一个可能的生物礁预测

A possible organic reef

中国石化新星公司西南分公司第二物探大队,四川德阳618000

The Second Geophysical Prospecting Party of SINOPEC Star Petroleum Exploration & Production, Deyang 618000, China

礁体预测是长兴组储层预测的关键, 然而“想打的打不到, 不想打的又碰到”是长兴组生物礁预测现实状况的描述。相关的研究将生物礁的反射特征归结为直接标志和间接标志两大类, 但现有资料表明, 具有这样典型反射特征的生物礁是少部分, 大多数生物礁反射特征并不明显。在石柱复向斜建南构造带上, 发现了长兴组顶一个很明显的异常反射, 通过礁体的沉积特征、地震相特征及AVO响应特征对该异常反射进行全面分析, 认为很可能是礁的异常反射, 但有待钻井最终验证。

The key to prediction of reservoirs of Changxing Formation is the prediction of reef. However, it is common that the predicted reefs are always turned out to be wrong. Previous studies revealed that the reflection characters of organic reefs might be classified into direct and indirect indications. In practice, however, it is rare for reefs to have both such indications. An obviously abnormal reflection has been found in the Jiannan structural unit, Shizhu synclinorium. From the analyses of depositional characters, seismic facies, and AVO responses, the author concludes that it might be the reflection of a reef. The conclusion needs to be verified by drilling.