稠油水平井多点注汽技术

Multipoint Steam Injection Technology in Horizontal Well for Heavy Oil

欢喜岭采油厂稠油水平井采用常规笼统注汽方式开发,存在水平段动用不均的问题。对常规注汽出汽位置、油层非均质性、蒸汽超覆、汽窜等影响稠油水平井水平段动用不均的因素进行了分析。提出了利用多点注汽设计软件进行计算和模拟井下温场分布,采取蒸汽伞和配汽阀进行分单元多点注汽的多点注汽技术。介绍了多点注汽技术中管柱结构、配汽阀、蒸汽伞、多点注汽设计软件等关键技术的结构及功能。欢喜岭采油厂现场应用结果表明,多点注汽技术实施后,平均单井增油300t以上,最高单井增产达500t以上,该技术能够改善水平段吸汽剖面,有效改善水平井段动用程度,从而达到提高周期产油量的目的。欢喜岭采油厂欢127-H3井应用多点注汽技术,沿整个水平段设计4个注汽阀,措施后排水期由原来的12d缩短为2d,周期产油由761.3t提高到1282.1t。

Horizontal sections can＇t be produced totally in the way of commingled steam injection in the horizontal wells for heavy oil of Huanxiling oilfield.The influencing factors of it are analyzed including conventional steam in-off position,reservoir heterogeneity,steam overlapping and gas channeling.Multipoint steam injection technology is put forward.Its corresponding software may be applied for calculating and simulating temperature distribution of downhole.Steam umbrella and steam distributing valve may be applied for multipoint steam injecting by sub-unit.The structure and function of the key technology on string,distributing valve,steam umbrella and the software are introduced.The application in Huanxiling oilfield shows that incremental oil for single well is more than 300t at the average and more than 500t at the most after the technology is implemented.It can improve the steam injection profile and produced degree at the horizontal sections,with the result of increasing periodic oil production rate.Four steam injection valves are designed along the whole horizontal sections in well Huan127-H3 of Huanxiling oilfield.After the technology is applied in this well,drainage period is shortened from 12d before to 2d now and periodic oil production rate enhanced from 761.3t to 1282.1t.