水平井分段酸化后表皮因子研究新方法

水平井封隔器分段酸化技术作为各向异性油气藏中实现均匀酸化的一种重要增产措施，因而均匀酸化后表皮
因子的研究变得至关重要。以水平气井井筒周围椭圆形污染带为基础，考虑酸液均匀改造污染带以及残酸返排对气
体渗流的影响，将椭圆形伤害带内复合区域渗流问题划分为3 个均质区域内流体的渗流，利用阻力叠加原理获得计算
水平气井分段酸化后表皮因子新方法。实例分析表明：水平气井分段酸化后局部表皮因子沿井筒方向由跟端到趾端
不断减小，且随着酸化半径以及酸化带渗透率的增大不断减小，而随着泥浆垂向最大浸入半径的增大而增大。研究为
水平气井分段酸化表皮因子计算提供了一个新思路。

New Method to Study the Skin Factor of Horizontal Gas-well After Staged Acidizing

Horizontal well staged acidizing with packer has been an important stimulation treatment to achieve uniform acidizing
in anisotropic reservoir，so the study of skin factor after staged acidizing is of great importance. Based on the elliptic
damage zone near the horizontal gas well，the authors take by into consideration the uniform treatment by acids and influence
of residual acid back flow on gas flow in the reservoir，and dividing the flow problem of composition area in elliptic damage
zone into three flow problems in homogeneous region，taking advantage of resistance superposition theory，we eventually get a
new method to calculate the skin factor of horizontal gas well after staged acidizing. The case study shows the local skin factor
of horizontal gas well after staged acidizing becomes smaller from the heel to toe-end along the direction of wellbore；it also
decreases with the increase of acidifying radius and permeability of acidizing zone，but increases with the increase of maximum
immersion radius. The study in this paper will offer an new approach to the calculation of the skin factor of horizontal gas well
after acidizing.