肯吉亚克油田非盐丘井PDC钻头设计及实验研究

Design of PDC bit and its laboratory test for non saline dome wells in Kenkiyak Oilfield

为提高肯吉亚克油田非盐丘井钻井速度,根据地层岩石力学参数评价结果,利用有限元方法对影响PDC钻头攻击性和抗冲击性的齿前角、冠部形状等结构参数与破岩效果之间的关系进行了研究,并对PDC钻头的结构进行了优化设计。根据设计结果试制了直径为120.65mm、齿前角分别为-15°、0°、和5°的3只PDC钻头,并在室内同一岩样上进行实钻模拟实验。结果表明,在其他参数相同的条件下,齿前角为5°时钻头的平均机械钻速比齿前角为-15°时提高42%,说明增加PDC钻头齿前角是提高钻头攻击性的有效方法,这与数值模拟结果是一致的。研究结果为该地区全尺寸钻头的制造提供了理论依据。

In order to raise drilling speed of the non saline dome wells in Kenkiyak Oilfield, the relationship between rake angles of the cutter, profile of the bit, which have effect on cutting depth and impact-resistant of PDC bit cutters, and cutting efficiency is studied respectively using finite element analysis according to rock properties of the research area. The structure of the PDC bit is then optimized by using the research result. Three 120.65mm PDC bit samples whose cutter rake angles are -15°, 0° and 5°respectively are built on the basis of optimization result of the PDC bit structure and are used to drill the same rock sample in the laboratory. The test result shows that rate of penetration （ROP） of the PDC bit whose cutter rake angle is 5° is 42% higher than that of the bit whose cutter rake angle is -15°, which shows that the cutting depth of the PDC bit increases when its cutter rake angles are raised as other parameters kept in constant. The test result is in accordance with the result of numerical simulation. The research provides theoretical foundation for the full scale bit manufacture in the following stage.