川东北元坝地区长兴组生物礁的识别

Identification of reef reservoir of Changxing formation in Yuanba area of Northeastern Sichuan Basin

元坝地区长兴组具有发育礁滩储层的沉积背景,地震剖面上显示有礁滩反射异常体,对钻遇长兴组礁滩储层的井进行含气性测试,获得了工业天然气流。长兴组埋藏深,地震资料的分辨率低,生物礁储层预测困难。综合多种方法对元坝地区的生物礁进行了识别。首先基于正演模拟结果和连井地震剖面,归纳总结了生物礁的地震响应模式;然后基于三维地震资料,识别了长兴期末期沉积地层的沉积相;最后基于三维地震数据体,应用波形分类技术、分频处理技术、相干体识别技术和古地貌恢复技术对长兴组生物礁的平面分布特征进行了刻画。较好地描述了长兴组生物礁的形态和展布特征。

Reef-flat reservoirs are developed in Changxing formation of Yuanba area.With this sedimentary background,some reef-flat seismic abnormal bodies have been discovered here.Commercial gas flow was obtained by gas testing in the wells encountered the reef reservoirs.The Changxing grouop is deep buried and its seismic data is with low resolution,which leads to the difficulty in reef reservoir prediction.Aiming at the problem,some methods were integrated to identify the reef in Yuanba area.Firstly,based on forward modeling results and well-tie seismic sections,the seismic response patterns of reef were concluded.Then,based on 3-D seismic data, the sedimentary facies of Changxing telophase was identified.Finally, based on 3-D seismic data volume,waveform classification recovery technique,frequency-division processing,coherent cube recognition technique and paleo-geomorphology technique were used to describe the plane distribution of reef in Changxing formation.The method has good effect,and well describes the shape and distribution characteristics of reef in Changxing formation.