薄层生物碎屑灰岩的地震属性检测

Detection of thin-layer bioclastic limestone based on seismic attributes

（1.中国石油大学资信学院，北京102249；2.中国石油大学CNPC物探重点实验室，北京102249；3.中国石油化工股份有限公司石油勘探开发研究院，北京100083）

College of Resources and Information, China University of Petroleum, Beijing 102249, China

地震反射的薄层干涉限制了利用地震反射结构识别薄互层地层的能力，而地震属性隐含了地下介质三维非均质性分布信息，为此，探讨了通过地震属性的统计特性检测薄储层的能力。在黄骅坳陷某区，提取了古近系沙河街组一段下段（沙一下段）20ms时窗内的平均振幅和主频属性，统计分析了这2个属性异常与钻井岩性的对应关系；对多口钻井沙一下段各类岩石的声波时差进行了分析，总结出地震属性异常分布与井点岩性及其厚度的关系，得到在40～50Hz的地震主频下高速的生物碎屑灰岩和部分砂岩对属性特征起决定性作用的认识。对薄层生物碎屑灰岩地震属性检测的研究表明，岩石物理参数分析是确定地震属性解决地质问题能力的关键因素。

Thin-layer interference of seismic reflection constrains the ability of recognizing thin interbed formations from seismic reflection structure. However, seismic attributes involve the 3-D distribution of anisotropy of thin layers. So, the ability of detecting thin reservoirs through seismic attributes was probed. In some area of Huanghua depression, the average amplitude and domain-frequency attributes of target strata (the lower Es1 member of Shahejie group) in 20 ms time window were extracted, and their relationship with drilling lithology was statistically analyzed. The acoustic moveout of many wells in the lower Es1 member was analyzed. The relationship of seismic attribute anomaly with lithology and thickness of well point was concluded. This indicates that high-speed bioclastic limestone and part of sandstone in the domain frequency of 40-50 Hz is the determinative factor of attribute characteristics. The seismic attribute detection of bioclastic limestone from thin layers shows that rock physical parameters analysis is the key factor for the ability of seismic attributes in solving geological problems.