水平井河道砂体内部构型及对三次采油期剩余油形成机制研究

With Oilfield entered the tertiary phase from water injection development, study on reservoir from the monosandbody into the architecture of monosandbody. A small number of horizontal well drilled at this time and its core provide excellent conditions for thorough research on the horizontal rule and mode of the monosandbody architecture and remaining oil. Previous research found that there are several interbeds in monosandbody and they have an important influence on heterogeneity, the injectant driving oil, and the generation of remaining oil in monosandbody. But these interbeds are very thin(＜30cm),narry, unstable, uneasy trace and contrast between wells, moreover because of along-layer of horizontal well, great changes of geological structure in and around well, logging environment, logging response characteristics, depositional sequence along well cause the interbeds of difficult resolution in logging, difficulty forecastion to scale, uncertainty of architecture, to come here, How to establishe the interbed architecture model of underground monosandbody in horizontal well area? How to predict spatial distribution of thin interbeds? What is the formation mechanism and distribution law of remaining oil controlled by different reservoir architecture? Focusing on the scientific issues, plans by the reservoir architecture model as a guide, our study will use the level analysis method, the combination of modern sedimentation, ancient outcrop, underground monosandbody, indoor flooding physical simulation, horizontal well and vertical well, integrated research on core, logging, dense well group and river engineering parameter, establish the corresponding reservoir architecture model and prediction method, explore the mechanism of its formation.

随着老油田由注水开发转入三次采油期，储层研究也由单砂体深入到单砂体内部构型。此时的少量已钻水平井及岩心，为深入研究单砂体构型、剩余油的横向规律与模式提供了极好条件。前期研究发现，单砂体内部存在多个薄夹层，且其对单砂体非均质性、注入剂驱油、剩余油形成有重要影响。但该类夹层极薄(﹤30cm)、规模小、稳定性差，直井间难追踪对比；加之水平井的沿层性，又使井筒及周围地质体组构、测井环境与响应、沿井沉积序列等发生较大变化而造成夹层的测井难分辨、规模难预测、构型难确定等难点，至此，如何建立水平井区地下单砂体内部薄夹层构型模式？薄夹层如何预测？不同构型对剩余油形成与分布的影响与控制机理？着眼于上述科学问题，拟以储层构型模式为指导，采用层次分析方法，现代沉积、古代露头、地下单砂体、室内物理模拟互鉴，水平井与直井结合，岩心、测井、密井组、河流工程参数等综合研究，建立相应的构型模式、预测方法，探索其形成机理。

结题摘要: 该项目在“老油田由注水开发转入三次采油期，水平井、加密井渐增，储层研究也由单砂体深入到单砂体内部构型、剩余油复杂难预测”等背景下，针对“单砂体内部存在多个极薄(﹤30cm)、规模小、稳定性差，直井间难追踪对比；加之水平井的沿层性，又使井筒及周围地质体组构、测井环境与响应、沿井沉积序列等发生较大变化而造成夹层的测井难分辨、规模难预测、构型难确定”等难点，以大庆长垣杏六区东部、北一区西部等葡Ⅰ组主力油层河道砂体为重点靶区，并结合大庆长垣外围的肇州油田南一区葡萄花油层、榆树林油田东141区块扶杨油层等，开展了水平井河道砂体内部构型及对三次采油期剩余油形成机制研究，取得了“水平井岩心3级校正归位、测井校正及岩性测井识别；水平井/直井单河流期短期基准面旋回层序平面沉积微相及单砂体识别；水平井/直井地下单砂体内部薄夹层构型及空间预测；平直井‘构型控’河流单砂体内部物性格架、三维非均质性模式及建模；河道单砂体内部薄夹层及构型控制的三次采油期剩余油分布模式”5项主要成果，其对水平井区储层内部构型及剩余油分布模式研究具有较重要的科学意义，对老油田后期调整、三次采油期精细地质研究具有重要实际意义。