浅层超稠油双水平井SAGD立体井网开发模式研究

Study on SAGD Stereo Well Pattern Development Mode of Dual Horizontal Wells for Shallow Extra Heavy Oil

针对连续油层厚度大、夹层较发育的SAGD开发油藏,提出一种双层SAGD井网、立体交错部署的开发模式,通过数值模拟研究进行验证,并对生产操作参数进行优化。研究结果表明:采用双层SAGD立体井网可有效提高储量利用率和采油速度,减轻夹层对生产带来的不利影响;双层SAGD蒸汽腔呈现出"孤立发育—上升扩展—相互接触—聚并融合"的发育模式,同时具有汽驱辅助和重力泄油双重开采机理;生产后期,蒸汽腔聚并融合后,上部井组继续注汽,更有利于提高开发效果。双层SAGD立体井网已在风城油田Z区块投入现场应用,取得初步效果。该研究对于类似油藏SAGD高效开发具有借鉴和指导意义。

In allusion to the SAGD development reservoir with large continuous oil layer thickness and relatively developed interbed,this paper presented a development mode of double- layer SAGD well pattern and stereo crisscross deployment,which was verified by numerical simulation study,and production operation parameters were optimized. The study results showed that the double- layer SAGD stereo well pattern could effectively improve the reserve utilization ratio and oil recovery rate,and reduced the adverse effect of interbed on the production; the double- layer SAGD steam chamber exhibited an ' independently developed,ascended and extended,mutually contacted,coalesced and merged ' development pattern,and simultaneously,it had the steam flood auxiliary drainage and gravity drainage dual withdrawal mechanism; at production tail,after the steam chamber had been coalesced and merged,steam injection continued in the upper well group,and this was more favorable for the improving of the the development effect.The double- layer SAGD stereo well pattern has been applied actually in Z block of the Fengcheng oilfield,and preliminary effect has been achieved. This study has reference and guidance significances to the SAGD efficient development of similar oil reservoirs.