大港千米桥凝析气藏低密度压井液的应用  

Application of low density killing fluid in Qianmiqiao condensate gas reservoir, Dagang

作　　者：郑淑杰[1] 钟惠敏[1] 李洪俊[1] 周玉新[1] 黄义坚[1] 

机构地区：[1]大港油田钻采工艺研究院

出　　处：《钻井液与完井液》2003年第6期60-61,共2页Drilling Fluid & Completion Fluid

摘　　要：大港油田千米桥潜山碳酸岩储层地层压力系数已下降到了0.84～0.90,储层温度为165.5～167.9℃.有很强的压力敏感性和水敏性。使用的水基压井液密度均大于1g/cm^3.洗井时经常有压井液漏失,对水锁严重的千米桥潜山储层损害严重。室内实验结果表明.现场使用的压井液对渗透率小于10×10~3。μm^2。的气层存在比较严重的损害,其原因可能是压井液滤液进入低渗岩心的细小孔喉,引起水锁损害造成的;对渗透率大于10×10~3μm^2。的岩心,渗透率恢复值在95％以上。研究出了抗高温乳化剂DR-4和低密度抗高温水包油压井液体系.该压井液密度为0.84～0.90 g/cm^3,在168℃下老化48h不破乳;岩心损害后的渗透率恢复值大于87.6％;具有良好的抗地层水、凝析油污染能力,抗污染容量为1O％;闪点高达80℃,可保证施工安全。Strong pressure sensitivity and water sensitivity exist in Qianmiqiao buried hill carbonate reservoir where the pressure factor has dropped to 0.84~0.90, and the temperature has been 165.5~ 167.9℃.Due to the use of water-based killing fluids with density of higher than 1 g/cm3 , it often lost during well-flushing that lead to serious formation water block damage.Laboratory experiments showed that used present killing fluid in less than 10×10-3μm2 permeability gas reservoir would lead to severe damage because the possible reason of the killing fluid filtrating into low permeable core pore throat leading to water block; in more than 10×10-3μm2 permeability core, the permeability recovery value would reach above 95%.An anti-emulsifying agent DR-4 and a low density oil in water killing fluid system have been developed.The density of the fluid is 0.84~0.90 g/cm3 and it can not be de-mulsified in 168℃ for 48 hours; by using it, damaged core permeability recovery value reaches over 87.6%.Since the killing fluid also has better abilities of anti formation water and condensate oil with 10% of condensate oil contaminations and 80℃ of flash point, it can ensure killing safety.

关 键 词：大港油田 千米桥潜山 凝析气藏 低密度压井液 地质 油气保护 

分 类 号：TE254.4[石油与天然气工程—油气井工程]