【经济学人】深入地底探索DNA新用途丨2017.03.16丨总第844期

WHAT lies beneath? It is a pressing question for those prospecting for oil, planning shale-fracturing or seeking geothermal-energy sites. Underground reservoirs of water, oil and gas are connected in extensive, circuitous networks that can change with time or with drilling. Knowing those networks’ particulars can make a big difference to beliefs about how much can safely be extracted from them.

地下到底有什么？对于那些勘探石油、开发地热能或者利用水力压裂开采页岩油的现场地点来说，这个问题显得非常急切。地下的水体、石油和天然气通过星罗棋布的“脉络”相连，可能会随着时间推移或者开采的进展而发生变化。详细了解这些网络的具体情况能够极大地帮助人们确定安全的开采上限。

• Prospect for： 勘探

• Shale： n. 页岩；泥板岩

• Drill：vt. 钻孔

To acquire such knowledge, drillers often use tracers. These are materials that can be injected into the ground in small amounts at one point and then detected reliably if they turn up in other places—thus showing that those places have subterranean links to the point of injection. The supply of decent tracers, however, is limited. About 100, mostly dyes or mildly radioactive materials, are in routine use. This constrains the number of possible injection points in a particular area, and thus the amount of tracking that can actually be done. Yet in many cases—for example, a long well that runs horizontally through a particular rocky stratum—more than 100 injection points might ideally be required. The numerical constraint on tracers extends, moreover, into time, as well as space, for injecting one poisons the well, as it were, thus confusing future attempts to employ the same agent.

为获取此类信息，钻探人员通常会使用示踪剂：将少量示踪剂在某一地点注入地下，然后检测示踪剂是否在其他地点出现。如果是，则说明这些地点与注入点存在地下连接。但是，想要找到一种良好的示踪剂十分困难。目前能够常规使用的示踪剂有大约100种，其中大部分都是染色材料或者具有轻微放射性。这就限制了特定区域可注入点的数量以及实际的可追踪量。而且在大多数情况下，注入点的数量都很多。举例来说，一个很长的探井沿特定岩层水平延伸，那么其需要的理想注入点会超过100个。此外，示踪剂的数量限制随着时间推移（以及空间的变化）变得越发严重，而且由于曾经发生过注入示踪剂导致探井遭到污染的事件，未来是否应该继续使用相同指示剂也存在争议。

• Tracer： n. 示踪物；追踪者；描图者；绘图工具

• Subterranean： adj. 地下的；秘密的；隐蔽的

• Stratum： n. （组织的）层；地层；社会阶层

• as it were：可以说是，似乎就是；好像

The problem would go away, though, if a tracer could be found that was essentially the same with every use, and would thus behave in a predictable way, but was different in detail on each occasion, so that both the time and the place of its injection could be known reliably when it turned up elsewhere. And such a substance exists. It is called DNA. The four types of chemical “letter” of which this molecule is composed can be written in any order you like, giving infinite variety to individual batches of the stuff. Unfortunately, DNA is a delicate molecule, ill-equipped to survive the extreme temperatures and stresses found inside boreholes. Attempts in the 1990s, by Statoil, Norway’s state-owned fossil-fuel company, to use it as a tracer failed. But technology has moved on, and others are now trying again.

不过，如果能够找到一种理想的示踪剂，问题就迎刃而解了：它应当不会因多次使用而发生变化，既可预测又在每次使用时有着细节上的不同，无论在何处出现都能确切地知晓其注入时间和地点。这种物质其实是存在的，它就是DNA。DNA分子由四种脱氧核苷酸组成，这四种组分可按照任意顺序排列，其组合方式无穷无尽。不幸的是，DNA过于脆弱，适应性不强，无法适应钻井中的极端温度和压力。早在二十世纪九十年代，挪威的国有化石燃料企业Statoil就试图利用DNA作为示踪剂，不过未能成功。但随着科技的发展进步，人们又开始了新一轮的尝试。

• Batch：n. 一批；一炉；一次所制之量

• Ill-equipped adj. 装备不良的

• Borehole：n.地上凿洞

One such is BaseTrace, in North Carolina. This firm’s engineers exploit the fact that some DNA sequences are more stable than others. Such relative stability comes from the various ways that different DNA molecules fold up—their so-called secondary structures. But any given secondary structure can have numerous underlying sequences, so there is plenty of room for multiple tracer molecules that have the same properties of stability. BaseTrace has used this to develop algorithms which work out what sequences are best for the stresses a given application presents. It has recently moved from courting the oil industry to nuclear energy, where conditions of wastewater are at their most extreme.

位于北卡罗来纳州的 BaseTrace 就是尝试者之一。该公司的工程人员经过研究发现，某些DNA序列要比其它序列更为稳定。导致这种相对稳定性的原因是DNA分子的组成结构，即二级结构各有不同。但是，指定的二级结构可能具有很多种下层序列，这就表示可以获得拥有相同稳定属性的多种示踪剂分子。BaseTrace以此为基础开发了多种算法，可计算出哪些种类的序列最适合应对指定应用情况。这种示踪方法最近已经从石油行业拓展至核能行业，用于帮助应对其最严峻的问题：废水处理。

• Algorithm：n. 算法

Another approach to protecting tracer DNA is encapsulation. Well Genetics, a Norwegian firm, wraps the molecules in polymer coatings. The company has been testing these tiny capsules, in collaboration with oil- and gas-production companies drilling in a North Sea oilfield and in a shale-gas field in Texas. Tracesa, a British company, is also developing polymer-coated DNA. And Haelixa, a firm spun out from the Swiss Federal Institute of Technology, in Zurich, is encapsulating DNA using a different material: glass.

另一种保护示踪DNA的方法是增加包覆层。挪威公司Well Genetics选择使用高分子涂层包覆DNA分子，他们已经与一些在北海油田和德克萨斯州页岩气田进行钻探作业的石油与天然气生产企业合作，对这些小小的DNA“胶囊”进行测试。一家英国公司Tracesa，也在开发用来包覆DNA的聚合物。而原苏黎世联邦理工学院下属公司Haelixa则选择使用另一种包裹材料——玻璃。

• Encapsulation n. 封装；包装

• Polymer coating 聚合物涂层；高分子涂层

• in collaboration with：与……勾结；与……合作

• oilfield：n. 油田

Haelixa is not, however, always aiming for perfect protection. The company’s researchers have shown that the amount of damage DNA undergoes, if held in glass particles that have had holes etched in them, is a precise measure of the temperature that those particles have encountered in their underground journey. They have also gone on to show that such particles can measure acidity, too.

不过，Haelixa的目标并非完全追求绝对的保护。公司的研究人员已经证实，利用蚀刻技术在玻璃颗粒上钻孔并放入DNA分子后， 受损DNA的数量有所下降，而利用这种方法可以精确地测量示踪DNA途经的地底温度。此外，研究人员正在研究如何利用此类颗粒测量酸度。

• Etch vt. 蚀刻；鲜明地描述；铭记

• Acidity n. 酸度；酸性

These results have caused interest in the oil and gas industries, which currently lack means of taking readings of this sort beyond the limits of their boreholes, and among geothermal-energy types, the success of whose ventures depends on exploiting the varying temperatures at a given site.（读者试译句） Last month, in partnership with Clariant Oil Services, another Swiss firm, Haelixa started testing its technology in an American oilfield.

（期待您的翻译，明天会有针对这句话的长难句解析哟~）。上个月，Haelixa 与另一家瑞士公司Clariant Oil Services展开合作，在美国的一处油田开始测试其新示踪技术。

Haelixa’s inventive approach—turning tracers into sensors—opens a new avenue of research. Mapping what is going on underground has always been hard. Yet underground is where most natural resources lie. A better understanding of the subterranean will help those resources to be extracted more cheaply and cleanly.

Haelixa别出心裁地化示踪剂为传感器，这为示踪技术研究开辟了一条新路。一般来说，想要清晰描绘地底情况是非常困难的，而地底又是自然资源储量最丰富的地方。所以，如果能够更好地了解地下的情况，就有助于以更经济、更清洁的方式开采这些资源。

• Inventive adj. 发明的；有发明才能的；独出心裁的

翻译 ▍陌生

审核 ▍妖精

编辑 ▍且听风吟