水平井涡流排水采气技术优化

Optimization of Eddy Drainage Gas Production Technology in Horizontal Wells

针对边底水气藏水平井生产过程中的井筒积液问题,进行了涡流排水采气工艺的分析论证及优化研究。通过在井下生产管柱中下入涡流工具,改变气液两相流的流动形态,有效提高气井携液能力,从而避免气井井底积液,延长气井带水生产周期。研究表明,水平井井筒积液时,该井直井段底部至井口部分没有流体流动,这是由于斜井段气体从液体中滑脱后积聚在管柱顶部,而液体沉积在斜井段管柱底部,这样就在斜井段某区域形成了段塞流,阻碍了油气产出;使用涡流工具循环时,改变了两相流流态,段塞流持续时间很短,这说明通过涡流工具可以极低的压差移除管内积聚流体。现场应用表明,在合理选井的基础上,该工具具有良好的应用效果。

Aiming at the problem of wellbore fluid accumulation during the production of horizontal wells in edge and bottom water gas reservoirs, the demonstration and optimization of gas production technology by eddy drainage are carried out. To put eddy tool into downhole production pipe string changes the flow pattern of gas-liquid two-phase flow in wellbore, effectively improve the liquid carrying capacity of gas,thus avoiding bottom-hole fluid accumulation and prolonging the production cycle of gas wells with water. The research results show that there is no fluid flow from the vertical section bottom to the wellhead of a horizontal well when there is liquid accumulation in the wellbore of horizontal well. This is because in the inclined section, the gas slips away from the liquid and accumulates at the top of the pipe string, while the liquid deposits at the bottom of the pipe string, which leads to slug flow in a certain party of the inclined section and hinders the production of oil and gas. The flow pattern of gas-liquid two-phase flow was changed by using eddy tool, and the slug flow duration was very short, and the accumulated fluid in the pipe string could be removed with very low pressure difference. Field application shows that the tool has good applicationeffect on the basis of reasonable well selection.