Abstract The Iceland Deep Drilling Project (IDDP) well IDDP-1 in the Krafla geothermal field in Iceland is the most powerful geothermal well on record, with a maximum wellhead temperature of 452 °C and 140 bar pressures. In the end, the well had to be abandoned and closed permanently due to several casing failures, including a number of collapses and tensile coupling failures of the innermost casing – the production casing. The history of this first IDDP well is discussed in this paper, revealing the conditions the carbon steel was exposed to. The metal samples degrading mechanism was investigated by mechanical testing and microstructure analysis. For the first time, material used in geothermal steam in situ above 400 °C for a long period was investigated and a new alarming cracking mechanism detected. This cracking mechanism due to formation of methane inside the carbon steel structure results in severe cracks and as a result the steel loses its strength and ductility. This study reveals the need for review of material selection for high-temperature geothermal wells.

中文翻译：

---

高温IDDP-1井口材料研究

摘要 冰岛克拉夫拉地热田的冰岛深钻项目（IDDP）IDDP-1井是有记录以来最强大的地热井，最高井口温度为452°C，压力为140 bar。最后，由于多次套管故障，包括最内层套管（生产套管）的多次坍塌和拉伸耦合故障，该井不得不放弃并永久关闭。本文讨论了第一口 IDDP 井的历史，揭示了碳钢所处的环境。通过力学测试和显微组织分析研究了金属样品的降解机理。首次对400°C以上地热蒸汽原位长期使用的材料进行了研究，并发现了一种新的令人震惊的裂解机制。由于在碳钢结构内部形成甲烷，这种开裂机制会导致严重的裂纹，从而使钢失去强度和延展性。这项研究揭示了对高温地热井材料选择进行审查的必要性。