准噶尔盆地凝析气藏压井液体系的研制应用与集成

KILLING-FLUID SYSTEM FOR CONDENSATE GAS RESERVOIRS, JUNGGAR BASIN

准噶尔盆地凝析气藏储集层存在岩类多、物性差异大,敏感性强,地层压力系数分布范围广、变化大等问题。为降低修井作业中压井液对储集层的伤害,提高修后复产效果,根据凝析气藏特征和不同开发阶段修井作业储集层保护的需要,相继研制了无固相有机盐、防水锁树脂、暂堵型凝胶三种压井液体系。通过实验评价,性能均满足并优于《SY/T 5834-2007低固相压井液性能评价指标及测量方法》要求。累积应用62井次,气井修后总体复产率高于85%。结合压井液技术特点与应用效果,确定了三种压井液体系的适应范围。以地层压力系数及孔渗大小为横、纵坐标轴,建立了压井液的技术界限模版,实现了压井液体系的集成。

With variable formation-pressure coefficient, most condensate gas reservoirs,which are widely distributed in Junggar Basin, are characterized by various rock types, poor petrophysical property, and high sensitivity. To reduce reservoir damage from killing fluid during a workover and improve restoring production, according to both reservoir characteristics and reservoir-protection requirements during different development stages, three systems of killing fluid including solid-free organic salt, water-block prevention resin and temporary plugging gel have been developed. An experimental evaluation shows that their performance can meet the requirements of SY/T 5834-2007 Evaluation Index and Measurement Method of Performance of Low-solid Killing Fluid. Their application to 62 well times indicates that the restoring production rate after the workover is higher than 85%. Based on technical features and application effect of killing fluid, the system scopes are determined. Moreover, taking the formation-pressure coefficient and the porosity and permeability as the axis of abscissa and ordinate respectively, we have developed a technical limit template of killing fluid to realize an integration of killing fluid systems.