鱼骨状分支井数值模拟井指数计算方法研究

随着钻完井技术的不断提高,鱼骨状分支井得到了越来越广泛的应用,但是在对鱼骨状分支井进行数值模拟时,常规的井指数计算方法难以适应模拟复杂井形的需求。针对鱼骨状分支井井筒间严重的干扰影响和复杂的渗流关系,在井指数定义式的基础上,结合鱼骨状分支井解析模型与数值模拟稳态模型,充分考虑油藏各向异性的影响,提出了新的鱼骨状分支井井指数计算方法。在新的井指数计算方法的基础上,对鱼骨状分支井进行了井形参数优化研究。结果表明,分支数目较少时,可以选取较大的分支长度,反之,分支长度则不应过长;分支数目应不小于4个,当分支长度小于50m时,增大分支数目的增产效果不明显;分支角度应不小于45°。

Research on Calculation Method of Well Index for Numerical Simulation of Herringbone Branch Wells

With continuous development of drilling technology,herringbone branch wells were widely used.But for the conventional herringbone branch well numerical simulation,conventional calculation method of well index could not meet the demands of modeling of complex well simulation.According to the complex flow relationships and serious interference among branches of herringbone wells,a new calculation method of well index for herringbone branch wells was proposed based on the definition of well index.The new method is a combination of analytical model and stable numerical simulation model for herringbone branch wells,and it can take full account of anisotropy.Based on the new calculation method of well index,the structure of herringbone branch wells is optimized.The result indicates that larger lateral length should be selected when lateral number is relatively small,and vice versa.Lateral number should be more than four and lateral angle should be more than 450.At the same time,when the lateral length is less than 50 meters,no obvious effect of increasing lateral number is obtained.