腰英台地区钻井完井液保护油气层效果评价

腰英台区块地处松辽盆地南部长岭凹陷东北部,储层属低孔特低渗油气藏,具有中等偏弱速敏、弱水敏、中等偏强酸敏等特点,水锁损害程度属中等偏弱.为了保护油气层,减小储层伤害,选用了两种钻井完井液体系:两性离子聚合物钻井液体系和聚合物腐钾聚合物钻井液体系.实验表明:两种聚合物体系的各种处理剂与地层水的配伍性好,储层岩心的动态渗透率恢复值在80%以上.现场测试也表明,这两种钻井完井液体系对腰英台区块复杂油气层保护效果较好.

Reservoir protecting performance evaluation on drilling/completion fluid for Yaoyingtai wellbock

Yaoyingtai block is located in northeast part of Changling sag, south to Songliao Basin. It is a low porosity and ultra-low permeability reservoir, which is medium but slight weak velocity sensitive, weak water sensitive, medium but slight strong acid sensitive and medium but slight weak water-shut in sensitivity evaluation. In an effort to protect oil/gas reservoir and reduce damage to formation, two drilling/completion fluids were selected, which are, zwitterionic polymer drilling fluid and potassium humate/ polymer drilling fluid. Tests results showed these two fluids have good compatibility with formation fluids, and the dynamic permeability recovery of reservoir rock was more than 80%. In-situ tests also illustrated the excellent reservoir protection effect of these two fluids.