“双控”地质建模技术的实践与认识——以渤海湾盆地SZ36-1油田为例

Practice and understanding of double controlled geological modeling technology:A case study on SZ36-1 Oilfield in the Bohai Bay Basin

目前渤海湾盆地多数油田已进入高含水期开发阶段,油藏模型、油水系统及面临的开发问题十分复杂,严重制约了油田可持续发展。为此,提出一套基于地震反演和沉积微相约束的建模方法,结合渤海湾盆地SZ36-1油田地质资料,以地震合成记录为桥梁,构建了基于相控"硬约束"和地震反演"软约束"的孔隙度模型。可信度分析认为该方法优势体现在:(1)基于双控的地质模型消除了硬约束的"痕迹",与岩相砂体发育趋势相吻合,且具有一定的井间预测功能,模型更符合地质认识;(2)模型具有较高精度的同时降低了地震约束建模的局限性。后验井平均符合率达92.51%,说明地震约束建模技术能够降低地质模型的不确定性,可信度较高。基于地震约束地质模型方法有助于进一步提高水驱采收率。

At present,most offshore oilfields,especially in the Bohai Bay Basin,have entered into development stage with high water cut.This paper proposes a constrained modeling technology based on seismic inversion and sedimentary microfacies.Taking the SZ36-1 Oilfield in the Bohai Bay Basin as an example,aporosity model is built by using synthetic seismic records as a bridge,sedimentary microfacies as a"hard constraint"and seismic inversion as a"soft constraint".The method has technical advantages as follows:(1)The geological model based on double constraints is consistent with actual geological understanding.The model hasn’t the"trace"of the hard constraint.It is not only conformed to the development of sandstone lithofacies,but also can predict inter-well development.(2)The model has higher accuracy and the average coincidence rate of posterior wells is up to92.51%.In addition,it can reduce the uncertainty and the limitations of a geological model.The model based on double constraints is helpful to provide strong technical support for improving waterflooding oil recovery.