摘要
通过坐标变换,将各向异性油藏变为等价各向同性油藏,井网单元及井筒形状都同时改变;再通过保角变换,将从等价各向同性油藏中任选的一个矩形井网单元变成一个椭圆形区域,注水井筒变成椭圆形定压边界,将水平井映射到椭圆形区域的中央位置。利用椭圆形区域流动问题的已知解,得到各向异性油藏整体水平井网的渗流解,给出了压力分布公式和流线分布图。在水平井筒和注水井排平行于各向异性渗透率最大主方向的情况下,五点面积井网渗流和产能的特点为:①渗透率各向异性程度增强,井网的单井产能减小,扫油体积系数增大;②渗透率各向异性程度较强时,井网单元内的流线呈现平行渗流特点;③渗透率各向异性程度越强,主流线突破点离水平井端点距离越远。
By using coordinate transformation, an anisotropic reservoir can be mathematically modeled as an isotropic reservoir, and the morphology of a well-bore and a well network have therefore also been conceptually modified. With Elliptical Cosine conformal transformation, each rectangular unit of a well network is modeled to an ellipse. The isopressure boundary of a well-bore therefore becomes an ellipse and a horizontal well is projected to the center of this ellipse. The flow pattern, pressure distribution, and flow intensity of a given anisotropic reservoir can be derived from the known elliptical flow pattern. When anisotropy of permeability increases and the prevailing permeability becomes parallel to the well alignment in a network, the permeating flow and production in a 5-point well network with anisotropic permeability have the following characters: ① the productivity is inversely proportional to the anisotrophy of permeability;② the flows becomes closer to parallel when the anisotrophy of permeability increases; and ③ the distance between the breakthrough point of injected water moves further away from the end of a horizontal well network.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2004年第1期94-96,共3页
Petroleum Exploration and Development
基金
中国石油天然气集团公司研究项目(990509 02 06)
关键词
矩形区域
复杂流动
线性变换
保角变换
解析解
anisotropic permeability
rectangular area
complex flow
coordinate transformation
conformal transformation
