纳米气泡驱油技术的动态封堵机理与渗透率适配性研究OA

Conventional water flooding is a fundamental technology in oilfield development.However,in the late high water-cut stage,reservoir heterogeneity tends to induce the formation of preferential flow paths,leading to ineffective circulation of injected water and thereby constraining further improvement in oil recovery.To overcome this technical bottleneck,research on flow control based on the dynamic plugging mechanism of nanobubbles was conducted.Core flooding experiments demonstrate that nanobubble water exhibits a significant plugging capability in reservoirs with permeability ranging from 10.12×10-3 to 100.30×10-3 μm2,with a resistance factor of 1.33-1.51 and a residual resistance factor of 1.18-1.38.Furthermore,large-scale micromodel displacement experiments visually reveal the enhanced oil recovery(EOR)mechanism:Nanobubbles selectively plug high-permeability channels,effectively diverting flow to unswept zones,which increases the swept volume by 28.6％and enhances the recovery by 20 percentage points.Based on these findings,this study innovatively puts forward the"three-zone pore-throat adaptability concept,"identifying the optimal plugging efficiency within a bubble-to-pore-throat diameter ratio of 0.1-0.3.The engineering effectiveness of this technology was validated in a field trial in the W39 well group in Shengli Oilfield.Following the continuous injection of 10 800 m3 of nanobubble water(average diameter:550 nm;concentration:>4.0×108 bubbles/mL;preparation cost:0.5 RMB/m3),the injection pressure increases by 2.4 MPa,while the daily oil production of the mainline well rises by 17.6％,and its water cut decreases by 4.1 percentage points.