新的野猫开发商:追逐热能的地热开发商

美国正准备利用现有的石油和天然气技术迎来地热繁荣。该行业是否具备扩大规模所需的条件?

总部位于休斯顿的 Fervo Energy 在内华达州北部的 Project Red 增强型地热项目中创下了 2023 年创纪录的功率和流量,证实了其钻井技术的商业可行性。(来源:Fervo Energy

说美国的地热产业正在升温可能还只是轻描淡写。

地热公司领导人和其他能源行业人士曾一度因项目失败、规划不周和其他投资风险而被潜在投资者所排斥,但现在他们正在扭转这种局面。

他们正在使用石油和天然气公司剧本中的技术。想想水平钻井和多井平台。油田服务公司正在探索使用其产品的新方法,例如使用绝缘管来最大限度地减少热量损失并最大限度地利用地热井中的流体从地下移动到地面时的能量。

专家表示,尽管可能需要进行一些调整,但技术已经存在。

“人们普遍误以为,要将地热能推向市场,就必须进行所有这些创新。但……我们拥有所需的所有技术,” Fervo Energy战略副总裁 Sarah Jewett告诉 E&P。“我们拥有相当庞大且强大的客户群。因此,我们唯一要做的就是建设项目并推向市场。”

然而,实现商业规模的道路上仍然存在障碍。尽管前期成本正在下降,但仍然很高。资本限制和融资问题令人担忧。而且,地热也面临着整个能源行业面临的联邦许可和电网互联问题。

热储层

地热能利用钻入热储层的井来获取地下热量。传统地热不需要太多工程来获取热量,因为它更接近地表,有天然形成的裂缝和流体,例如在火山地区。

然而,下一代地热能源利用现有的石油和天然气技术来利用热量并从任何地方释放地热能源。借助增强型地热系统 (EGS),流体在一对由热储层中形成的裂缝连接的井中循环。闭环地热系统(也称为高级地热系统)通过地下的封闭井眼环路循环流体。提取的热量可用于通过直接使用热量为家庭和建筑物供暖或制冷,或利用温度更高的地热资源发电。

除了提供可再生能源之外,地热发电厂还提供基载电力,这意味着它们无论天气条件如何都能持续发电。可再生能源可用于将能源储存在地下,与太阳能和风能等可再生能源相比,所需的占地面积相对较小。

它有可能用可再生能源取代燃煤和燃气发电厂,或者至少减少其数量。

“下一代地热发电有望成为美国国内脱碳电力行业安全的关键贡献者。这是一个已准备好大规模发展的行业,”美国能源部 (DOE) 贷款计划办公室高级顾问、《商业化起飞之路:下一代地热发电》报告的主要合著者查尔斯·格特勒 (Charles Gertler) 表示。

“有一系列新兴技术刚刚问世,极大地扩展了可用于地热发电的总资源量,”他在今年早些时候讨论该报告的网络研讨会上表示。“整个行业具有非常显著和独特的起步优势。”

其中包括石油和天然气行业,该行业一直在向地热领域投入资金和技术知识。

油气效应

石油和地热钻探者有共同的负载。地热开发商和野猫钻探者一样,都在寻找热能。他们使用传感器和其他地质辅助工具进行现场评估并评估储层。井下工具、泵和涡轮机也是该过程的一部分,水力压裂工具和 EGS 注入泵也是如此。因此,看到石油和地热钻探者合作支持地热可能并不太令人惊讶。

服务公司贝克休斯从事地热业务已有约 40 年,提供的服务包括地热井建设、地下储层和可行性分析以及地热发电涡轮机技术。作为Wells2Watts 联盟的一部分,该公司目前的部分工作重点是闭环系统。 

贝克休斯与加州资源公司切萨皮克能源公司大陆资源公司和国际石油开发公司合作,希望改造已退役的油气井,并利用现有基础设施创建闭环地热井。 

地热初创公司GreenFire Energy的 GreenLoop 技术和Vallourec的真空绝缘管道解决方案是已经过测试的技术之一,但也有计划在实验室中测试 EGS 技术。

贝克休斯地热部门副总裁阿吉特·梅农 (Ajit Menon) 表示,该联盟的数据驱动方法已经带来了关于如何在不同情况下和不同流速下优化工作流体和最大化热传递的见解。 

新的野猫开发商:追逐热能的地热开发商
贝克休斯地热部门副总裁 Ajit Menon。(来源:贝克休斯

Menon 表示:“我们可以测试的东西有很多,包括工作流体、适用于恶劣环境的强大技术以及提高热效率的材料。”但他表示,并不是每个井都适合生产地热能,并指出,要找到具有足够热量的合适环境,需要进行大量的测绘工作。

“我们在这里看到了很多机会,特别是在这些新领域,你必须考虑优化你的注入和生产系统,以最大限度地减少流体损失并优化热量提取,”梅农说。“你必须同时将你产生的电力和地下发生的情况视为一个系统。”

该联盟的目标是在 2024 年从实验室走向实地。 

定制技术

梅农补充道,美国已经拥有地热发电的基础技术,但石油和天然气工具包中的工具必须针对地热发电进行定制。此外,地下和电力系统应作为一个整体进行优化。

“我们从事油井建设[和]地下作业,但我们也从事发电。我们在这里看到了很多机会,特别是在这些新领域,你必须考虑优化注入和生产系统,以最大限度地减少流体损失并优化热量提取,”梅农说。

他补充说,还要考虑速度,以减少恶劣环境下的开支。

“你需要能够有效地管理成本。因此,这实际上是在适应我们今天拥有的技术,不仅是技术,还有流程——将多年来开发的经过实践检验的流程引入地热领域,以将石油和天然气行业扩展到地热领域,”他说。

Sage Geosystems 首席执行官 Cindy Taff 对此表示同意。

总部位于休斯顿的Sage 公司重新进入壳牌位于德克萨斯州斯塔尔县的一口旧天然气勘探井,并在 2021 年和 2023 年的测试中证明其可以成功产生能源,从而 声名鹊起。

该公司的技术包括将大量的水泵入由裂缝形成的人工水库,以从炎热干燥的岩石中获取热量。压力使水库膨胀并保持水压。当需要电力时,水会被带回地面,涡轮机将热量转化为电能。

“我们像气球一样操作压裂。我们希望低渗透率,也希望避免任何类型的自然断层和裂缝,”壳牌前非常规油井和物流副总裁塔夫说。“石油和天然气实际上正在寻找相反的东西。他们想要高渗透率,他们想要那些自然断层和裂缝,这些往往会将碳氢化合物带到油井。”

新的野猫开发商:追逐热能的地热开发商
Sage Geosystems 首席执行官 Cindy Taff。(来源:Sage Geosystems

谈到改造旧油气井,塔夫说,地热井的直径需要是油井直径的两倍左右。此外,人们永远不知道重新进入旧井时会遇到什么情况。

“当我们重新进入斯塔尔县的测试井时,我们可能额外花费了 100 万美元来修复井,使其完整性达到标准,”她说。“你最好钻一口新井,并拥有一个全新的井眼。”

能够以经济高效的方式在商业规模上将热能转化为电能是当今地热能开发商面临的任务。

“在 Sage 看来,现在的挑战是热力学和地质力学方面的挑战,基本上就是将岩石中的热量释放到地面,”以便经济高效地将热量转化为电能,Taff 说道。“我们正在研究井设计和发电厂设计。我们认为这两者都至关重要。” 

Sage 计划于 2024 年底在德克萨斯州启用世界上第一个商业规模的地压地热系统。该公司还与圣安东尼奥西南研究所合作,建造了一台设计转速为 22,000 rpm 的超临界 CO 2涡轮机。负载测试定于 4 月下旬进行,目的是证明涡轮机从地面提取的单位热量产生的电力比目前地热使用的涡轮机更多。

“尽管美国拥有世界上最大的地热发电量,但它仍不到我们公用电网发电量的 1%。而且所有这些都是传统的地热……靠近地球表面的蒸汽,”靠近火山或火环,塔夫说。 

这还不到世界地热资源的 5%。她说,利用当今的石油和天然气设备,下一代地热能可以开采出美国 35% 至 40% 地区约 150 摄氏度的地热资源。

大约15到20年后,“如果我们能够真正破解让地热具有商业可行性的密码,我认为地热将占据公用电网的20%到25%”,塔夫补充道。

如果不能在增强型地热系统和增强型地热系统方面取得成功,地热的规模化发展就无法实现。梅农表示,随着先行者进入该领域,该行业的渗透率和钻井学习曲线已经有所改善。 

美国能源部资助的犹他州地热能研究前沿观测站 (FORGE) 项目是一个国际现场实验室,由犹他大学能源与地球科学研究所管理。该项目的工作(包括与 Fervo 合作)改善了成本、井口刺激和钻井时间——所有这些领域在过去都对地热的发展构成了挑战。

 

降低成本

新的野猫开发商:追逐热能的地热开发商
Fervo Energy 在犹他州 400 兆瓦 Cape Station 项目中钻探了一口垂直井和六口水平井,钻井速度比其在内华达州北部的 Project Red 钻井速度更快。(来源:Fervo Energy

Fervo Energy的投资者包括Devon EnergyHelmerich & Payne,该公司使用现代石油和天然气钻井设备,在犹他州 Cape Station 钻井活动中将钻井时间缩短了 70%,相比之下,2022 年在内华达州北部进行的 Project Red 钻井活动缩短了 70%。这些设备包括聚晶金刚石紧凑型钻头和泥浆冷却器。

在一个六口井钻探项目中,前四口井的成本下降了约 50%,从每口井 940 万美元降至 480 万美元。该项目包括一口垂直井,在高温下钻至 14,000 英尺深。

新的野猫开发商:追逐热能的地热开发商
Fervo Energy 首席执行官 Tim Latimer。(来源:Fervo Energy

Fervo Energy 首席执行官蒂姆·拉蒂默 (Tim Latimer) 表示,该公司穿越高温热岩花岗岩的钻井时间同比从 70 天缩短至 20 天。

他在标普全球举办的剑桥能源研究周 (CERAWeek) 上表示,学习曲线和生产力提升解锁了美国页岩油气的生产,使其成为全球最大的油气生产国。 

他说道:“我认为我们已经可以明确证明同样的趋势也将出现在地热领域。”

该公司正在犹他州比弗县建设一个 400 兆瓦的公用事业规模地热项目。第一阶段预计将于 2026 年底上线,第二阶段预计将于 2028 年上线。

“目前一切进展顺利。我们正在进行地下开发。我们正在采购发电厂并进行建设,”Fervo 的 Jewett 说道。

美国能源部的格特勒在讨论地热发射报告时表示,钻井时间一直在不断改善,而这些改进已经转化为成本的大幅降低。

“最近,一些地热初创公司发布的报告显示,早期部署使钻探速度提高了 300%,同时成本降低了一半。……所有这些进步都体现在最近的成本降低和地热技术成本预测中,”格特勒说。

美国能源部的增强型地热发射计划旨在到 2035 年将增强型地热系统的成本削减 90% 至每兆瓦时 (MWh) 45 美元。他说,这些改进主要通过井刺激和提高流速来推动,表明 EGS 目标虽然激进,但可以实现。

起飞目标对应的是,在没有政府补贴的情况下,能源的平准化成本(或者说终生成本)达到 60 美元/兆瓦时至 70 美元/兆瓦时。 

新的野猫开发商:追逐热能的地热开发商
EGS 的成本削减瀑布图。(资料来源:美国能源部商业化起飞之路:下一代地热发电

“如果你看看市场需求方面,你会看到……美国清洁能源的结算价为每兆瓦时 100 美元。而当你走向国际时,这个乘数通常要大得多,”拉蒂默说。“所以,它已经是一种相当具有成本竞争力的能源……地热能源已经在成本讨论中胜出。”

朱厄特说,过去,地热能源行业从未真正实现过基于规模的成本效益。她说,地理限制阻碍了公司钻探多个井、进行重复作业以及利用规模经济通过学习降低成本。 

“我们正试图彻底改变这种状况,”她补充道。

钻探就是一个典型的例子。

仅钻 6 到 10 口井很难获得任何有意义的学习。从地下开发的角度运用制造业思维可以带来有意义的改变。

“我们钻的井不只是 6 口或 10 口,而是 100 口。因此,我们基本上能够将每一口井的经验应用到以后的井中,”Jewett 说道。

更深、更热

钻探技术的进步可以使从超热岩石中获取更多能量成为可能。

在与 Fervo 的 Latimer 共同参加的同一个 CERAWeek 小组讨论中,清洁空气任务组 (CATF) 超热岩能源项目总监 Terra Rogers 表示,该项目专注于将地热温度提高到 400 摄氏度或更高。

CATF今年推出了地图,显示钻井人员必须钻多深才能实现这一目标。其建模工具显示,只需利用地下 1% 的超热岩石,即可产生 63 太瓦的清洁能源。大多数钻井人员都没有利用超热岩石,这种岩石通常位于美国地下 8 英里(12.5 公里)以下的深度,而现有钻机的强度和压力可能已达到极限。

“我们知道温度可以达到 400 度……但我们不知道的是,我们能否以一种经久耐用的方式完成或真正建造出这么好的管道,”罗杰斯说。“这也是研究成分中非常重要的一部分。……我曾听服务供应商说,7 公里的管道连眼睛都不眨一下。”

Evor 专门研究闭环地热技术,正在开发更深、更热的技术。

新的野猫开发商:追逐热能的地热开发商
Eavor Technologies 首席执行官 John Redfern。(来源:Eavor Technologies

“我们正在努力,但我们不会谈论它,” Eavor Technologies首席执行官 John Redfern 在同一场座谈会上表示。“就像我说的,更深、更热、更快、更便宜。这是我们的口号。而且,这些 [技术] 将会随着它们的出现而揭晓……7 到 9 公里是 [现在] 的极限。” 

雷德芬表示,该公司计划在今年晚些时候向电网输送第一批电力。

这家总部位于阿尔伯塔省卡尔加里的公司还与阿尔伯塔省政府和其他利益相关者联合开发了阿尔伯塔钻井加速器 (ADA),一个“与技术无关、市场驱动的地热试验场”。

据新闻稿称,加拿大首个此类试验场将可供任何寻求新型钻探技术和技术开发的地热公司使用。ADA 还旨在帮助该省跟上其他政府支持的地热试验场的步伐,例如犹他州 FORGE、德国大陆深层钻探计划、冰岛深层钻探项目和中国的地热钻探计划。

腾飞并实现规模化

美国能源部表示,美国有望在少数几个州生产高达 5 千兆瓦 (GW) 的清洁能源电力。但到 2030 年,要达到这一电力门槛,需要投资 200 亿至 250 亿美元。到 2050 年,要在更多州生产 88 千兆瓦至 125 千兆瓦的电力,可能还需要投资 2500 亿美元。

然而,如果氢气和直接空气捕获难以商业化并导致更多的地热开发,那么全国的装机容量可能会超过 300 GW,地热起飞报告的首席合著者、美国能源部清洁能源示范办公室战略家迈克尔·奥康纳 (Michael O’Connor) 表示。奥康纳和格特勒在今年早些时候的一次网络研讨会上讨论了下一代地热发电的潜力以及该部门的商业起飞报告途径。

报告中详述的地热能起飞的关键推动因素包括将成本降低至 60 美元/兆瓦时至 70 美元/兆瓦时,开展至少 30 多个兆瓦级的示范项目以证明一致性和降低技术风险,与公用事业或离网需求源(例如支持新项目的数据中心)签订高价值的承购协议,以及选择场地并与社区一起开发项目。

“在能源部运营的犹他州 FORGE 站点,地震监测器实际上在公共图书馆展出。因此,社区成员可以实时透明地看到钻井和钻井活动对其社区的影响,”O’Conner 说道。

报告称,实现这一目标的途径包括在 5 到 10 个不同的地质环境中进行地热示范,以降低风险并验证资源可用性。这相当于 100 多个开发项目,总部署容量为 2 吉瓦到 5 吉瓦,成本为 200 亿到 250 亿美元。要实现规模化,还需要更多,规模定义为 88 吉瓦到 125 吉瓦之间。

新的野猫开发商:追逐热能的地热开发商
商业化起飞和规模化的途径。地图上的绿点代表了地热发电的潜在足迹。(来源:美国能源部商业化起飞的途径:下一代地热发电

美国能源部表示:“要到2050年达到规模,下一代地热能将需要额外的2250亿至2500亿美元的投资,由开发商、投资者、公用事业公司和其他承购商组成的新生态系统推动,并利用现有的劳动力和供应链。”

Jewett 表示,发展地热的最大障碍可能是说服人们为项目提供资金。对于 Fervo 来说,“只要他们打开引擎盖,看到这些是具有长期寿命的良好基础设施回报项目,就不需要费多大力气说服他们了,”她补充道。“我们是一家不像过去的地热公司那样到处钻探,然后一无所获的公司。我认为我们是一家计划周全、执行力强的公司。”

当投资者看到这一点时,“他们很容易就被说服了”。

在 CERAWeek 会议小组讨论转向资金问题时,拉蒂默和雷德芬指出了他们的公司如何成功筹集风险投资资金来开展项目。

雪佛龙和 Fervo 获得了美国能源部由《两党基础设施​​法案》资助的地热项目拨款。

拉蒂默说:“那里有资金,这很好,而且足以……在董事会上增加一些分数,并为我们的行业带来一些胜利。” 

另一方面,发射报告中的一张图表比较了地热能与其他技术获得的资助。 

雷德芬说:“我在条形图上看不到条形图”,并指出尽管如此,资金不会阻碍地热能的发展。

新的野猫开发商:追逐热能的地热开发商
清洁空气任务组超热岩能源项目总监 Terra Rogers。(来源:清洁空气任务组

“随着我们不同项目的验证,就会有大量资金想要投资,”他说。“阻碍我们发展的是扩大规模的物理限制……因为组织人员需要时间。消除钻井平台方面的瓶颈也需要时间。发展速度受到一系列物理限制。”

罗杰斯表示,技术合作伙伴是地热故事中被忽视的部分。

“谷歌和微软在拉开绿色帷幕、承认需求和供应需要协调一致(尤其是在这个领域)以及努力满足低碳期望和这些超大型数据中心给电网带来的压力方面做得非常出色,”她说道。“因此,随着人们逐渐意识到它们是购买链的重要组成部分,如果我们看到一些垂直整合,我不会感到惊讶。但无论如何,它们肯定是一个强大的资金来源。我们不能只做其中一件事而不做另一件事。”

原文链接/HartEnergy

The New Wildcatters: Geothermal Developers on the Hunt for Heat

The U.S. is poised for a geothermal boom using existing oil and gas technology. Does the industry have what it needs to scale?

Houston-based Fervo Energy set record power and flow rates in 2023 at its Project Red enhanced geothermal project in northern Nevada, confirming the commercial viability of its drilling technology. (Source: Fervo Energy)

To say the geothermal industry is heating up in the U.S. might be an understatement.

Once shunned by potential investors due to project failures, poor planning and other investment risks, geothermal company leaders and others in the energy sector are turning the situation around.

And they are using techniques from oil and gas company playbooks. Think horizontal drilling and multi-well pads. Oilfield service companies are unearthing new ways to use their products, such as insulated tubing to minimize heat loss and maximize energy as fluids in geothermal wells move from the subsurface to the surface.

Experts say the technology is there, though tweaks may be needed.

“It’s a common misconception that all this innovation needs to happen in order to bring geothermal power to market. But … we have all of the technology we need,” Sarah Jewett, vice president of strategy for Fervo Energy, told E&P. “We have a pretty massive and robust customer set. So, the only thing we have to do is build the projects and deliver to the market.”

Still, roadblocks remain on the path to commercial scale. Although upfront costs are falling, they remain high. Capital constraints and financing concern some. And, geothermal is no exception to the federal permitting and grid interconnection woes the entire energy industry faces.

Hot reservoirs

Geothermal energy harnesses heat below ground using wells drilled into hot reservoirs. Conventional geothermal does not require much engineering to capture heat because it’s closer to the surface, with naturally occurring fractures and fluid, such as in volcanic areas.

Next-generation geothermal energy, however, uses existing oil and gas technologies to harness heat and unlock geothermal energy from anywhere. With an enhanced geothermal system (EGS), fluid is circulated in a pair of wells connected by fractures created in hot reservoirs. Closed-loop geothermal systems, also referred to as advanced geothermal systems, circulate fluids through closed wellbore loops in the subsurface. The heat extracted can be used to heat or cool homes and buildings via direct use heat or generate electricity with higher temperature geothermal resources.

In addition to supplying a renewable energy source, geothermal power plants provide baseload power—meaning they consistently produce electricity—regardless of weather conditions. The renewable energy source can be used to store energy underground, and the footprint required is relatively small compared to solar and wind sources of renewable energy.

It has the potential to replace or at least reduce the number of coal- and gas-fired power plants with renewable energy.

“Next-generation geothermal power is poised to become a key contributor to a secure domestic decarbonized power sector in the United States. This is an industry that is ready to grow to large scale,” said Charles Gertler, a senior advisor for the U.S. Department of Energy (DOE) Loan Programs Office and a lead co-author of the “Pathways to Commercial Liftoff: Next-Generation Geothermal Power” report.

“There is a set of emerging technology that is just coming online that vastly expands the total resource available for geothermal power generation,” he said during a webinar discussing the report earlier this year. “The sector overall has really significant and unique starting advantages.”

That includes the oil and gas industry, which has been pumping both dollars and technical knowhow into geothermal.

The O&G effect

Oil and geothermal drillers have loads in common. Geothermal developers, like wildcatters, hunt for heat. They carry out site assessments using sensors and other geological aids and evaluate reservoirs. Downhole tools, pumps and turbines are also part of the process as are hydraulic fracturing tools and injection pumps for EGS. So, it may not be too surprising to see oil and geothermal drillers working together to bolster geothermal.

Service company Baker Hughes has been in the geothermal business for about 40 years, providing services that include geothermal well construction, reservoir subsurface and feasibility analysis, and turbine technology for geothermal power generation. Part of its current efforts focus on closed-loop systems as part of the Wells2Watts consortium

With partners California Resources Corp., Chesapeake Energy, Continental Resources and Inpex Corp., Baker Hughes is looking to retrofit decommissioned oil and gas wells and use existing infrastructure to create closed-loop geothermal wells. 

Geothermal startup GreenFire Energy’s GreenLoop technology and Vallourec’s Vacuum Insulated Tubing solutions are among the technologies that have been tested, but there also are plans to test EGS technologies in the lab.

The consortium’s data-driven approach has already led to insights on how to optimize the working fluids and maximize heat transfer in different situations and with varying flow rates, according to Ajit Menon, vice president of geothermal for Baker Hughes. 

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Ajit Menon, Vice President of Geothermal, Baker Hughes. (Source: Baker Hughes)

“There’s a whole list of things that we can test,” Menon said, referring to working fluids, robust technology for harsh environments and materials that improve heat efficiency. But not every well is suitable to produce geothermal energy, he said, noting that finding the right environment with enough heat requires a great deal of mapping work.

“We see a lot of opportunity here, especially in these new frontiers where you have to look at the optimization of your injection and production system to minimize fluid loss and optimize heat extraction,” Menon said. “You have to look at the power you’re generating and what’s happening on the subsurface all as one system together at the same time.”

The consortium aims to move from the lab to the field in 2024. 

Customizing technology

Base technologies are available for geothermal to scale in the U.S., but tools from the oil and gas toolkit must be customized for geothermal, Menon added. And, subsurface and power systems should be optimized as one.

“We’re in well construction [and] subsurface, but we’re also in power generation. We see a lot of opportunity here, especially in these new frontiers where you have to look at the optimization of your injection and production system to minimize fluid loss and optimize heat extraction,” Menon said.

There’s also an eye toward speed, which decreases expenses in harsh environments, he added.

“You need to be able to manage that cost effectively. So, it’s really adapting technology we have today, and not just technology but processes—bringing tried and true processes that have been developed over the years to scale the oil and gas industry into geothermal,” he said.

Sage Geosystems CEO Cindy Taff agrees.

Houston-based Sage gained prominence after it reentered one of Shell’s old gas exploration wells in Starr County, Texas, and proved during testing in 2021 and 2023 that it could successfully generate energy. 

Its technology involves pumping large volumes of water into an artificial reservoir created by a fracture to harvest heat from hot dry rock. Pressure causes it to balloon open and hold the water under pressure. When electricity is needed, the water is brought back to the surface, where a turbine converts the heat to electricity.

“We operate fracturing like a balloon. We want low permeability, and we also want to avoid any kind of natural faults and fractures,” said Taff, a former vice president of unconventional wells and logistics for Shell. “Oil and gas is actually looking for just the opposite. They’re wanting the high permeability, and they’re wanting those natural faults and fractures, which tend to bring the hydrocarbons to the wells.”

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Cindy Taff, CEO, Sage Geosystems. (Source: Sage Geosystems)

When it comes to repurposing old oil and gas wells, Taff said geothermal wells need a diameter that is about double that of oil wells. Plus, one never knows what might be encountered when reentering an old well.

“When we reentered our test well in Starr County, we spent probably an extra $1 million fixing the well to bring the integrity up to snuff,” she said. “You’d be better off drilling a new well and having a brand-new wellbore.”

Being able to turn the heat into electricity cost-effectively and at commercial scale is the task at hand for geothermal energy developers today.

“In Sage’s view, the challenge is now the thermodynamics and geomechanics challenges of basically getting the heat out of the rock, getting it to the surface,” to cost-effectively turn heat into electricity, Taff said. “We’re looking at both the well design and the power plant design. We think both of them are crucial.” 

Sage aims to commission the world’s first commercial-scale geopressured geothermal system by the end of 2024 in Texas. It has also worked with the Southwest Research Institute in San Antonio to build a supercritical CO2 turbine designed for 22,000 rpm. A load test was scheduled for late April with ambitions to demonstrate that the turbine can produce more electricity per unit heat extracted from the ground than turbines being used in geothermal today.

“Even though the U.S. has the largest amount of geothermal generation in the world, it’s still less than 1% of our utility grid generation. And it all is represented by, again, conventional geothermal … steam close to the surface of the Earth,” near volcanoes or the Ring of Fire, Taff said. 

That’s not even 5% of the world’s geothermal resources. Using today’s oil and gas equipment, next-gen geothermal could unlock geothermal resources at about 150 C for about 35% to 40% of the U.S., she said.

About 15 to 20 years from now, “if we can literally crack the code on making [geothermal] commercially viable, I think geothermal is going to represent 20 to 25% of the utility grid,” Taff added.

Scaling geothermal will not happen without success in EGS and AGS. The sector is already seeing improvements in the rate of penetration and drilling learning curves happening with first movers in the space, Menon said. 

The DOE-sponsored Utah Frontier Observatory for Research in Geothermal Energy (FORGE) project is an international field laboratory managed by the Energy & Geoscience Institute at the University of Utah. Its work, including with Fervo, has enabled improvements in costs, well stimulation and drilling times—all areas that have challenged geothermal’s growth in the past.

 

Driving down costs

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Fervo Energy drilled one vertical well and six horizontals at its 400-MW Cape Station project in Utah, drilling wells faster than it achieved with Project Red in northern Nevada. (Source: Fervo Energy)

Fervo Energy, which counts Devon Energy and Helmerich & Payne among its investors, reduced drilling time during its Cape Station in Utah drilling campaign by 70% compared to its 2022 Project Red drilling campaign in northern Nevada, using modern oil and gas drilling equipment. These included polycrystalline diamond compact drill bits and mud coolers.

In a six-well drilling program, costs for the first four wells dropped by about 50%, from $9.4 million to $4.8 million per well. The campaign, which included one vertical well, reached depths as great as 14,000 ft amid high temperatures.

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Tim Latimer, CEO, Fervo Energy. (Source: Fervo Energy)

Fervo Energy CEO Tim Latimer said the company reduced its year-over-year drilling time through high-temperature hot rock granite from 70 days to 20 days.

The learning curve and productivity gains unlocked shale oil and gas production in the U.S., making it the world’s largest oil and gas producer, he said during CERAWeek by S&P Global. 

“I think we’re well on our way to definitively proving that same trend is going to occur in the geothermal sector,” he said.

The company is constructing a 400-megawatt utility-scale geothermal project in Beaver County, Utah. The first phase is set to come online near the end of 2026 with the second phase expected online in 2028.

“It’s in full go mode right now. We’re doing subsurface development. We’re doing the procurement for the power facility and building it,” Fervo’s Jewett said.

DOE’s Gertler, discussing the geothermal liftoff report, said drilling times have consistently improved, and those improvements have translated into significant cost reductions.

“There are some reports from geothermal startups recently that show early deployments demonstrating a 300% increase in drilling rate, and in the process, cutting costs in half. ... All of these advancements taken together can be seen in recent cost reductions and on projections of costs for geothermal technologies,” Gertler said.

The DOE’s Enhanced Geothermal Shot initiative aims to slash the cost of enhanced geothermal systems by 90% to $45 per megawatt hour (MWh) by 2035. The improvements, driven mainly by well stimulation and improved flow rates, show the EGS target is aggressive but achievable, he said.

The liftoff target corresponds to a levelized cost—or the lifetime costs—of energy of $60/MWh to $70/MWh, without help from government subsidies. 

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Cost reduction waterfall for EGS. (Source: U.S. Department of Energy’s Pathways to Commercial Liftoff: Next-Generation Geothermal Power)

“If you look at the market demand side, what you’re seeing … is that firm clean power in the United States is clearing at $100 a MWh. When you go internationally, it’s often a much bigger multiplier than that,” Latimer said. “So, it’s already something that’s quite cost competitive … geothermal is already winning that cost discussion.”

In the past, the geothermal energy industry had never seen real cost efficiencies based on scale, Jewett said. Geographical constraints have prevented companies from drilling multiple wells, carrying out repetitive operations and leveraging economies of scale to reduce costs through learning, she said. 

“We’re trying to basically upend that,” she added.

Drilling is a prime example.

It is difficult to achieve any meaningful learning by drilling only six to 10 wells. Applying a manufacturing mindset from a subsurface development perspective can lead to meaningful change.

“We are drilling not six or 10 wells, but we’re drilling a 100 wells. So, we’re basically able to apply the learnings of every single well to the wells thereafter,” Jewett said.

Going deeper, hotter

Drilling advances could make harnessing more energy from superhot rock possible.

Speaking during the same CERAWeek panel with Fervo’s Latimer, Terra Rogers, program director for superhot rock energy at the Clean Air Task Force (CATF), said it is focused on moving geothermal into temperatures of 400 C or higher.

CATF rolled out maps this year that show how deep drillers must go to make this possible. Its modeling tool showed 63 terawatts of clean power could be generated by harnessing just 1% of superhot rock belowground. Most drillers are not tapping into superhot rock, which is typically found in the U.S. at depths below 8 miles (12.5 km), a point at which existing rig capacity may be maxed out in terms of strength and stress.

“We know that we can get to 400 degrees …. What we don’t know we can do is complete or really construct that well in a way that has longevity,” Rogers said. “That is also a very important part in the research ingredients. … I have heard service providers say 7 km without blinking an eye.”

Eavor, which specializes in closed-loop geothermal technology, is developing technologies to go deeper and hotter.

The New Wildcatters: Geothermal Developers on the Hunt for Heat
John Redfern, CEO, Eavor Technologies. (Source: Eavor Technologies)

“We’re working on it, but we’re not going to talk about it,” Eavor Technologies CEO John Redfern said during the same panel. “Like I say, deeper, hotter, faster, cheaper. That’s our mantra. And, those [technologies] will be unveiled as they come along … 7 to 9 km is sort of the limit [now].” 

The company aims to deliver first power to the grid later this year, Redfern said.

The Calgary, Alberta-based company also joined the Alberta government and other stakeholders to develop the Alberta Drilling Accelerator (ADA), a “technology-agnostic, market-driven geothermal test site.”

The first-of-its-kind site in Canada will be available for use by any geothermal company pursuing novel drilling techniques and technology development, according to a news release. The ADA also aims to help the province keep pace with other government-supported geothermal test sites, such as Utah FORGE, the Continental Deep Drilling Program in Germany, the Deep Drilling Project in Iceland and China’s geothermal drilling program.

Lifting off, achieving scale

The DOE says the U.S. is positioned to produce up to 5 gigawatts (GW) of the clean energy power source across a handful of states. But it will take between $20 billion and $25 billion in investments to reach that power threshold by 2030. Producing 88 GW to 125 GW across more states by 2050 could require as much as another $250 billion.

Capacity could surpass 300 GW across the country, however, if hydrogen and direct air capture become difficult to commercialize and lead to more geothermal development, according to Michael O’Connor, lead co-author of the geothermal liftoff report and strategist for DOE’s Office of Clean Energy Demonstrations. O’Connor and Gertler discussed the potential for next-generation geothermal power and the department’s pathways to commercial liftoff report during a webinar earlier this year.

Key enablers for geothermal liftoff as detailed in the report include reducing costs to $60/MWh to $70/MWh, carrying out at least 30+ megawatt-scale demonstration projects to prove consistency and lower technology risk, locking in high-value offtake agreements with utilities or off-grid demand sources such as data centers that support new projects, and selecting sites and developing projects with communities.

“At the DOE-run Utah FORGE site, seismicity monitors are actually on display at the public library. So, community members can transparently see the impacts of drilling and drilling activities in their community in real time,” O’Conner said.

The pathway to liftoff includes demonstrating geothermal in five to 10 separate geologic settings to reduce risk and verify resource availability, according to the report. This corresponds to more than 100 developments, comprising overall deployment of 2 GW to 5 GW at a cost of $20 billion to $25 billion. Even more is required to achieve scale, defined as between 88 GW and 125 GW.

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Pathway to commercial liftoff and scale. Green dots on maps correspond to representative potential geothermal footprint in terms of power use. (Source: U.S. Department of Energy’s Pathways to Commercial Liftoff: Next-Generation Geothermal Power)

“To reach scale by 2050, next-generation geothermal will require an additional $225 to $250 billion in investment, driven by a new ecosystem of developers, investors, utilities, and other offtakers, and leveraging existing workforces and supply chains,” according to the DOE.

The biggest roadblock for growing geothermal may be convincing people to finance projects, according to Jewett. For Fervo, “it doesn’t take a ton of convincing once they lift up the hood and they see that these are good infrastructure-type return projects with long lifetimes,” she added. “We are a company that is not like geothermal companies of yore where we’re going to sort of drill all over the place and then come up empty. I think we’re a company that plans very well and plans to execute.”

When investors see that, “they become convinced pretty easily.”

As the discussion turned to funding during the CERAWeek session panel, Latimer and Redfern pointed out how their companies have been successful in raising venture capital dollars to pursue projects.

Chevron and Fervo received grants from the DOE for geothermal projects funded by the Bipartisan Infrastructure Bill.

“It’s good there’s funding there and enough to … put some points on the board and show some wins for our sector,” Latimer said. 

On the flip side, a chart in the liftoff report compares how much funding geothermal received compared to other technologies. 

“I couldn’t see the bar on the bar chart,” Redfern said, noting that despite that fact, funding will not hold back geothermal.

The New Wildcatters: Geothermal Developers on the Hunt for Heat
Terra Rogers, Program Director for Superhot Rock Energy, Clean Air Task Force. (Source: Clean Air Task Force)

“As we prove up our different projects, there’s going to be a wall of money that wants to invest,” he said. “What’s going to hold us back is a physical limit of how fast we can scale up ourselves … because it just takes time to get people organized. It takes time to get rid of bottlenecks on the drilling rig side. There’s a whole bunch of physical limitations to how quickly you can grow.”

Rogers said tech partners are the unsung part of the geothermal’s story.

“Google and Microsoft have done an excellent job of pulling aside the green curtains and acknowledging that demand and supply need to align, especially in this space, and trying to match low-carbon expectations and the stress that these hyper-sized datacenters put on grids,” she said. “So as there is an awakening to the idea that they are a big part of the buying chain, I wouldn’t be surprised if we see some vertical integration. But in any case, they certainly are a strong source of funds. We don’t do one without the other.”