用于低压低渗透油气藏的可循环泡沫防塌钻井液

A Recyclable Foaming Drilling Fluid Suitable for Drilling Low Pressure Low Permeability Reservoirs.

分析了低压低渗透油气藏储层损害与保护的特殊性及泡沫钻井液的防塌机理，优选出了适用于该类油气藏的强抑制性可循环泡沫防塌钻井完井液，并对该体系进行了性能评价和现场施工工艺探索。性能评价实验结果表明，该钻井完井液具有较低的密度在0．60-0．95g／cm63之间可调，能满足低压地层钻井的需要；具有较强的抑制性，与油基钻井液接近，能有效地预防钻井液对低压低渗透储层的损害；流变性和滤失性好、抗原油污染和抗温稳定性强（120℃），能适应井深3000m以内的直井、斜井和水平井钻井施工需要。

A recyclable inhibitive foaming drilling fluid suitable for drilling low pressure low permeability reservoirs was formulated based on the analysis of permeability impairment and protection of the low pressure low permeability reservoirs,and mechanism of bore hole sloughing prevention using foaming drilling fluids.Laboratory study of this foaming drilling fluid showed that this fluid had a lower density(adjustable between 0.6 and 0.95 g/cm3) and a good inhibitive performance.Rheology control,filtration and contamination control,and high temperature stability all were satisfactory,suitable for use in vertical,deviated and horizontal wells with depth in less than 3,000 m.