缝洞型油藏溶洞内底水锥进现象的可视化研究

设计与建立了研究大尺度溶洞内近井地带油水两相流动特性的可视化实验系统,通过摄像机记录了水锥从形成到突破油层的过程,研究了水锥产生的机理和演变特性,同时得到了水锥高度与油层厚度随流量的变化关系。实验结果表明:水锥形成初期,油水界面存在轻微波动;水锥变化过程中,出现锥顶凹陷;底水突破油层时,锥顶处油水存在轻微混合;水锥高度与油层厚度变化率随流量的增大而增加。

Visualization Study on the Bottom-Water Coning in Large-Scale Cavity of Fracture-Cavernous Reservoirs

Experimental system of oil-water two-phase flow in near-well of large-scale cavity was designed and set up in this paper.The evolution process of water-coning which used to study the formation mechanism of water-coning was recorded by a camera.Water-coning heights and oil-layer thicknesses were measured,and their relationships with flow rates could be obtained.Results showthat oil-water interface fluctuates slightly in the early stage of water-coning and sunken cone may appear in the formation of water-coning.When bottom-water breakthrough appears,oil may mix with water at the top of water-coning.Water-coning height and the change rate of oil-layer thickness increase with the increase of flow rate.