【摘要】 吐哈油田部分区块地层压力系数小于0.9,常规水基压井液对储层伤害大,若使用油基压井液成本高,环境污染严重。通过实验优选出了一种低密度水基微泡沫压井液。该压井液具有密度低、泡沫强度高、稳定性好、携砂能力强等优点。现场应用表明,低密度微泡沫压井液稳定时间大于48 h,密度在0.70~0.99 g/cm3之间可调,抗油污染能力强,抗油大于8%,抗温在100℃以上,岩心污染后渗透率恢复值大于80%;并且施工方便,成本低,具有储层保护能力,使用微泡沫压井液的井表皮系数在0.20~2.34之间。更多还原

【Abstract】 Formation pressure coefficients of some blocks in Tuha oilfield were less than 0.9.As a consequence,conventional WBM can cause heavily formation damage.OBM was limited due to the higher costs and serious pollution of the environment.The low density and micro foam control fluid was optimized to overcome this challenge.It had such benefits as low density,high strength foam,favorable stability and strong carrying capacity.Field practices indicated the fluid presents stable more than 48 h and it had a adjustable density range of 0.7-0.99 g/cm~3.It had a oil resistance of more than 8% and a temperature resistance of more than 100 ℃.The return permeability could be more than 80%.It has a convenient operation and lower costs and can control formation damage effectively.The skin factor of the wells drilled with the micro foam fluid falled in 0.20-2.34.更多还原