地震沉积学技术在文昌A油田储层预测中的应用

Application of Seismic Sedimentology Technology in Reservoir Prediction of Wenchang A Oilfield

文昌A油田主力油组ZJ1-2L储层以滨海临滨环境的沿岸砂坝和下临滨席状砂沉积为主,该区钻井分布少、典型地震相标志少,储层厚度自东向西逐渐减薄至小于地震资料分辨率,砂体边界的确定严重制约着油田的开发实施。面对常规储层预测技术手段受限的问题,利用地震沉积学的思想,首先用分频解释技术确定了等时沉积参考面,并通过Wheeler变换,在研究区层序地层等时格架的基础上制作了一系列地层切片,通过对地层切片的解释及域演观察识别出了砂体的演变规律,在此基础上,结合分频反演技术,精细刻画出了ZJ1-2L油组砂体平面分布范围。开发实施结果表明,该技术刻画的砂体范围与实钻结果有很好的吻合度。

The point bar of coastal offshore environment and the deposition under offshore sheet sand are developed in ZJ1-2L oil group reservoir of Wenchang A Oilfield. The development of this oilfield is seri- ously constrained by its few wells, few typical seismic facies indexes, the gradual westward thinning of the reservoir until the thickness is smaller than the seismic data resolution and the difficult determination of the sandbody boundary. As the conventional reservoir prediction techniques cannot solve such problems, the paper adopts seismic sedimentology techniques to characterize the sandbody border. The time deposit reference plane is determined by the frequency division interpretation technology. According to the Wheel- er transformation, a series of stratigraphic sections based on sequence stratigraphic isochronous trellis are established. The plane distributions of the sandbodies in different periods are presented by the interpreta- tion of strata slices and domain play observation. The combination of frequency division inversion tech- nique is applied based on above techniques and successfully achieves the fine description of reservoir distri- bution. The development and implementation results show the research results have a good coincidence in drilling data.