砾岩低渗透油藏注水开发后期流动单元研究

【作者】 胡新平；

【导师】 李允； 闻玉贵；

【作者基本信息】 西南石油学院 ， 石油与天然气工程， 2005， 博士

【摘要】 流动单元的提出从油藏地质角度进一步解剖和精细刻画出层间、平面和小层内部及孔喉规模上的储层非均质特性;同时也表征出了流体在储层中运动的轨迹和差异,是储层地质与油藏开发动态有机结合的桥梁和纽带。其井间对比及空间结构问题更需要露头和现代沉积的精细研究及随机建模予以解决。在这些综合交叉科学研究和庞杂的技术系列工程中,本文选择准噶尔盆地西北缘砾岩低渗透攻关难题,从注水开发后期要解决的实际矛盾出发,突出实用性是关键,探索出了一套适合本地区油藏地质特点的流动单元研究理论和技术方法,不断地向砾岩低渗透油藏极限采收率挑战。 块状非均质砾岩油藏注水开发要比层状砂岩油藏复杂得多,低渗透非线性渗流注水开发难度大,因此开展砾岩低渗透油藏流动单元研究目前在国内外尚处于前缘性研发阶段。在跟踪分析近20年国内外流动单元研究方面最新动态的基础上,本文认为流动单元是介于静态地质和油藏动态的交叉学科,必须考虑流体因素,等渗流特征是最基本性质,而不仅仅是沉积微相研究和储层评价,只有将流体性质和外部采油工艺措施条件引入其中,才能反映出目前油水在储集体空间上的渗流差异。因而论文从流动单元细分与对比、边界条件研究、研究的技术方法、分类与评价、建立流动单元模型和应用综合阐述。每一部分强调动态与静态结合,将静态地质融于动态分析之中,动态结果反过来验证静态地质认识,最后突出流体在储层中渗流的差异。 与国内外同类技术相比,论文中突出侧向叠加复合砾岩体单一河道识别;图像分形几何学用于流动单元表征、利用毛管压力曲线R35微观孔隙结构参数研究流动单元;井间连通体等渗流特征对比等方法技术。 通过砾岩低渗透流动单元的综合研究,取得以下结论: 1)储层自身条件、边界条件、流体条件和采油工艺措施等外部条件是评价流体在孔隙岩石中流动性能的四个条件; 2)岩相单元的细分与对比是流动单元研究的重要基础,岩相单元、非均质单元和流动单元三者紧密相关,但又不尽相同。沉积间歇面的提出为流动单元的纵向细分和横向对比提供了沉积学依据; 3)流动单元的方向性很明确,是一个矢量地质参数,这主要取决于沉积储层和构造条件,表现在渗透率的双重各向异性上,三维连续储集体上流动单元的差异是造成水驱油效率差异的主要原因,直接影响着陆相非均质油藏注水开发效果; 4)五2西克下组油藏可划分为四种类型的流动单元,在研究区块状砾岩体低渗透三维更多还原

【Abstract】 The views of flow unit point out that heterogeneity of reservoirs should be deeply studied and interpreted in terms of reservoir geology, from interbed, latitude and thin-layer to pore-throat. They can also be used to pose the orbits and differences of reservoir fluids. So the study of flow unit is a bridge connecting reservoir geological characteristics and dynamic oil developments. The inter-well-contrasting and frame-building are depended on delicate study of modern sediments and random modeling. Out of large number of studies on the synthetic interdisciplinary and so much technological engineering, this article chooses the puzzling project for low permeable conglomerate reservoirs of Northwest Bounder in Jungaer Basin. Based on existing contradictions during later period of waterflood recovery, we find a sort of theories and skills of flow unit, which are suitable to reservoir geological characteristics, and we are challenging continuously the oil recovery limit of low permeable conglomerate reservoirs.Due to the heterogeneity of low permeable conglomerate reservoirs, the waterflood development of reservoir is much more complex than layered sandstone reservoir. Waterflood development of low permeable nonline reservoirs is very difficult, so study of flow unit for low permeable conglomerate reservoirs may be in advancing edge. Beyond the latest research of flow unit at home and abroad recent 20 years’ research, this article advances that study of flow unit is out of a new interdisciplinary between static geology and dynamic reservoir engineering. We must concern the fluid factors, and realize that equal influent feature is the most basic character. The study is not limited to division of sedimentary microfacies and evaluation of reservoirs; only when fluid features and outer oil recovery techniques are included, it could show the influent differences of oil and water in the space of reservoirs. Therefore, the contents of this article are widely involved high division and contrast of flow unit, study of bounder conditions, the techniques and methods of the study, classification and evaluation of the study, building of flow unit model and utilization of flow unit. Each part stresses the binding of static and dynamic data, and pays attention to the influent differences of reservoir fluids.based on the studies of flow unit for low permeable conglomerate reservoirs, the follow conclusions are derived:1) four factors using to evaluate flow ability of subsurface fluids are natural condition, boundary condition, fluid condition and outer conditions of oil recoverytechniques;2) subdivision and contrast of lithofacies unit is the important base of the study of flow unit, and lithofacies unit, heterogeneity unit, and flow unit are not same but tighly relative, what’s more the raise of sedimentary pause surface provides sedimentary references to vertical subdivision and lateral contrast of flow unit;3) flow unit, a geologic vector, has definite direction, which mainly is controlled by sedimentary and tectonic conditions of reservoirs, and the direction is expressed as twofold anisotropy, and then the difference of flow unit in 3D connective reservoirs controls mainly the difference of waterflood efficiency, meanwhile it directly influences the effectiveness of waterflood oil recovery for continental heterogeneous reservoirs;4) West Wu2 Reservoirs of Lower Kuramay Fm.^k1) can be divided into four types of flow units, and their difference is the main reason for differences of waterflood efficiency for these 3D connective oil beds of block low permeable conglomerate reservoirs.5) with resolves of flow unit, we can judge lateral conformance effective of water flood, analyze vertical water out degree, anticipate drawdown, prospect the distribution of remnant oil, and provide overall reservoir static and dynamic models for reservoir numerical simulation, so it raises a important way for improving oil recovery during latter period of oilfield development.更多还原