基于地震多属性融合与地质统计学反演的薄层砂岩预测

Thin Sandstone Prediction Based on Multi-Seismic Attribute Information Fusion and Geostatistical Inversion

阐述了塔里木盆地塔北隆起带南缘英买力YM1-2地区舒善河组薄层砂岩勘探的难点与研究意义,提出了针对YM1-2地区舒善河组薄层砂岩预测的技术方法。平面上利用地震资料横向密集性采用地震多属性融合分析方法,通过薄层砂岩的属性优选与提取,计算钻井厚度与属性的相关关系,提取与薄层砂岩厚度相关度大的属性,多属性统计融合预测了薄层砂岩平面分布;垂向上采用地质统计学反演方法,在测井曲线标准化处理、反演低频模型建立的基础下,对钻井进行岩性估算、概率密度函数和变差函数分析,利用马尔科夫链蒙特卡洛模拟反演,预测了YM1-2地区舒善河组薄层砂岩2套砂体的有利圈闭发育区。研究发现,薄层砂岩主要分布于YM1~YM2鼻状构造带上,整体呈北东-南西向条带状展布,平面上呈现多个砂体由南东-北西向叠置前积。舒善河组薄层砂岩的预测厚度与钻遇厚度高度一致,符合率高达90%以上。

This paper analyses the significance and problems of thin sandstone exploration in Shushanhe Formation at the north uplift Yingmaili area in Tarim Basin, and presents relevant techniques and methods about thin sandstone prediction. The plane distribution ofthin reservoir was achieved by using the following methods： multiple seismic attribute information fusion, extraction and optimization of seismic attrib- utes, correlation coefficient calculation between seismic attributes and drilling sand body thickness, extrac- tion of highly correlated seismic attributes with the thickness of sand body, and statistical regression meth- od. The vertical distribution of two thin sand bodies was reached by using the following methods： geosta- tistical inversion algorithm prediction, logging curves standardization, inversion of low frequency model building, lithology curve calculation, probability density function analysis, variogram analysis, and Markoff Montecalo simulation and inversion. The results showed that the thin sand bodies of Shushanhe Formation are mainly distributed in the YM1--YM2 nosing structure with NE-SW banded distribution pattern. The plane distribution of thin sand bodies of Shushanhe Formation presents NW-SE multiple sand bodies stacked progradation pattern. The predicted thickness are basic consistent with the drilled thickness, the coincidence rate is above 90%.