渭北油田岩石性能参数下PDC钻井破岩研究

Research on rock breaking simulation of PDC bit under rock property parameters in Weibei Oilfield

PDC钻头几何结构复杂性、岩石材料差异性以及钻井工况的系统性,使得钻头切削破碎岩石的机理研究与钻头对地层的匹配适应性一直存在很大困难。基于渭北油田取心所测得岩石力学参数,获得了该区块的H-J-C岩石响应模型参数,通过三维CAD软件和有限元软件建立PDC钻头破岩的三维非线性动态仿真模型,开展PDC钻头在该区块的破岩规律研究,并深入研究钻头破岩过程中的响应规律。结果表明,该区块下钻头垂向加速度为0. 1 m/s^2,钻头垂向速度稳定在0. 006 m/s,破岩功呈周期性变化、总体上升的规律趋势。该计算方法针对性较强,计算灵活便捷,为后期钻头—地层的适配性研究提供了技术手段。

The complexity of PDC bit geometries, the difference of rock materials and the systematicness of drilling conditions have caused great difficulties in the research of the mechanism of bit cutting or breaking rocks and bit＇s matching adaptability to the formation. Based on the rock mechanics parameters measured by coring in Weibei Oilfield,the parameters of the H-J-C rock response model of the block were obtained. Through 3 D mapping software and finite element software, a 3 D nonlinear dynamic simulation model of PDC bit breaking rock was established to study the rock breaking regularity of PDC bit in this block and to further study the response law of bit breaking rock. The results showed that the vertical acceleration of the bit was 0. 1 m/s2 , and the vertical speed of the drill bit was stable at 0. 006 m/s. The calculation method was more pertinent and flexible and convenient to calculate. It provided a technical means for the research of bit formation suitability in the later period.