论文详情
塔里木盆地巴麦地区的地震资料受复杂地震地质条件的影响,层间多次波广泛发育,识别和压制难度大,导致奥陶系碳酸盐岩断控缝洞型储层成像不准确,制约了该地区油气勘探部署。通过模型正演及邻区VSP波组特征标定分析,明确了层间多次波产生的必要条件、发育特征及对有效反射信号的影响,并有效识别出二叠系火成岩巴楚组标准灰岩、二叠系不整合面小海子组灰岩等多套产生层间多次波的“源镜”组合,形成了“两步法”层间多次波叠后压制技术:首先利用多次波分布规律,采用匹配追踪法压制层间多次波;然后基于剖面频率特征,利用优势频率信息提取技术,压制高频层间多次波并增强资料信噪比。研究区实际资料处理结果表明,该方法能够有效压制奥陶系内幕层间多次波,提升目的层断控碳酸盐岩缝洞型储层成像质量。
In the Bamai area of the Tarim Basin,internal multiples are widely developed due to the complex seismic geological conditions.These multiples are difficult to identify and suppress,which leads to inaccurate imaging of fault-controlled carbonate fractured vuggy reservoirs and restricts the deployment of oil and gas exploration.Based on the analysis of the forward modeling method and the calibration of the wave characteristics of drilling VSP data,this study defines the prerequisite for the formation of internal multiples.The development characteristics and their influence on the effective reflection signal were determined.Multiple sets of “source mirror” combinations were effectively identified,such as the Permian igneous rock-Bachu Formation standard limestone and Permian unconformity surface-Xiaohaizi limestone formation.A “two-step” poststack internal multiple suppression method was formed.First,based on the understanding of the multiple distribution law,the matching pursuit method was used to suppress internal multiples; second,based on the frequency characteristics,the dominant frequency band was extracted to suppress the high-frequency internal multiples and enhance the SNR of the data.The field data results show that this method can effectively suppress Ordovician internal multiples and improve the imaging quality of fault-controlled carbonate fractured vuggy reservoirs.