应用压降叠加原理指导高渗透油藏注采调配

Applying dropout superposition to injection and production allocation for high permeability reservoir

梁家楼油田的纯47块、纯56块,开发层系沙三中,储层为顶平底凸的单一大厚层,平均油层厚度18.6m,平均空气渗透率2.084μm2,为特高渗透油藏。经过30多年的注水开发,已进入特高含水开发阶段,稳产的主要手段之一是通过注足水、注好水来实现稳液稳油和控水稳油。为解决该类油藏注水见效敏感、注采调配理论依据不足的问题,以油藏渗流力学为理论基础,经过深入研究、反复论证,选择压降叠加原理作为注采调配的理论依据。通过对油藏地层参数重新取值及论证,得到了适用于该油藏的压降叠加公式,进一步推导出注采调配见效周期的计算公式。运用所得公式指导注采调配,取得了较好的效果,达到了降低自然递减率、改善油藏水驱状况的目的,增加可采储量20.8×104t。

Liangjialou Oilfield X47 and X56 blocks, the developing Sha3 layer, is a thick flat top- bottom convex reservoir, with average reservoir thickness of 18.6 meters, and average air permeability of 2. 084lμm^2. It is an ultra-high permeability reservoir. After 30 years＇ waterflooding, it has entered a very high water cut phase. The production has been stable by water injection effectively. In recent years, to solve many problems, such as sensitive reservoir to waterflood,lack of theoretical basis for injection-production adjustment, reservoir seepage mechanics as theoretical foundation, after study and demonstration, the pressure drop superposition is selected as a theoretical basis for injection and production adjust- ment. Through taking formation parameters again and repeated appraisals, the reservoir pressure drop superposition formula is gained to derive injection-production cycle formula for calculating the results. Applying the formula to guide the injection-production deployment, good results have been achieved to reduce the natural decline rates, to improve reservoir water flooding,and to increase the recoverable reserve of 20.8 × 10^4t.