松辽盆地古龙页岩油富集层地球物理定量表征方法及其应用

Quantitative geophysical characterizing method and its application for Gulong shale oil enriched layers in Songliao Basin

松辽盆地古龙页岩为陆相淡水湖盆沉积,地质条件优越、资源量潜力大,与海相页岩油相比,具有自身的特殊性,相应的地球物理定量评价方法匮乏。在岩心、测井、地震、地质等多种资料综合分析的基础上,提出了古龙页岩油富集层井—震联合定量评价技术体系。以岩石物理分析为基础,确定古龙页岩油富集层岩石物理特征,优选w(TOC)、总孔隙度、脆性等富集层地质工程参数的敏感弹性参数,建立基于弹性模量和泊松比的新弹性参数脆性评价因子;通过叠前地质统计学反演获得高精度弹性参数反演数据体,并根据岩石物理分析结果进行古龙页岩储层w(TOC)、总孔隙度、脆性等富集层地质工程参数的地震定量预测;再利用叠后地震属性分析裂缝检测技术及叠前各向异性反演手段,实现高角度构造缝和水平页理缝地震定量表征;对w(TOC)、总孔隙度、脆性和裂缝等参数的预测结果进行综合分析及评价。结果表明:研究区地震预测结果与实钻结果吻合较好,w(TOC)、孔隙度、脆性等参数预测符合率较高,证实了地震预测方法及结果的可靠性。研究成果为松辽盆地古龙页岩油富集层的勘探开发提供有力的依据。

Gulong shale in Songliao Basin is continental freshwater lake deposit,with superior geological conditions and great resource potential.Unlike marine shale oil,it has particularity and needs corresponding quantitative geophysical evaluation methods.Based on comprehensive analysis of various data including core,logging,seismic and geology,this paper proposes well-seismic tie quantitative evaluation technology system for Gulong shale oil enrichment layers.Petrophysical characteristics of Gulong shale oil enrichment layer is determined on the basis of petrophysical analysis.Sensitive elastic parameters of enrichment layer geological and engineering parameters of w(TOC),total porosity,and brittleness are optimized,and new elastic parameter brittleness evaluation factor based on elastic modulus and Poisson’s ratio is established.High accuracy elastic parameter inversion data volume is obtained via pre-stack geostatistical inversion,and seismic quantitative prediction of geological and engineering parameters of w(TOC),total porosity and brittleness of Gulong shale reservoir is carried out according to petrophysical analysis.Then,quantitative seismic characterization of high angle structural fractures and horizontal lamellation fractures is performed by applying post-stack seismic attribute analysis fracture detection technique and pre-stack anisotropic inversion method.Finally,prediction results of w(TOC),total porosity,brittleness and fractures are comprehensively analyzed and evaluated.The results show good agreement between seismic prediction and drilling results,with high prediction coincidence rates of w(TOC),total porosity and brittleness,confirming the reliability of seismic prediction method and results which can provide evidence for exploration and development of Gulong shale oil enrichment layers in Songliao Basin.