塔河油田风化壳卡取难点及方法应用

Difficulty in Determination of Weathering Crust and Application of Determining Method in Tahe Oilfield

塔河油田奥陶系风化壳中完卡取过程中,若风化壳以上地层预留过多,对目的层钻进和后期采油造成不利影响;若揭开目的层过多,可能导致井漏、井壁垮塌恶性事故,污染油气层等问题。通过塔河区块近4年奥陶系风化壳卡层情况的统计,对风化壳卡取类型、特征及卡取难点进行梳理、分析,总结归纳塔河油田奥陶系风化壳中完卡取5种技术方法:科学预测精细对比、碳酸盐含量分析、控时钻进技术、元素录井技术及三维地质模型技术。通过对各项技术方法的现场应用与推广,4年内推进奥陶系风化壳中完卡取符合率上升5.25%,2016年符合率98.55%,创下了工区内新高,达到技术服务现场、全面提升地层卡层优良率及录井现场施工便利化、精准量化的目的。

In the process of determining the location of Ordovician weathering crust in Tahe Oilfield, too much reservation of the for-marion above the weathering crust is not favorable to the drilling of target stratum and the later oil production, but too much uncover-ing of target stratum may lead to the malignant accidents such as well leakage, borehole collapse and oil/gas reservoir pollution. Basedon the statistics of the Ordovician weathering crust determination events in Tahe block in recent 4 years, and the analysis of the types,characteristics and difficulties of weathering crust determining, 5 technical methods for Tahe oilfield Ordovician weathering crust de-termining are summaried scientific prediction and fine correlation, carbonate content analysis, timing drilling technology, elementlogging and 3D geological modeling. The application of these techniques makes the coincidence rate in the Ordovician weatheringcrust determination increased by 5.25% in 4 years, and the coincidence rate in 2016 was about 98.55%, which is the highest coinci-dence rate in the study area.