非渗透钻井液体系在梨树断陷的研究与应用

Study and Application of Impermeable Drilling Fluid System in Lishu Fault Depression

梨树断陷碎屑岩储层多为低孔低渗致密碎屑岩储层,存在井壁稳定性差和储层保护难度大的钻井技术难点。为增强井壁稳定性和储层保护效果,开展了非渗透钻井液的研究与应用工作。根据钻井液抗温性、抑制性、储层伤害等室内试验评价结果,表明非渗透钻井液抗温稳定性好,防塌能力强,返排压力低,能够有效封堵地层孔隙,渗透率恢复率达到80%以上,表皮因数较低,具有储层保护的效果。

Clastic reservoir in Lishu Fault Depression was a low porosity and low permeability tight sandstone reservoir,there existed technical problems of poor borehole stability and difficulty for formation protection. To improve the borehole stability and formation protection,an impermeable drilling fluid system was studied and used. The experimental results of temperature resistance,inhibition and formation protection indicate that the impermeable drilling fluid system has good temperature resistance and stability,strong anti-sloughing capacity and low backflow pressure,it can be used to seal pores in formation with permeability recovery value over 80% and low skin factor,and good effect is obtained for formation protection.