裸眼系列完井方式下鱼骨井产量模型求解方法

A model solution for herringbone well under open hole completion system

为了向鱼骨井完井方案设计提供必要的理论参考依据,建立了鱼骨井产量稳态耦合模型,以裸眼系列完井方式为核心内容,以微元段法为求解手段,定量阐述完井筛管对耦合流动过程的影响,得到了鱼骨井流压分布剖面和流率分布剖面。经分析认识到,完井筛管管外环形空间储层砂堆积层产生的渗流附加压降影响了油藏渗流,井筒流压和流率分布剖面相对于裸眼完井整体下降,影响程度主要取决于储层砂粒度中值和筛管挡砂精度,同时也受到渗流干扰作用的局部控制;完井筛管尺寸、管壁质量交换效应以及基管孔眼参数影响了井筒管流,使得全生产井段井筒流压分布剖面相对于裸眼完井更加陡峭。通过与经典产量解析模型对比计算,证明了本文模型的合理性。

A steady state coupling model combining seepage flow and pipe flow was established for herringbone horizontal well, which will provide fundamental theory reference for completion design of complex structure wells. This model focused on open hole completion system and was solved by infinitesimal section method. Each part of pressure drop in coupling flow with existence of completion screen pipes was discussed in detail, and then the flowing pressure and flow rate distribution profiles were given. The analysis results show that, formation sand stack layers in annular space between screen pipes and wellbore produce an additional pressure drop, which make a negative influence on the seepage flow. The flowing pressure and flow rate distribution profiles of wells with screen pipe are lower than those of open hole under the same flowing pressure, and the affection degree primarily depends on sieve size of screen pipe as well as formation sand grain distribution, and partly controlled by local seepage interference. The size of screen pipe, parameters of eyeholes in base pipe and mass transfer in pipe wall have an effect on well bore flow, which makes wellbore flowing pressure dis- tribution profile of overall production section is steeper than that of open hole under the same proration production. By comparing the calculated results with the classical model solutions, the model proposed in this paper is proved reasonable.