【摘要】 复杂的相态变化特点决定了凝析气藏渗流研究比常规气藏具有更大的难度和特殊性。已有凝析气藏油气分布模型均以稳态法或非稳态法测得的相对渗透率为基础,因未考虑凝析液堵塞作用,从而高估凝析油渗流能力,导致结论与现场实际生产情况存在一定偏差,不能准确描述储集层内油气分布规律和正确评估气井产能。目前基于储集层微观非均质性的凝析气藏不同生产阶段油气分布规律的研究较少,缺乏制定气井全周期生产制度的必要理论依据。鉴于此,引入能反映凝析气藏内流体渗流能力的拟稳态相对渗透率测量方法,根据气藏微观孔隙尺度及毛细管压力分布,结合气井不同生产阶段油气渗流特征,形成一套开发全过程油气分布特征描述方法。并将该方法应用于凝析气藏生产参数优化设计,认为凝析气藏开采后期采用大压差生产时,应重点考察拟稳态相对渗透率对油气采出动态的影响,最后通过实际凝析气井的生产动态验证了提出的观点。更多还原

【Abstract】 The percolation research of condensate gas reservoir has its particularity and is more difficult than that of conventional reservoir due to the intricate phase variations.The existing oil and gas distribution models for condensate gas reservoir are based on relative permeability curves measured with steady-state or unsteady-state methods,which does not consider the blocking of condensate liquid and may overestimate the filtration capacity of the condensate oil,resulting in certain deviations between the model results and the actual production status in the field,so the models can’t accurately describe the oil and gas distribution in reservoirs and evaluate the productivity of gas wells.Moreover,there are few studies on the oil and gas distribution in condensate gas reservoirs at different development stages based on reservoir microscopic heterogeneity so that there is no necessary theoretical basis for full-cycle production system making for gas wells.In view of this,a relative permeability measurement method of pseudo steady-state which can reflect the filtration capacity of fluids in condensate reservoirs is introduced to establish a set of full-process methods for oil and gas distribution description according to reservoir microscopic pore size and capillary pressure distribution and combined with the oil and gas filtration characteristics at different production stages in gas wells.The methods are applied in the optimal design of production parameters for condensate gas reservoirs and the results show that the influence of pseudo steady-state relative permeability on oil and gas production performance should be highlighted when large pressure difference is adopted in the condensate reservoirs at the late production stage,and finally the proposed methods are validated by the actual production performance in condensate gas wells.更多还原