孤东油田挖潜剩余油实用技术应用效果评价

Effect of practical techniques in producing remaining oil in Gudong Oilfield

近几年,孤东油田在剩余油描述与挖潜方面取得了新进展,利用老区新井、碳氧比测井、精细油藏描述等技术预测剩余油分布区,采用在老区打水平井、聚合物/石油磺酸盐二元复合驱先导试验等实用技术挖潜剩余油。截至2007年12月,孤东油田已钻水平井43口,累计增油42×104t。新井钻遇有效厚度核算、产能到位率评估、实际钻遇情况与设计指标对比、新井产量与同层老井产量对比认为,老区新井改善了资源利用程度、提高了产能和采收率。孤东油田自2003年9月开展国内首例聚合物/石油磺酸盐二元复合驱先导试验,截至2007年12月,累计增油13.1×104t,翁氏模型预测和修匀-递减法标定二元复合驱可提高采收率7.6%。扣除无效采液后的可采储量预测、消除开发时间差异后的产量指标评价、应用可采储量采油速度划分油田开发阶段等评价方法深化了对开发规律的认识。

In recent years, the Gudong Oilfield has made a great progress in the description and production of remaining oil. By drilling new wells in old districts, carbon-oxygen log, fine reservoir description, etc. , the remaining-oil distributed zones were predicted, and by drilling horizontal wells in old districts, surfactant-polymer-combination flooding pilot etc. , the remaining oil was produced. By Dec. 2007, it had drilled 43 horizontal wells, and the cumulative oil increment amounted to 42 × 10^4 t. According to the statistics of the drilled effective thickness of new wells, the evaluation of the obtainable productivity, the comparison between the actual drilled effective thickness and the estimated, and the production comparison between new wells and the old wells, the method of drilling new wells in old districts improved the resources utilization degree, oil productivity and recovery. The first-ever S-P composite flooding pilot was carried out in Sep. 2003 in the Gudong Oilfield. By Dec. 2007, the cumulative oil increment was 13.1 × 10^4 t. The evaluation results of the Weng-model and the graduation-decline method indicated that the S-P pilot increased the oil recovery factor by 7. 6%. Predicting recoverable reserves after deducting ineffective liquid production, evaluating production index after eliminating production time difference, dividing the oilfield development phase using the production rate of recoverable reserves and other evaluation methods are helpful to the understanding of the oilfield development rule.