深井高速涡轮钻配套同径取心技术研究

Research on the same diameter coring drilling technology used by high-speed turbodrill for deep well

摘要:

分析了涡轮钻具结构特征及性能特点，在深井、特深井的高温高压、强研磨性地层中，涡轮钻具基本上成为唯一可选的用于复合钻进提速降本的井下动力钻具。针对深部资源的勘探开发需求，阐述了现有涡轮钻具同径取心技术的优势及存在的问题，利用数值模拟仿真技术分析和研究了涡轮钻具同径取心过程中钻井液的流动状态对取心效果的影响，认识到涡轮钻具可耐高温，适于深井、特深井全面钻进及取心钻进，但其高转速在取心钻进过程也容易造成岩心磨损、岩柱螺旋，而改善同径取心钻具高速单动性能、加长涡轮钻具螺旋稳定器、利用反螺旋扰流板等技术措施，有利于减小取心钻具井底的涡动、降低岩心内外管轴向速度差，从而提高涡轮钻同径取心钻进的岩心质量。

Abstract:

The structural and performance characteristics of turbodrill are analyzed. In the high-temperature and high-pressure and highly abrasive strata of deep and extra-deep wells， turbodrill has basically become the only alternative downhole dynamic drilling tool to increase speed and reduce costs in composite drilling. In view of the exploration and development requirements of deep resources， the advantages and existing problems of the existing turbodrill core-extraction technology are described. In addition， numerical simulation technology is used to analyze and study the influence of drilling fluid flow state on the coring effect in the process of simultaneous coring with turbodrill. It is recognized that turbodrill can withstand high temperature and is suitable for full drilling and coring in deep and extra-deep wells， but its high rotational speed is also easy to cause core wear and rock column spiral in the process of coring drilling. Improving the high-speed single motion performance of the core-drilling tool， lengthening the spiral stabilizer of the turbodrill and using the reverse spiral spoiler are beneficial to reduce the vortex motion at the bottom of the hole and the axial velocity difference between the inner and outer tubes of the core， so as to improve the core quality of the core-drilling tool.