摘要
针对渤海油田浅部储层井眼蠕变缩径和井壁坍塌等问题,利用室内试验研究了浅部砂泥岩岩石物性与力学性质,测量了砂泥岩在不同含水量和不同偏应力下的蠕变速率,并根据Weertman模型进行了蠕变参数拟合。在室内试验基础上,利用有限元模型对井眼缩径的时变规律进行了研究。以曹妃甸6-2油田A井为例进行了现场应用分析。研究结果表明,在偏应力较大时地层会进入加速蠕变阶段,由于蠕变速率过快导致地层产生蠕变缩径坍塌。根据研究结果给出了抑制蠕变、延长钻井周期等相关的钻井工程技术对策,研究结果可为现场选择安全合理的钻井液密度提供指导。
To address the problems of wellbore creep and shrinkage and wellface collapse in shallow reservoirs of Bohai Oilfield, the physical properties and mechanical properties of shallow sandstone and mudstone are studied by laboratory experiments, and the creep rate under different water content and different deviator stress was measured, thereby the creep parameter fitting is conducted according to the Weertman model. Based on the laboratory experiment, the finite element model is used to study the time-varying law of the borehole shrinkage. The field application analysis is carried out in the Well A of Caofeidian 6-2 Oilfield. The results show that the formation will enter the accelerated creep stage at high deviator stress. Borehole shrinkage and wellface collapse will occur due to the excessive creep rate. According to the research results, related drilling engineering technical countermeasures for controlling creep and prolonging the drilling cycle are attained. The study results can provide guidance for selecting safe and proper drilling fluid density.
作者
李治衡
刘海龙
庹海洋
张磊
张羽臣
Li Zhiheng;Liu Hailong;Tuo Haiyang;Zhang Lei;Zhang Yuchen(CNOOC Tianjin Company;State Key Laboratory of Offshore Oil Exploitation)
出处
《石油机械》
北大核心
2019年第12期44-49,共6页
China Petroleum Machinery
关键词
浅层砂泥岩
蠕变缩径
井壁坍塌
安全钻井周期
shallow sandstone and mudstone
creep and shrinkage
wellface collapse
safe drilling cycle
