特低渗透砂岩油藏精细描述及数值模拟研究应用

【作者】 程启贵；

【导师】 李允； 王道富；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2006， 博士

【摘要】 中国陆上已探明未动用储量中有一半以上是特低渗透储量，必须总结并完善特低渗透油田油藏精细描述及数值模拟实用技术。 特低渗透油田油藏精细描述及数值模拟技术是油藏精细描述及数值模拟技术更深层次的问题。特低渗透油田天然裂缝和人工裂缝，它既是增加导流能力的有利因素，又是引起水窜的不利因素。研究描述裂缝发育规律性、研究井网与裂缝方向的适应性、研究适合特低渗透油藏模拟模型参数场及可调幅度等，是特低渗透油田数值模拟技术的关键。流动单元的精细划分是解决储层剖面多层流动产量如何分配问题的方法。湖相三角洲沉积采用模糊聚类与模糊识别相结合的方法，对流动单元进行分类效果较好。本区划分出A、B、C、D四类流动单元。建立起流动单元类型与沉积相带、储渗能力的关系。特低渗透油田储层非均质性更强。储层参数的空间变化规律的把握是油藏模拟模型建立的关键。 本文以鄂尔多斯盆地五里湾油田为例研究探讨特低渗透油田油藏精细描述及数值模拟方法和技术。砂体结构模型采用了离散随机模型，通过“相控建模”建立储层参数分布模型。使用GOCAD建模软件，将变异函数与相关函数等应用到建模过程中。同时应用确定性信息来限定随机建模过程。用于岩石物理参数建模的随机模型，采用了序贯高斯模拟进行储层参数的随机模拟。 为了控制地质体的形态，保证建模精度，设计模型网格为25m×25m×0.5m，计496×532×110=29，025，920个网格。根据分层数据资料，利用GOCAD建模软件得到层面模型模块。三维构造模型共5个层6个层面构造层面模型。 油藏数值模拟模拟精度及经济要求，粗化网格平面网格距离设计为50m，纵向网格平均距离为3m，网格总数为：247×265×23=1，505，465。 孔隙度型数据采用算术平均方法网格粗化，渗透率型数据采用几何平均方法网格粗化。从五里湾油田原始井数据及粗化前后储层参数的直方图对比效果来看，模拟数据很好地恢复了原始参数的分布，粗化结果参数分布也与模拟数据保持一致，可见，模拟结果和粗化结果是合理可信的。 特低渗透砂岩油藏数值模拟不同于其他油藏数值模拟，主要在于：一是特低渗透砂岩储层特征描述是否细致准确；二是储层非均质性及其渗流特征的复杂性是否认识到位；三是特低渗透砂岩油藏地质模型是否真实反映地质特点；四是储层模型关键参数场研究如渗透率、裂缝处理方式是否得当。 建立油藏模型是决定历史拟合和动态预测成败的关键。数值模拟的初始地质模型，还要通过生产史的拟合对模型进行部分调整，使地质模型更加完善。参数的调整要符更多还原

【Abstract】 The Chinese land has clearly explored the unused oil reservoirs is more than a half of low permeate oil reservoirs, we have to summarize and consummate meticulous description on low permeate oil-field reservoirs as well as numeral simulation technique.The meticulous description and numeral simulation on low permeate oil-field reservoirs is a deeper problem on oil reserves meticulous description and numeral simulation. Natural fissure and manual fissure is not only a good factor to raise mobile capacity, but also a bad factor to lead to inundation. The key point on low permeate oil-field reservoirs is to research and descript on fissure growth regular, to research on well net and fissure orientation’s adaptation, to research on low permeate oil reservoirs imitation model’s parameters and adjusting range. Mobile unit meticulous dividing is to solve how to distribute cross section’s multi layer mobile output. Lake faces delta sediment is good use fuzzy clustering and blur identification method to classify mobile unit. This borough has classified four mobile unit(A ,B ,C,D) , has established mobile unit’s types and sedimentary faces, has fixed on connection between reposition and permeation. Low permeate oil-field’s container rock has stronger lack of homogeneity. How to master reserve space’s changing regular is a key to establish oil reserves simulation model.This paper takes Erduos basin’s five inner bay for example, we research on low permeate oil reservoir’s meticulous description and numeral simulation technique. Ore mass structural model is discrete random model, it is adopted faces controlling model technique to establish reservoir parameter distributing model. We use GOCAD establishing model software, apply variation function and correlation function to this model and take clarity information to restrict modeling process. Rock physic parameter’s random model that is Gauss simulate its reservoir parameters.In order to control geologic body configuration and ensure modeling precision, we adopt grid mode is 25m×25m×0.5m,it sums to 496×532×110=29025920 grids. According to individual-layer data, we use GOCAD modeling software to get layer model. Three dimension has 5 layer and 6 layer construct model.To attain oil reservoirs numeral simulation precision and economical demand, we use 50m between them, portrait grid average distance is 3m, total grids are 247×265×23= 1505465.Porosity data takes arithmetic average method to wide grid, percolation rate data takes geometry average method to wide grid. From the five inner bay oil-field originality well data as well as wide before and end reservoir parameter’s histogram contrasting, we can see simulation data do a good resume to original parameter’s distributing, wide result’s parameter is consistent to simulation data. So, simulation result and wide result are in reason.Unusual low permeate sand stone’s oil reservoirs digital simulation is different to others. There are four reasons: the first is whether to meticulous depict unusual low permeate sand stone oil reservoir, the second is whether to realize oil reservoir’s lack of homogeneity and更多还原