河流砂岩地震储层预测中的几个问题

河流砂岩是陆相盆地常见储层类型及油气储集有利场所。由于河流改道迁移频繁,河流相沉积常为砂、泥岩交互且岩性横向变化快,造成地震反射呈断续特征,利用常规地震资料进行砂、泥岩分辨和预测难度很大。笔者在分析河流砂岩地质特征和地球物理响应的基础上,研究和讨论了砂岩的精确标定、等时地层格架下的精细解释和地震属性提取,优选地震振幅类属性和分频处理预测薄层砂岩的平面展布,构建合理的地质模型,优选参数进行拟声波反演预测砂岩垂向分布及厚度变化等储层预测中的技术问题。通过实际应用和资料验证,采用技术方法合理,并取得了高精度的预测结果。

SEVERAL PROBLEMS CONCERNING RESERVOIR PREDICTION OF FLUVIAL SANDSTONE

Fluvial sandstone commonly constitutes a reservoir in the continental depression. Frequent river diversion, growth of interbedded sandstone and mudstone and fast lateral variation have resulted in interrupted seismic reflection. The reservoir prediction is therefore very difficult. In this paper, precise interpretation of stratigraphic position and isochronous parallelism of strata was made according to actual data. Optimized seismic attributes were extracted, frequency division of thin layers was studied, and river channel distribution in plan was predicted by using the result of frequency division. Simulated sonic inversion using optimized parameters yielded the high precision prediction result. Drilling verification shows that the technology used is very effective.