白豹地区长6油层组湖底滑塌浊积扇沉积特征及意义

Characteristic and Significance of Lake Bed Slump Turbidite Fan Sedimentation of Chang6 Oil Reservoir Group in Baibao Area

上三叠统延长组长6段是白豹地区最重要的勘探目的层之一，其沉积相类型及其对砂体展布及油气储层的控制等开发地质问题的研究倍受重视。本文在岩心和测井分析基础上，结合铸体薄片、扫描电镜、微量元素、孔渗分析等大量室内测试资料对白豹地区长6油层组沉积体系类型及特征进行了深入研究，首次提出白豹地区长6油层组属于湖底滑塌浊积扇沉积体系，岩性以成分和结构成熟度均偏低的微-细粒长石砂岩为主，具粒序层理、液化包卷层理、滑动截切和变形构造、小型同生断层、槽模、沟模和重荷模等浊积沉积相标志。在浊积扇岩相组合、沉积序列及平面演化特征分析的基础上，结合区域地质背景，探讨了湖底滑塌浊积扇的成因机制，建立了相应的沉积模式，最后分析了其在长6油藏开发工程中的意义。

The types and characteristics of sedimentary system of Chang6 oil reservoir group in Baibao area are deeply studied on the basis of core and well log analysis, and combining with plenty of lab test data such as cast thin section, SEM, trace elements, porosity and permeability analysis, etc. The authors firstly put forward that Chang6 oil reservoir group in Baibao area belongs to lake bed slump turbidite fan sedimentation system. The lithology takes micro-fine granular feldspar sandstone with slightly low maturity of beth composition and structure. The group has a turbidity sedimentation facies symbol of grain sequence bedding, liquefaction convolute bedding, slip surface of scour and deformation structure, small contemporaneous fault, flute cast, groove cast and load east and so on. On the basis of turbidite fan petrofacies combination, sedimentary sequence and plane evolution characteristic analysis, the genetic mechanism of lake bed slump turbidite fan is discussed, integrating with the regionally geologic background. The corresponding depositional mode or pattern is established. Finally the authors analyze its significance in the Chang6 oil reservoir development engineering.