改善低孔低渗油藏注水技术研究及应用

本布图油田投入开发的焉2区块,含油层位为侏罗系三工河组,属低孔低渗储层。这类油藏普遍存在注不进,采不出的矛盾。针对该区块注水井的欠注问题,在开展了储层特征及其对注水井吸水能力影响的研究基础上,通过该区吸水能力研究,确定了合理注水压力;通过研究井网、井距对注水开发的适应性,不断完善注采井网,西北部注水井已基本达到配注要求,满足注采平衡;通过开展室内实验研究,优化出适应储层的酸化配方、施工参数设计,矿场应用起到了显著的降压增注效果;制定了适合该区注入水水质标准并配套实施了水质处理技术,针对注水系统未建洗井回水管汇,引进应用了ZXJC30-Ⅳ型注水井活动洗井车洗井技术,有效地解决了注水井洗井问题和其它相关工艺配套技术应用问题。通过对研究成果的现场应用,使本布图油田焉2区块实现了良性注水开发,同时对于开发类似区块提供了可借鉴的经验。

Research on improvement of water-injection technology in low porosity and low permeability reservoir and its application

The oil-bearing formation of Yan 2 block of Benbutu oil field is Jurassic Sangong River group,which is low porosity and low permeability.Those reservoirs generally confronted with water-injection and oil production difficulties.Based on formation characterization and researches of its influence on water absorbing capacity of injection wells,the reasonable injection pressure was determined by water absorbing capacity research of this block.The injection allocation requirement and injection and production balance was maintained in the northwest injection wells by research on the adaptability of water-injection under the influence of well pattern,well spacing and the improvements of injection pattern.The acidizing treatment and the parametric design was optimized by conducting the in-house experiments,and its field applications have obvious depressurization and injection augment effects.The standard of water quality for oilfield injection was established and water quality treatment technology was proved suitable to this block. ZXJC30-IV well washing truck was applied for water-injection systems with no returning pipelines,and well washing problems in injection wells and its applications for other matching technologies were also effectively solved.By application of the researching results of this paper,Yan 2 block of Benbutu oil field implemented the favorable water-injection production and provided valuable experiences to other similar blocks and oil fields.