砂泥岩层系中油源断裂输导油气优势路径演化及识别研究

The result of hydrocarbon exploration indicates that hydrocarbon distribution was mostly controlled by advantageous pathway of oil-source fault transporting hydrocarbon in petroliferous basin of sandstone-mudstone rock from lower source to upper reservoir. In order to study advantages pathway evolution and recognition of oil-source fault transporting hydrocarbon in sandstone-mudstone strata in different periods, this project aims to utilize field profile, wells and seismic data as basis, to make a research of inner structure and transportation pathway character of oil-source fault in static period. Through formation and evolution character of fault and physical modeling experiment, a research was made to study oil-source fault transporting hydrocarbon pathway in active period. Utilizing ancient activity rate and shale content in filling material of oil-source fault at known wells, combined with hydrocarbon distribution, to make separate determination of the minimum ancient activity rate required by accompanied fracture formation and the maximum shale content required by transporting hydrocarbon through filling material in oil-source fault, then combined with rock types which were favorable for fracture development and distribution of convex ridge of fault plane, to make separate recognition of favorable position of oil-source fault transporting hydrocarbon through layers in active period and static period. Based on hydrocarbon potential, character of oil or changing character of nitrogenous compounds in favorable positions, advantageous pathway of oil-source fault transporting hydrocarbon can be recognized comprehensively in active period and static period. Through this project, hydrocarbon distribution around oil-source fault can be predicted more accurately, and hydrocarbon exploration can be guided effectively.

油气钻探结果表明，含油气砂泥岩盆地下生上储式油气分布主要受到油源断裂输导油气优势路径的控制。为了研究砂泥岩层系中油源断裂输导油气优势路径演化及识别，本项目拟在充分利用野外露头、钻井和地震资料的基础上，研究静止期油源断裂内部结构及输导通道特征。通过断裂形成与演化特征和物理模拟实验，研究活动期油源断裂输导油气通道特征。利用已知井点处油源断裂古活动速率和填充物泥质含量，结合油气分布，分别确定油源断裂伴生裂缝形成所需的最小古活动速率和填充物输导油气所需的最大泥质含量，再分别与有利于裂缝发育岩石类型和凸面脊分布进行耦合，分别识别活动期和静止期油源断裂输导油气所经层位的有利部位。根据有利部位处油气势能相对大小和原油物性或含氮化合物含量变化特征，综合识别活动期与静止期油源断裂输导油气优势路径。通过本项目研究，可以更加准确地预测油源断裂附近油气分布，有效指导油气勘探。

油源断裂是含油气盆地下生上储式油气运移的主要输道通道，其优势路径识别对含油气盆地油源断裂附近油气勘探至关重要，目前对油源断裂输导油气优势路径的识别虽有了较大进展，但仍存在很多不足之处。本项目通过野外和钻井资料在油源断裂内部结构研究的基础上，将油源断裂输导油气通道分为活动期伴生裂缝和停止活动后可渗漏油气断裂填充物2种类型。通过油源断裂古活动速率和被其断开地层脆塑性，综合识别活动期油源断裂输导油气优势路径——伴生裂缝发育部位。通过断裂填充物泥质含量和填充物输导油气所需的最大泥质含量，综合识别停止活动后油源断裂输导油气优势路径——可渗漏油气断裂填充物发育部位。由活动期和停止活动后油源断裂输导油气优势路径分布叠合，研究油源断裂输导油气优势路径演化形式。再结合油源断裂附近油气分布，阐述油源断裂输导油气优势路径演化形式与油气分布关系。.本项目经过4年基础攻关研究取得了以下3个创新研究成果：①基于断裂古活动速率和地层脆塑性，建立了一套活动期油源断裂输导油气优势路径的识别方法，较以往仅基于断裂古活动速率识别油源断裂输导油气优势路径有所创新；②基于断裂填充物泥质含量和填充物输导油气所需的最大泥质含量，建立了一套停止活动后油源断裂输导油气优势路径的识别方法，较以往基于断层面古油气势能等值线法线汇聚线识别油源断裂输导油气优势路径有所创新；③基于活动期和停止活动后油源断裂输导油气优势路径之间的变化特征，建立了一套油源断裂输导油气优势路径演化形式的研究方法。.本项目对指导含油气盆地下生上储式油源断裂附近油气勘探具有重要指导作用，还可以丰富和完善断裂控藏理论。