气举反循环连续取心工艺探索

气举反循环钻进技术是钻井工程中一种比较成熟的钻进手段,已经得到了广泛应用。但气举反循环连续取心技术仍处在探索研究阶段,前人已经针对这一技术做了原理性探究试验,但尚未进行连续的取心试验,而且现有的双壁钻具也存在无法满足由于上返岩心质量和直径大对其密封性和耐用性的要求。因此有必要进一步开展理论研究、优化钻具设计、进行连续取心试验来探究这一工艺发展前景。通过试验证明大通径双壁钻具设计可靠耐用,成功连续取得岩心。所取岩心及时,无污染,代表性强,能较真实的反映地层层位、深度、颗粒级配,不存在对岩心反复冲刷及重复破碎状况。

Air lift reverse circulation continuous coring technology

Gas lift reverse circulation drilling technology is a relatively mature drilling method in drilling engineering and has been widely used. However, the gas-lift reverse circulation continuous coring technology is still in the stage of exploratory research. The predecessors have done theoretical exploration tests on this technology, but continuous coring tests have not been carried out, and the existing double-wall drilling tools are also unable to Meet the requirements for sealing and durability due to the quality and diameter of the top-return core. Therefore, it is necessary to further carry out theoretical research, optimize the design of drilling tools, and conduct continuous coring tests to explore the development prospects of this technology. Tests have proved that the design of the large diameter double-wall drilling tool is reliable and durable, and the core has been successfully obtained continuously. The cores taken are timely, non-polluting, and representative, and can truly reflect the stratum level, depth, and particle gradation. There is no repeated erosion and repeated fragmentation of the core.