的状况，通过完善和恢复注采井网，提高储量水驱动用程度；对合采合注井，通过分层注水和封堵高含水层，减缓层间矛盾；对采出程度低，含水率低的砂体边部和非主力油层，通过储层改造、分层注水、单层开采等措施，提高储量动用程度。区块开发效果明显改善，年递减率下降至4.1%，基本保持稳定，采收率进一步提高，由30.7%提高到32.0%。

echnical treatment in extra-high water cut stage for low permeable reservoircase study of Yi11 area, Bonan oilfield

Due to the serious heterogeneity in plane, interlayer and layer, it is full of imbalances in injection-production pattern, and the production decline reaches 14.8% in Yi11 area of Bonan oilfield, so the technical treatment is needed to ameliorate the decline of the development. The non-stable injection and optimized liquid yielding are adopted to control the water and stabilize oil production in response to the high water cut and serious flooding in the major oil-production layers. Moreover, the water drive producing reserves are produced by improving and completion of well pattern in response to incomplete injection-production pattern. The interlayer problems are resolved by means of layer-oriented injection and plugging of high water cut layer. For the sand body edge and secondary oil-bearing layers, the reservoir reformation, intensive injection, individual layer production are adopted to enhance the reserve utilization. The development effect is remarkably improved. The production decline rate decrease to 4.1% and the recovery factor is further increased from 30.7% to 32%.