Abstract Joined the 1 GW installed capacity club in 2017, Turkey has undeniable production and potential for geothermal energy, ranking top 5 worldwide. Harnessing geothermal energy has many challenges, from planning to commercial phases. This study features the challenges, experiences and latest advances in drilling fluids utilized in geothermal well construction process in Turkey; focusing to provide a comprehensive information about drilling fluids systems and their design principles in geothermal wells in Turkey. GEOS act as a major player in Turkish geothermal drilling industry; providing drilling and completion fluids, solids control equipment and waste management services; having drilled more than 250 deep geothermal wells in utmost challenging downhole environments of Turkish geothermal fields with major operators. Drilling geothermal wells comes along with several challenges. Most important of which could be high temperatures, relatively high pressures and some of the wells having tough lithologies to drill through. Providing wellbore stability across dispersive shales or pressurized ophiolitic formation requires special attention in planning and execution phases. Another special attention has been given to minimize formation damage in reservoir intervals of geothermal wells. Therefore, different options of reservoir drilling fluids are presented and discussed in detail. Drilling fluids systems used in geothermal wells have evolved over the last decade and tailored to suit the challenges to be faced, not only in top hole and intermediate intervals, but also in reservoir intervals. Main objective of this paper is to share the knowledge and experience gained during the learning curve over the years; extensive laboratory studies and field case studies for geothermal well drilling fluids in Turkey are presented.

中文翻译：

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土耳其地热井钻井液系统概述及设计原则

摘要 土耳其于2017年加入1GW装机俱乐部，地热能产量和潜力不可否认，位居全球前5位。利用地热能面临许多挑战，从规划到商业阶段。本研究重点介绍了土耳其地热井施工过程中使用的钻井液所面临的挑战、经验和最新进展；专注于提供有关土耳其地热井钻井液系统及其设计原则的综合信息。GEOS 是土耳其地热钻井行业的主要参与者；提供钻井和完井液、固体控制设备和废物管理服务；与主要运营商在土耳其地热田最具挑战性的井下环境中钻探了 250 多口深地热井。钻井地热井伴随着几个挑战。其中最重要的可能是高温、相对较高的压力以及一些岩性难以钻探的井。在分散的页岩或加压蛇绿岩地层中提供井筒稳定性需要在规划和执行阶段特别注意。另一个特别注意是尽量减少地热井储层层段的地层损害。因此，提出并详细讨论了油藏钻井液的不同选择。地热井中使用的钻井液系统在过去十年中得到了发展，并针对所面临的挑战进行了定制，不仅在顶孔和中间层段，而且在储层层段。本文的主要目的是分享多年来在学习曲线中获得的知识和经验；介绍了土耳其地热钻井液的广泛实验室研究和现场案例研究。