综合沉积正演与多点地质统计模拟碳酸盐岩台地——以巴西Jupiter油田为例

为有效提高碳酸盐岩沉积相(岩相)模拟的精度,以巴西Jupiter油田为例,在岩心、测井及地震资料综合分析的基础上,通过多条件约束建立该地区碳酸盐岩台地沉积正演模型,以此作为多点地质统计模拟的三维训练图像,并利用成熟的Snesim算法对实际油田数据进行模拟。研究结果表明:沉积正演模拟初始控制条件对碳酸盐岩台地沉积分布影响较大,主要包括水深、风向、波浪能量、碳酸盐岩产率等,其中水深(主要影响温度和光照)对碳酸盐岩产率影响最大;波浪能量大小控制不同类型碳酸盐岩分布特征,高能环境沉积物主要为生物礁及颗粒灰岩,低能环境沉积物主要为泥晶灰岩;碳酸盐岩沉积正演模型体现了高能生物礁与低能泥晶灰岩的渐变接触关系,符合碳酸盐岩生长规律,将其转化为三维训练图像,多点模拟结果既满足所有钻井认识又体现了训练图像反映的相结构关系。本研究总结了碳酸盐岩台地沉积正演模拟的分析方法,提出三维训练图像获取较新的思路,综合了沉积正演模拟与多点统计模拟的优势,并在实际油田应用中取得一定效果,对类似孔隙性碳酸盐岩油藏地质建模具有借鉴意义。

Integrated sedimentary forward modeling and multipoint geostatistics in carbonate platform simulation:a case study of Jupiter oilfield in Brazil

To effectively improve the accuracy of carbonate sedimentary facies (lithofacies)simulation, based on integrated analysis of core data, logging data and seismic data of Jupiter oilfield in Brazil, multi-condition constraint is used to create the sedimentary forward model of regional carbonate platform as the 3D training image of multipoint geological statistical simulation. Meanwhile, the mature Snesim algorithm is applied to simulate actual oilfield data. Research results demonstrate that the sedimentary forward modeling of initial control conditions make great impacts on the sedimentary distribution of carbonate platform, mainly including water depth, wind direction, wave energy and carbonate production. Among them, water depth (mainly affecting temperature and light)has the most influence on carbonate production. The distribution characteristics of different carbonate types were controlled by wave energy magnitude. High-energy environmental sediments mainly include reefs and grain stones, while low-energy environmental sediments are dominated by micrite. The sedimentary forward model of carbonate also reveals the changing contact relationship between high-energy reefs and low-energy micrite, consistent with carbonate growth rules. Then, it is converted to 3D training image, and multipoint simulation results are not only coincident with drilling understanding but also reflect the facies structure relation reflected by training image. Through summarizing the sedimentary forward simulation analysis method of carbonate platform, a new approach of acquiring 3D training image is proposed in this study; as integrating the advantages of sedimentary forward modeling and multipoint statistical simulation, it has a good application in oilfield and provides a reference for the geological modeling of porous carbonate reservoir.