延长油田聚合物驱油分层注入新技术

New Technology of Stratified Injection for Polymer Flooding in Yanchang Oilfield

延长油田是国内最早开发聚丙烯酰胺驱油技术的油田之一。1吨聚合物可增产100~120吨,采收率由40%以上提高到目前的50%。针对该油田的地质和物化特征,开发了聚合物驱油机理、产能预测、方案优选、国产优质聚合物生产、地面注入、井下分层注入、注时分层测试等一系列技术。该油田为非均质多层砂岩油藏,在聚合物驱过程中,还需要采用分层注入技术来缓解层间差异,提高采收率,提高整体开发效果。该论文简要介绍了分层注聚技术的发展与实践,重点介绍了偏心异分子量注聚技术的原理、管柱结构、参数,以及在延长油田的现场应用情况。

Yanchang Oilfield is one of the earliest which develop displacement technology by poly acrylamide(PAM).1 ton polymer can increase 100 to 120 tons of oil,the recovery from above 40%to nowadays 50%.In view of the geological and physicochemical characteristics,a series of technologies have been developed,such as polymer flooding mechanism,the productivity forecasting,proposal optimization,domestic excellent quality polymer production,surface injection,downhole separate layer injection,and separate layer testing during injection,etc..The oilfield is characterized by heterogeneous multilayer sandstone reservoir,during polymer flooding,separate layer injection technology is also needed to alleviate the interlayer differences,enhance oil recovery and improve the whole development effect.This paper briefly introduces the development and practice of separate layer polymer injection technology,presents its focus on the principle,string structure and parameters of eccentric different molecular weights polymer injection technology and its field applications in Yan chang oilfield.