特高含水油藏开发后期深部调驱+二氧化碳吞吐技术

In-Depth Profile Control and Carbon Dioxide Huff-Puff in the Late Stage of Ultra-High Water-Cut Oil Reservoir Development

针对中高渗砂岩油藏进入特高含水开发后期,油藏优势渗流通道极其发育,常规控水稳油对策无法抑制含水持续升高的问题,利用深部调驱封堵优势渗流通道,改变液流方向,挖潜水淹路径绕流区剩余油,同时,利用CO_2吞吐降低原油流动性,提高井间驱油效率。研究结果表明:利用深部调驱+CO_2吞吐技术,可实现井间压力平衡,扩大驱替波及体积,达到降水增油的目的。该项技术在南堡凹陷Ng_1~2油藏实施1 a后,累计增油1.82×10~4t,含水降低12.4个百分点,采收率提高1.6个百分点。研究成果对特高含水油藏进一步提高采收率具有重要意义。

Due to the well-developed predominant flow channels in the late stage of medium-high permeability sandstone oil reservoir with ultra-high water-cut, conventional measures for water-cut control and production stabi- lization are limited in control the water-cut increase. In-depth profile control is used to plug the predominant flow channels, change flow direction and recover the remaining oil around the flooding channels. In addition, carbo diox- ide huff-puff is implemented to reduce oil mobility and enhance inter-well displacement efficiency. Research indi- cates that the in-depth profile control and carbon dioxide huff-puff could reduce water-cut and stabilize oil produc- tion by realizing inter-well pressure balance and enhancing swept volume. After implementation in Ng12 oil reservoir of Nanpu Sag for one year, the cumulative oil increment is 1.82×104t, the water-cut is reduced by 12. 4 persent- age points and the oil recovery factor is enhanced by 1.6 persentage poiuts. This research could provide certain sig- nificance for further enehancing oil recovery in ultra-high water-cut oil reservoir.