【作者】 何远信；

【导师】 夏柏如；

【作者基本信息】 中国地质大学（北京） ， 地质工程， 2006， 博士

【摘要】 环境科学钻探是取得古地理、古气候、古环境变迁及环境污染程度等实物资料的唯一技术手段。通过对样心进行物理、化学及生物分析,能够正确演绎古气候及环境变化的规律,为国家经济区域规划提供决策依据。 环境科学钻探孔深一般在500m以上,需要全孔取心。取出的岩心要求完整、未扰动、未受污染、代表性好,但目前的钻探技术仍无法满足要求。主要表现在取心技术和钻井液技术研究滞后,不适应环境科学钻探的技术要求。 本研究根据环境科学钻探的特点和存在的主要问题,重点开展取心技术和钻井液护壁护心技术研究,以解决环境科学钻探工程中取心率低、孔壁稳定性差这两大技术难题。科技部和国土资源部立项给予经费支持。 经过充分论证,提出了以射流式取心技术和环保型钻井液技术为主攻方向的技术思路。重点通过研制新型射流式取心钻具和环保型钻井液体系(EPM)来实现提高岩心采取率和孔壁稳定性的预期目标。 射流式取心钻具的研究内容包括射流元件的研究、抗涡动钻头的研究及隔水装置的研究。 环保型钻井液体系的研究内容包括环保型钻井液材料生物毒性检测方法及标准的研究,优质环保处理剂的研制或遴选以及环保型钻井液体系配方的试验研究。 现场示范应用表明:射流元件设计合理、结构紧凑、效果显著,对内管中岩心起到了“悬浮”保护作用;抗涡动钻头钻进中稳定性好,对岩心起到了稳定“树心”的预期功效;隔水装置实现了对冲冼液流量分配的控制,避免了冲洗液对岩心根部的冲蚀。环保型钻井液体系(EPM)组分简单,无毒性、现场配浆维护简便,降失水、防塌、润滑功能显著,能够有效封堵裂隙漏失。其触变性能优良,有助于维护岩心的完整。EPM体系完全满足了环境科学钻探工程对钻井液综合性能的要求。射流式耽心钻具和环保型钻井液体系(EPM)两大成果的联合作用,使取心率从原来常规技术的40%提高到90%以上,而且钻进中孔壁稳定、起下钻顺畅。 总之,开展环境科学钻探技术研究为当前环境科学钻探工程的实施提供了及时有力的技术支撑。射流式取心技术和环保型钻井液技术解决了环境科学钻探工程取心率低和护壁护心差两大技术难题,填补了国内空白,促进了环境科学钻探技术的进步。更多还原

【Abstract】 Environmental scientific drilling is the only technical method to obtain real information or sample in the reaserch on the change of palaeogeography, palaeometeorology and palaeoenvironment and the level of environmental contamination. Based on physical, chemical and biological analyses on the sample, the law of palaeometeorological change and enviommental change can be correctly deduced. Environmental scientific drilling will provide a basis for the decision of regional planning for national economy.Environmental scientific borehole is generally deeper than 5oo meters and full hole coring is needed. The core should be complete, undisturbed, uncontaminated and with good representivity. However, the conventional drilling techniques can not satisfy these requirements because of the stagnant research on coring and drilling fluid techniques.Based on the characteristics of environmental scientific drilling and in accordance with the main problems existed, this research project centres on the coring technique and the borehole wall and core protection technique by drilling fluid.This research project is financially aided by the Ministry of Science and Technology and the Ministry of Land and Resources.Based on a full argumentation, a technical line of taking fluidic type coring technique and environmental protective drilling fluid technique as the main research direction was put forward. That is, high core recovery and borehole wall stability would be mainly realized by new type fluidic coring tools and environmental protective drilling fluid system(Epm).The research on fluidic coring tools included fluidic elements, whirl-proof drill bits and water isolating device.The research on environmental protective drilling fluid system included the biotoxicity inspection method and standard of the environmental protective drilling fluid material, the development and selection of high grade environmental protective treatment materials and the research on the formular of the environmental protective drilling fluid system.Field demonstration application indicated that the fluidic elements were reasonably designed, with compact structure and remarkable results. The fluidic elements had a suspension effect on the core in inner tube. During drilling operations the whirl-proof drill bit realized very good stability, and thus stabilizing the core. Thecontrol of the distribution of drilling fluid flow rate was realized by the water isolating device, and thus the eorsion of drilling fluid to core root was avoided.The environmental protective drilling fluid system(Epm) is simple in component, non-toxic, easy in field preparation and maintenance, and is with remarkable functions of reducing filtrate loss, anti-collapse and lubrication. Thus fracture loss can be effectively sealed. Epm has good thixotropy, conducing to keeping the integrity of core. Field applications indicated that Epm completely satisfied the demands of environmental scientific drilling engineering on comprehensive properties of drilling fluid. The combination of fluidic coring tools and environmental protective drilling fluid system(Epm)increased the core recovery to more than 90 per cent from original 40 per cent by conventional technique, with the results of stable borehole wall during drilling process and smooth tripping.The research on environmental scientific drilling technique provides an effective and timely technical support for the implementation of environmental scientific drilling engineering. The fluidic coring technique and environmental protective drilling fluid technique solved the two main technical problems of low core recovery and poor core and borehole wall protection existed in environmental scientific drilling engineering, filling in the gaps in the country and promoting the progress of environmental scientific drilling techniques.更多还原