绒囊暂堵液原缝无损重复压裂技术

原缝无损压裂技术是指利用某种封堵材料,暂堵原裂缝,迫使压力向未压裂的地层发展,压裂完成后形成新裂缝且原裂缝的产液能力不受影响。绒囊工作液因其良好的暂堵性能而用于原缝无损压裂技术。室内评价表明,绒囊暂堵液能够增加人造岩心裂缝的流动阻力至25 MPa,封堵渗透率为17.5×10-3、163.9×10-3μm2的人造岩心后,地层原油渗透率0.7 h恢复90.9%和0.6 h恢复84.7%。LH1井现场先用绒囊暂堵液封堵地层,停泵压力稳定在22.0 MPa且10 min不降。重复压裂后60 d平均油井日产液量和日产油量比未压裂前30 d分别上升48.7%和119.2%,平均含水率下降了7.5%。表明绒囊暂堵液封堵性好,且对地层无伤害,可在提高单井产液量的同时降低含水率。

Study on Repeating Fracturing while Causing No Damage to Original Fractures

When a lost circulation material is used to temporarily plugging the a fracture, new fractures will be forced to propagate in non-fractured zones. This is the so-called "non-damaging to original fractures while fracturing" technology. In the application of this technology, the liquid conductance of the original fractures is not affected while new fractures are being generated. In laboratory studies, a temporarily plugging fluid containing chorionic vesicles increased the flow resistance of artificial core fractures to 25 MPa. When treated with this temporarily plugging fluid, artificial cores (permeabilities 17.5×10-3 μm2 and 164.9×10-3 μm2, respectively) had permeability recovery (to crude oil) of 90.9% in 0.7 hour and 84.7% in 0.6 hour, respectively. When using chorionic vesicle in the operation of the Well LH1, pump pressure was held up at 22.0 MPa for 10 minutes. The daily production rates of liquid and oil 60 days after re-fracturing were increased by 48.0% and 119.2%, respectively, compared with those 30 days before re-fracturing, and the average water cut was reduced by 7.5%. These facts showed the good performance of chorionic vesicle in temporarily plugging fluid in fracturing operation.