How does fracking work? - Mia Nacamulli

譯者: Regina Chu 審譯者: Marssi Draw

Deep underground lies stores of once inaccessible natural gas.

地下深處埋藏著 原本無法開採的天然氣

This gas was likely formed over millions of years

這層油氣在數百萬年間

as layers of decaying organisms were exposed to intense heat and pressure

由層層堆疊的腐爛生物

在地殼下受高熱及壓力而形成

under the Earth's crust.

There's a technology called hydraulic fracturing,

現在有一種技術稱為水力裂解

or fracking,

又稱壓裂

that can extract this natural gas,

可以開採這種天然氣

potentially powering us for decades to come.

在未來數十年繼續提供能源

So how does fracking work,

壓裂的方法為何？

and why it is a source of such heated controversy?

為什麼這種方法 產生如此激烈的爭議？

A fracking site can be anywhere with natural gas,

只要有天然氣的地方 都可以用壓裂開採

from a remote desert

無論是在偏遠的沙漠

to several hundred feet from your backyard.

還是在後院咫尺都可以

It starts out with a long vertical hole known as a wellbore

首先，要打一口垂直井管

drilled down through layers of sediment.

穿過層層的沉積物

When the well reaches 2500 - 3000 meters, it's at its kickoff point

在深及 2.5 至 3 公里處 達到側出點時

where it can begin the process of horizontal drilling.

就開始水平鑽井

It turns 90 degrees and extends horizontally for about 1.5 kilometers

它會 90 度大轉彎 並橫向伸展約 1.5 公里

through a compressed black layer called the shale rock formation.

穿過緊密的黑色頁岩層

A specialized perforating gun is then lowered and fired,

然後把特別打造的穿孔槍 送近井底並轟擊

creating a series of small, inch-long holes

產生一系列約一吋長的小洞

that burst through the well's casing into the rock layer.

穿透護井套管進入岩層

About three to four months after the initial drilling,

開始鑽井後三到四個月內

the well is ready for fracking to begin.

油井就預備好可以開始壓裂

Fracking fluid is pumped down into the well at a pressure so high,

壓裂液體被泵以高壓送進井內

it cracks the shale rock,

壓力如此之高，造成頁岩碎裂

creating fractures through which the trapped gas and oil can escape.

產生裂縫

讓其中的油氣及石油跑出來

The fluid itself is more than 90% water.

壓裂液本身 90% 以上是水

The rest is made up of concentrated chemical additives.

其餘則由濃縮的化學添加物組成

These vary depending on the specific characteristics of the fracking site,

要用哪些化學物 取決於壓裂地點的特性

but usually fall into three categories:

但通常分為三類：

acids for clearing debris and dissolving minerals,

清除碎屑及溶解礦物質的酸類

friction-reducing compounds to create

減少摩擦力的化合物

a slippery form of water known as slickwater,

使水變成潤滑劑

and disinfectant to prevent bacteria growth.

及避免細菌成長的防腐消毒劑

Sand or clay is also mixed into the water to prop open the fissures

細砂或黏土也會混進水中來撐開裂縫

so the gas and oil can keep leaking out, even after the pressure is released.

讓油氣及石油滲出 即使在洩壓狀態也會持續

It's estimated that all of fracking's intense pumping and flushing

據估計每口油井在壓裂時 所需要的高壓及沖水

uses an average of 3-6 million gallons of water per well.

平均要花掉三百到六百萬加侖的水

That's actually not a lot compared to agriculture,

與其它各業相比這其實不大

power plants,

如農業、發電廠

or even golf course maintenance,

甚至比維護高爾夫球場還少

but it can have a notable impact on local water supply.

但是它的確會對當地供水 產生很大的影響

And disposing of used fracking water is also an issue.

如何處理壓裂後的廢水也是問題

Along with the trapped gas that's pumped up to the surface,

抽到地表的除了儲存的油氣

millions of gallons of flow-back liquid come gushing up.

還有數百萬加侖的 回流液體也會湧上來

This liquid containing contaminants like radioactive material,

這種液體包含污染物，如放射線物質

salts,

鹽

heavy metals,

重金屬

and hydrocarbons,

及碳氫化合物

needs to be stored and disposed of.

這些都需要儲存並廢棄

That's usually done in pits on-site in deep wells

通常是在現場深井坑中處理

or off-site at water treatment facilities.

或在場外的廢水處理廠做

Another option is to recycle the flow-back liquid,

另一種選擇是回收回流液體

but the recycling process can actually increase levels of contamination

但是回收過程其實會增加汙染程度

since the water is more toxic with each use.

因為水在每次使用後都變得更毒

Wells are typically encased in steel and cement

油井通常都用鋼及水泥包覆

to prevent contaminants from leaking into groundwater.

以避免汙染物外洩進入地下水

But any negligence or fracking-related accidents

但是任何人為疏忽 或與壓裂有關的意外

can have devastating effects.

都會造成災難

Fracturing directly into underground water

如果壓裂管直接進入地下水

hazardous underground seepage and leakage,

會有地下滲漏的風險

and inadequate treatment and disposal of highly-toxic waste water

而且不當處理及廢棄高毒性廢水

can potentially contaminate drinking water around a fracking site.

有可能污染壓裂場所附近的飲用水

There's also concern about the threat of earthquakes

另一項隱憂則是地震的威脅

and damaged infrastructure

及基礎建設受損

from pressure and waste water injection.

因為高壓及廢水注入

Links between fracking and increased seismic activity

壓裂與地震活動增加的關聯性

leave unresolved questions about long-term pressure imbalances

造成無法解決的長期壓力不平衡問題

that might be happening deep beneath our feet.

都可能在我們的腳下發生

Fracking's biggest controversy, though, is happening above the ground.

然而壓裂最大的爭議點 還是在地表之上

The general consensus is that burning natural gas is better for the environment

一般公認燃燒天然氣

比燃煤還要環保

than burning coal

since the gas collected from fracking

因為壓裂採集的氣體

emits only half the carbon dioxide as coal

每單位能量排放的二氧化碳 比燃煤還少一半

per unit of energy.

The pollution caused by the fracking itself, though,

然而壓裂本身產生的污染

isn't negligible.

卻無法忽略

Methane that leaks out during the drilling and pumping process

鑽井及抽油過程產生的外洩甲烷

is many times more potent than carbon dioxide

以溫室效應氣體而言 其毒性比二氧化碳還高出許多倍

as a greenhouse gas.

Some scientists argue that methane eventually dissipates,

有些科學家認為甲烷最終會發散

so has a relatively low long-term impact.

所以長期影響相對較低

But a greater question hangs in the air.

但是還有更大的問題懸而未決

Does fracking take time, money, and research

壓裂是否消耗時間、金錢與研究等

away from the development of cleaner renewable energy sources?

原本可放在發展 清潔再生能源的資源？

Natural gas is non-renewable,

天然氣為不可再生能源

and the short-run economic interests supporting fracking

而支持壓裂產生的短期經濟利益

may fall short in the face of global climate change.

可能在全球氣候變遷面前站不住腳

Experts are still examining fracking's overarching effects.

專家仍在探究壓裂的各種影響

Although modern fracking has been around since the 1940s,

雖然現代壓裂技術 早在 1940 年代就發展出來

it's boomed in the last few decades.

但是只在近幾十年才開始大量使用

As other sources of natural gas decrease, the costs of non-renewable energies rise,

因為其它天然氣來源變少 不可再生能源的費用提高

and cutting-edge technologies make it so accessible.

最先進的技術 也使得這個方法更容易使用

But many countries and regions have already banned fracking

但是許多國家及地區已經禁止壓裂

in response to environmental concerns.

因為其環保隱憂

It's undeniable that fracking has reshaped the energy landscape around the world,

不可否認，壓裂已經重塑 全世界的能源版圖

but for what long-term benefit and at what cost?

但是到底有什麼長遠的好處？ 又要付出什麼代價？