水平井地质导向方法

Discussion on geosteering methods of horizontal wells

为了更好地开采油藏剩余油,提高采收率,降低综合成本,提高单井产量,近3年来水平井技术在冀东油田得到快速应用和发展,成为夺油上产的主要手段之一。地质导向是指导现场定向施工,及时引导钻头走向,最大限度地钻遇油层的技术,直接影响水平井成功实施。从实践出发,针对LWD测量仪器滞后于钻头的实际,利用深、浅电阻率探测深度的差异,总结出LWD曲线分析法;利用邻井资料分析,形成了6种关于钻头相对油层位置的判断方法,并对在钻出油层后如何计算实际地层倾角,指导钻头重入油层做出了比较深入的分析,提出4种地层状态下计算实际地层视倾角的公式。这些方法在水平井钻探中得到了广泛应用,使水平段油层平均钻遇率达到80%以上,取得了良好的开发效果。地质导向技术已经成为打好水平井的关键技术。

For better exploitation of residual reservoirs, improvement of recovery, reduction of comprehensive cost and increment of single well production, technology of horizontal well in Jidong Oilfield, applied and developed rapidly in recent three years, becomes one of the main means to increase oil yield. Geosteering, a technology for guiding field directional construction and trend and maximized reservoir drilling of bit, has direct influence on successful operation of horizontal well. From actual conditions, against fact of measurement instrument of LWD (Logging While Drilling) lagging bit, this paper concludes LWD curve analysis by different detecting depth of deep and shallow electrical log, forms six judging methods of bit position relative to reservoirs by analysis on adjacent angle datas, and puts forward formulas of calculating apparent dip of actual formation in four out layer state by deeper analysis of how to calculate dip angle of actual formation and guiding bit reentry in reservoir. These methods, applied widely in horizontal well drilling and making average drilling ratio in horizontal section reservoirs over 80% , obtain good development effect. In a word, geosteering has been key technology in horizontal well drilling.