水平井与直井混合注采井网的流场计算——以五点法注采井网为例

Calculation of Flow Field in Mixed Injection Production Well Pattern of Horizontal Wells and Vertical Wells:Five Point Injection Production Pattern

基于保角变换和镜像反映原理,建立五点法水平井与直井混合注采井网流场数学模型,导出其势函数和流函数数学表达式,得到五点法混合注采井网内部等势线和流线分布.研究水平井长度、水平井与直井连线夹角、平面各向异性及水平井不同平面位置等因素对混合注采井网内部流场分布的影响.结果表明:混合注采井网水平井跟端和趾端,流线分布相对密集,两端位置产液能力较强;水平段越长,其流线控制的泄油面积越大;水平井与直井连线成45°角时,水平井与正对的两口直井间的驱替强度相对较大;水平井垂直于主渗透率方向时,流线均匀密集地汇聚到生产井,易形成线性驱替;混合注采井网内部水平井偏离中心位置程度越大,流线分布疏密分化越明显.

With principle of conformal transformation and mirror reflection, a mathematical model of flow field in a mixed injection production well pattern was established. Five point horizontal well and vertical well pattern are used for an example. Mathematical expressions of potential function and stream function are derived. Distribution maps of potential line and flow line in a mixed injection production well network with five point method are obtained. Influence of key parameters on internal flow field distribution of mixed injection production well network is analyzed. It shows that at both ends of horizontal well flow lines are relatively dense, and liquid producing capacity at both ends is stronger. The longer the horizontal section, the greater the discharge area of flow line control. As horizontal well is 45 degree angle with vertical wells connection line, displacement effect of horizontal well is relatively good. As horizontal well is perpendicular to direction of main permeability, streamlines are concentrated to production well. Linear displacement is formed and the displacement effect is good. As horizontal well is off center position greater, streamline distribution density differentiation is more obvious.