基于分形几何的裂缝型底水气藏产能模型  

Productivity model of fractured bottom-water gas reservoir based on fractal geometry

作　　者：黄小荷[1] 朱维耀[1] 岳明[1] 刘今子[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]东北石油大学数学科学与技术学院,黑龙江大庆163318

出　　处：《东北石油大学学报》2013年第6期86-93,10,共8页Journal of Northeast Petroleum University

基　　金：国家重点基础研究发展计划项目(2013CB228002)

摘　　要：针对现有裂缝模型多采用均质或拟均质假设处理方法,不能反映实际复杂裂缝结构,引入分形几何的方法描述裂缝网络,推导分形裂缝储层的渗透率公式.基于底水油气藏双重不完善井的复杂渗流模式,即直井射孔段上部为水平径向流,射孔段下部为半球形向心流,将其推广到水平井,认为水平井以上为半椭球流,水平井以下为半圆柱形向轴心流,分别推导裂缝型底水气藏直井和水平井产能公式.应用结果表明:裂缝和生产井与气水界面的距离对产能的影响为缝宽分形维数越大,直井和水平井产能越大;气藏打开程度越大,直井产能越大;水平井距底水越远,水平井产能越小.The present fracture models are usually dealing with a homogeneous or pseudo-homogeneous assumption,which can hardly reflect the complicated fracture structures in practice.Therefore,the method of fractal geometry has been introduced to describe fracture network.In the paper,introducing fractal geometry to the description of fracture network,a mathematical model for productivity of bottom-water vertical gas reservoir is established,assuming that flow is planar radial flow in the upper part of perforation section,and hemispherical radial flow in the lower part.Assuming that flow is elliptical flow above wellbore,and cylindrical radial flow below wellbore,productivity equation is derived for horizontal wellbore.The model simulated the effect of fracture and distance between wellbore and gas-water interface on productivity.Numerical results show that the larger the fractal dimension of fracture width,the later the productivity.In addition,with larger perforation degree,production of vertical well will increase.Greater distance between horizontal wellbore and bottom water leads to smaller production.

关 键 词：分形 裂缝 底水气藏 产能 

分 类 号：TE312[石油与天然气工程—油气田开发工程]