低密度全油基钻井液在塔中低压油气藏的应用研究

发布时间：2018-11-25 16:59

【摘要】：基于塔中11井区志留系砂岩易水锁伤害、地层压力系数低等钻井储层保护的难点,通过国内外低压油气藏保护的钻井液体系调研,认识到使用低密度全油基钻井液是一种比较经济可行的保护措施。通过低密度全油基钻井液的单剂合成和筛选,完成了低密度全油基钻井液的体系构建。构建了以柴油为基液的低密度全油基钻井液。实现了低密度全油基钻井液的密度低至0.90g/cm3,抗温能力达120℃～150℃,抗钻屑和水污染10%～20%,滚动回收率达到95%以上,岩心渗透率恢复值达90%以上的良好效果。研制的低密度油基钻井液在塔中11井区1口直井和1口水平井井应用,实现了微欠平衡或平衡钻井,减少了压持效应和井底压差,提高了机械钻速,同时减少了钻井液中的固相向地层的侵入量；缩短了钻井液浸泡时间,在高温高压下滤失量低,减小了钻井液污染半径；从本质上降低了水锁伤害。低密度全油基钻井液在塔中应用情况表明,低密度全油基钻井液具有性能稳定、维护简单、机械钻速快等特点,各项性能满足了钻井液设计性能和储层保护功能。通过油基钻井液回收和重复利用,节约了钻井成本,也减少了环境污染。低密度全油基钻井液的储层保护效果在于完井测试表皮系数0；岩心静态渗透率恢复值90%,动态渗透率恢复值75%；其120-C失水8m1,两口井完井试油产量都超过相应邻井产量。
[Abstract]:Based on the difficulties of reservoir protection for Silurian sandstone in Tazhong 11 well area, such as easy water lock damage and low formation pressure coefficient, the drilling fluid system of low pressure reservoir protection at home and abroad is investigated. It is recognized that the use of low density oil-based drilling fluid is an economical and feasible protection measure. The system of low density whole oil based drilling fluid was constructed by single agent synthesis and screening of low density oil based drilling fluid. A low density oil-based drilling fluid based on diesel oil was constructed. The low density oil based drilling fluid has a low density of 0.90 g / cm ~ 3, a temperature resistance of 120 鈩，

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