水平井两相流变密度射孔模型研究

Study on variable density perforating model of two-phase flow in horizontal wells

综合考虑水平井气液两相流体分层流动特性以及气液两相流体高速通过射孔孔眼所产生的非达西流动效应等因素,基于向井流流动模型和水平井筒气液两相分层流动模型,建立了水平井两相流变密度射孔优化模型。通过对所建模型的数值求解,揭示了变密度射孔完井水平井内气液两相分层流动规律,并对模型中产量、地层渗透率等重要参数进行了敏感性分析。结果表明,均匀射孔会导致水平井筒跟端的径向流入量大大增加,出现明显的端部效应,而通过调节射孔密度,可以有效地调整水平井生产剖面,尤其对于高渗油藏,变密度射孔能够有效地减缓可能出现的水气锥进,从而提高油田的开发效益。

On consideration of the characteristics of gas-liquid two-phase stratified flow in horizontal wells and the non-Darcy effect which was caused by high speed gas-liquid two-phase flow through the perforation, an optimization perforating model with variable density of two-phase flow was established on the basis of the inflow model to the well and the gas-liquid stratified flow model in horizontal wells. The gas-liquid two-phase stratified flow law was revealed and the sensitivity of production and permeability was analyzed by numerical calculation. The results show that uniform perforating results in the increase of inflow at the heel of horizontal well. The horizontal well production profile can be controlled efficiently by means of perforation density adjustment especially in high permeability reservoir. The water and gas cone can be mitigated and the development benefit of oilfield can be increased through variable density perforating.