基于地震波形驱动层序格架建立及页岩岩相特征研究--以松辽盆地古龙页岩油5号试验区为例  

Seismic waveform based sequence framework and study on shale lithofacies characteristics:a case study of No.5 test zone of Gulong shale oil in Songliao Basin

作　　者：何文渊 裴明波[2] He Wenyuan;Pei Mingbo(China National Oil and Gas Exploration and Development Co.,Ltd.;Research Institute of Exploration&Development,PetroChina Daqing Oilfield Company)

机构地区：[1]中国石油国际勘探开发有限公司 [2]中国石油大庆油田公司勘探开发研究院

出　　处：《中国石油勘探》2024年第2期123-133,共11页China Petroleum Exploration

基　　金：中国石油天然气集团有限公司重大科技专项“陆相页岩油规模增储上产与勘探开发技术研究”(2023ZZ15)。

摘　　要：松辽盆地古龙凹陷页岩油具有良好的富集条件和勘探开发潜力,已开展规模开发试验。目前,青山口组内部的细分层序地层研究还不够深入,影响古龙页岩油地质综合研究、甜点预测及部署。以松辽盆地古龙页岩油5号试验区为例,以地震层序地层学理论为指导,针对页岩型页岩油横向沉积相对稳定的特点,采用各向异性扩散滤波、层序识别与选取等手段,地震处理、解释及地质结合,使得地震波形可指示地质层位,形成基于地震波形驱动的层序格架建立技术。该技术实现了地震波形向沉积地层地质含义的快速转化,在研究区青山口组识别出1个二级、1个三级及8个四级层序界面,划分为Q1—Q9共9个小层,分析了各小层的格架特征,为页岩油岩相和甜点精细预测奠定基础。基于细分层地层格架,通过分析TOC、沉积构造、矿物成分、页理密度4个评价参数,建立了古龙页岩油页岩型岩相划分标准,划分为10类亚相。以研究区Q1—Q4小层为例,页岩岩相划分为3类亚相,描述了其平面分布特征。基于以上研究,结合含油性、脆性及物性等6个页岩油甜点参数的预测成果,在5号试验区优化布井11口,单井平均日产油在10t以上,有效支撑了松辽盆地古龙页岩油的效益勘探开发。Gulong Sag in Songliao Basin has good conditions for shale oil enrichment and promising exploration and development potential,and large-scale development tests have been conducted.At present,there is a lack of deep research on the subdivided sequence stratigraphy of Qingshankou Formation,which affects the comprehensive geological study,sweet spot prediction,and exploration deployment of Gulong shale oil.Guided by the theory of seismic sequence stratigraphy and based on the characteristics of relatively stable lateral sedimentation of shale type shale oil,No.5 test zone of Gulong shale oil is studied as an example,and seismic processing,interpretation(i.e.,anisotropic diffusion filtering,sequence recognition and picking),and geology are integrated to identify geological horizons by seismic waveforms,forming a sequence framework construction technology by using seismic waveforms,which has achieved rapid transformation of seismic waveforms into geological sedimentary sequences.In the study area,a total of one secondary,one tertiary,and eight fourth-order sequence boundaries are identified in Qingshankou Formation,and nine thin layers(Q1-Q9)are subdivided.The framework characteristics of all thin layers have been analyzed,laying the foundation for shale lithofacies identification and fine prediction of sweet spots.By analyzing four shale evaluation parameters,including TOC,sedimentary structure,mineral composition,and lamina density,a classification standard for shale type lithofacies of Gulong shale has been established based on the subdivided stratigraphic framework,and 10 sub lithofacies have been identified.For Q1-Q4 thin layers,three types of sub lithofacies are subdivided,and their plane distribution characteristics are characterized.Based on the above research and the prediction results by using six shale oil sweet spot evaluation parameters such as oil content,brittleness,and physical properties,11 wells have optimally been deployed in No.5 test zone,and an average oil rate of more than 10 t/d has been achiev

关 键 词：古龙凹陷 青山口组 页岩油 地震波形 层序格架 古地貌分析 岩相特征 

分 类 号：P631.4[天文地球—地质矿产勘探]