浙侨英频 | Deep Earth sciences key to development

Technicians closely observe operations of the record-breaking Crust 1, one of China's most-advanced onshore drilling rigs. [Photo provided to China Daily]

Nation has intensified research projects for exploration, discovery

China will need to enhance research into deep Earth sciences to fulfill some of the country's biggest strategic needs, from finding and utilizing underground resources to predicting and mitigating natural disasters, experts said.

In a speech addressing China's top scientists and engineers in late May, President Xi Jinping urged the Chinese scientific community to break new ground in four strategic frontiers: deep space, deep sea, deep Earth and "deep blue".

"Deep blue" refers to fields related to computer science and information technology, such as cyberspace security and artificial intelligence, according to the Ministry of Science and Technology, while deep Earth consists of geology, mineralogy, seismology, geothermal energy and other sciences related to understanding the Earth's internal structure and utilizing its resources.

Compared with the other three frontiers, deep Earth exploration is a relatively obscure field, given the enormous resources, manpower and technological ingenuity needed to penetrate the Earth's crust, experts said. But since the mid-20th century, more countries are now aware of the strategic importance of this field.

Liu Jiaqi, a geophysicist and an academician of the Chinese Academy of Sciences, said deep Earth sciences are closely related to the ability to tap into Earth's mineral and energy resources. They also play a key role in environmental protection and mitigating the risks of natural disasters, such as earthquakes and volcano eruptions.

"It is a science about supporting and sustaining life on Earth. Without it, we cannot thrive," he said, adding that China's long-term economic prosperity depends heavily on the supply of fossil fuels and basic raw ingredients, all of which are created via complex geological activities and extracted from the ground.

Xu Yigang, a geochemist and a CAS academician, said China attaches such great importance to deep Earth exploration because the country needs to curb its overreliance on importing iron, copper, nickel, oil and natural gas.

"Therefore, we need to strengthen our basic research into deep Earth sciences so that we can find and mine the resources our country needs," he said.

Taking iron ore as an example, many of the world's largest and most accessible iron ore mines are in Australia, Brazil and Russia, according to the Ministry of Commerce. Although China has the world's fourth-largest crude iron ore reserves, most of the ore is deep underground and too costly to mine and process.

As a result, China has had to import nearly 80 percent of its iron ore since 2011, the ministry said, adding that the country has also been the world's biggest importer of copper and nickel for years, fueled by the country's rapid development in stainless steel, construction and electronics.

The lack of self-sufficiency in these raw ingredients means Chinese industries are strongly affected by price fluctuations. On May 12, the price of iron ore surged to a record $237.57 per metric ton, prompting the China Iron and Steel Association to take measures to curb the rising price and ensure stability of the supply chain.

Luo Tiejun, vice-president of the association, warned at a conference in December that the price of iron ore had been climbing rapidly in 2020, which surpassed industry expectations and introduced new risks and instabilities to the economy.

Forging ahead

Since the 1960s, drilling deep boreholes has been a crucial scientific tool for investigating the evolution, composition and physical movement of Earth, according to the International Continental Scientific Drilling Program.

As a result, scientists often dub these boreholes "telescopes into Earth".

In 2005, China completed its first continental scientific borehole, reaching 5,158.2 meters below the Dabie-Sulu continental collision zone in eastern China, according to the China Geological Survey. This feat made China the third country in the world, after Russia and Germany, to drill deeper than 5,000 meters.

The deepest borehole to date is the 12.2-kilometer Kola Superdeep Borehole in Russia. However, Liu said this depth is barely scratching the surface when it comes to exploring the internal structure of Earth, which has a radius of more than 6,370 kilometers.

In recent years, China has intensified its research into probing the Earth, Liu said. In 2009, the Ministry of Land and Resources, the predecessor of the Ministry of Natural Resources, launched a research initiative dedicated to deep Earth drilling technologies. This was followed by another major research program by the Ministry of Science and Technology in 2016 that focused on extracting underground resources.

Chinese scientists are also planning a new deep Earth science research project, with hopes it will be added to the nation's list of Science and Technology Innovation 2030－Major Projects, which currently includes 16 objectives ranging from brain sciences to artificial intelligence.

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【背景阅读】

“地壳一号”钻机：将人类“视距”延伸至地下万米

7018米！

2018年6月2日，由我国自主研发的万米钻机“地壳一号”正式宣布完成“首秀”：以完钻井深7018米创亚洲国家大陆科学钻井新纪录，标志着中国成为继俄罗斯和德国之后，世界上第三个拥有实施万米大陆钻探计划专用装备和相关技术的国家，这让参与其中的科研人员激动不已。

为满足我国地球深部探测工程的重大需求，我国于2009年启动了“深部探测技术与实验研究专项”，其中第九项目“深部探测关键仪器装备研制与实验”由吉林大学教授、博士生导师黄大年担任负责人，该项目的第五课题“深部大陆科学钻探装备研制”由时任吉林大学副校长、教授孙友宏担任负责人，该课题的主要任务是研制“地壳一号”万米钻机。

2013年10月15日，50辆大型拖车装载着被分拆成零件的“地壳一号”从四川省广汉市出发前往东北；2014年4月13日零点，“地壳一号”万米钻机在位于松辽盆地的松科二井现场实施开钻作业；2018年，松科二井正式完井，超额完成预定目标，在理论、技术、工程、装备等方面均实现了重大突破，极大地提升了我国地球深部探测的能力和影响力。

进军

一场科技竞赛在地球内部展开

“上天、入地、下海、登极”是人类认识自然和挑战自然的四大壮举。以大陆科学钻探为主的“入地”工程是获取地下实物信息的唯一手段，其难度绝不亚于“上天”工程。

受困于地壳岩石阻隔，人类对地球内部知之甚少。若想对地球内部结构和物质成分进行探测，最直接、最有效和最可靠的方法是纵深向地球内部打一口科学钻探井，将人类的“视距”向地球内部延伸数千米甚至上万米，进而一探究竟。

通过科学钻探，在地质学方面，人们可以研究地球深部构造及演化、地球深部流体及其作用，校验地球物理探测结果；在资源能源开发利用方面，可以研究成矿理论、油气成因，调查和开发深部热能；在环境科学方面，可以研究地震成因、火山喷发机理、地质灾害预警、地球气候演变、生命演化历史。因此，科学钻探被形象地誉为了解地球内部信息的“望远镜”。

基于此，上世纪末一些先行者开始向地球深处“进军”。

大陆科学钻探工程开始于20世纪60年代初，苏联地质学家H.A.别里亚耶夫斯基等人根据深部地球物理资料提出，获取整个地壳剖面，至少要在全球6个地区打超深井。

1970年，由苏联科学家主导的科拉超深钻孔工程启动，其中最深的一个钻孔SG-3超深孔1986年3月达到11300米。与此同时，其他国家也开始了在这方面的探索，例如美国的罗杰斯1号孔（9583米，1974年）和德国的KTB井（9101米，1994年）。

1996年，国际大陆科学钻探计划（ICDP）正式成立以来，更多国家开始参与制定并组织实施科学钻探，加入到国际大陆科学钻探计划中来。此时，各国争先恐后的重要原因，在于以深井油气钻探装备为依托的大陆科学钻探工程，在一定程度上反映了一个国家的经济实力和科技发展水平。这是一场科技竞赛，谁也轻易不敢掉队。

而在那时，我国最深的科学钻探孔为CCSD-1孔，深度仅为5158米。

攻关

见招拆招解决“三高”难题

超深孔钻探面临一系列的世界级难题，其中最难以攻克的，便是要在地球的高温、高压、高地应力“三高”条件下，确保钻具的配件和电子元件能正常工作、取芯工作能够顺利进行。

为解决“三高”难题，我国的科技工作者们进行了艰苦卓绝的科研攻关。

经过4年多的努力，吉林大学成功研发出了我国首台万米大陆科学钻探专用装备——“地壳一号”万米钻机，解决了我国深部钻探装备转盘回转速度低、设备自动化程度低和深部钻探钻头压力控制精度低的三大技术难题，突破了高转速全液压顶部驱动钻进、高精度自动化摆排管、高速度钻杆柱自动拧卸输送和高精度自动送钻四大深部钻探装备关键技术，形成了具有自主知识产权的高性能深部科学钻探装备和配套装置，填补了我国在深部大陆科学钻探装备领域空白，大大提高了我国超深井科学钻探装备的技术水平。

“此外，‘地壳一号’万米钻机还应用了一套由我们研发的自动化钻井装置，其主要包括自动摆排管装置、自动拧卸装置、自动‘猫道’装置以及我们国内钻深能力最大的一台全液压顶驱装置。”吉林大学机械学院教授沙永柏说。

地球内部的高温泥浆，被誉为钻井的“血液”。在钻井过程中，井钻得越深，泥浆温度越高，钻探技术难度越大。

在对国内外近30家泥浆材料供应商的产品进行遴选和配方试验后，中国地质大学（武汉）工程学院勘察与基础工程系教授乌效鸣研制出一种超高温水基钻井液配方，使钻井设备可经受住240摄氏度以上的高温考验，刷新我国钻井液应用的最高温度纪录，给工程节省大量资金，保障了钻孔安全。

成就

相关成果服务“一带一路”

岩芯作为地下岩石的剖面截取物，是人类了解地球深部唯一的实物资料。取出岩芯后，地学家们通过技术手段对其进行分析研究，借此来了解地球的成因、研究古环境古气候的变化规律、研究地质构造运动、发现矿产资源和油气资源。

“高于96%的取芯率，获得了连续完整的4014米岩芯。”“地壳一号”工程项目取得的众多成果中，这一项被地质专家们津津乐道。

按照要求，从井中取出的圆柱形岩芯，无论大小，其每间隔10厘米或20厘米要贴上唯一的“身份证”编码，包括钻孔名称、回次号、岩芯段等信息。这些数据伴随岩芯一起被存入国家实物地质资料库。借助“地壳一号”万米钻机获得的这些岩芯，为我国科学家建立地球演化档案提供了难得的资料，也为大庆油田未来50年时发展和我国能源安全提供了重要的数据支撑。

松科二井工程首席科学家、中国科学院院士王成善说，松科二井完井是国际大陆科学钻探计划历程中一件大事，也是中国入地工程的一件标志性事件。实施这个工程最主要目的就是要探究距今6500万年至1亿4千万年期间，即白垩纪时期重大地质事件、烃源岩的生成与古环境古气候变化的奥秘。

据了解，目前“地壳一号”钻机的相关技术成果已经成功应用于我国低温钻机系列设备中，比如“极光”号极地钻机。

目前，“极光”号极地钻机已被应用在俄罗斯北极圈亚马尔高寒地区油气勘探作业中。亚马尔液化天然气项目是中俄能源合作的重大项目，是中国提出“一带一路”倡议后实施的首个海外特大型项目。

“极光”号极地钻机是应用于中俄亚马尔液化天然气项目的重要大型设备，该钻机可在零下50摄氏度低温和12级以上强风环境下连续工作。这也是我国制造的首台可以在零下55摄氏度环境作业的极地钻机。

“地壳一号”项目的技术成果还被广泛应用于深部油气钻机和海洋钻机钻井包中，应用其成果的相关设备出口到阿联酋、委内瑞拉、俄罗斯、美国等多个国家和地区。

相关行业专家表示，“地壳一号”万米钻机的研制及应用，标志着我国地学领域对地球深部探测的“入地”计划取得重大阶段性进展，为后续国家地壳探测工程的全面实施、探求地球深部奥秘提供了高技术手段，也将带动我国深部油气资源和地热资源勘探开发行业的技术进步。

来源|科技日报

原标题：《浙侨英频 | Deep Earth sciences key to development》

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