Petroleum Resources 石油資源

　　1.Petroleum, consisting of crude oil and natural gas, seems to originate from organic matter in marine sediment. Microscopic organisms settle to the seafloor and accumulate in marine mud. The organic matter may partially decompose, using up the dissolved oxygen in the sediment. As soon as the oxygen is gone, decay stops and the remaining organic matter is preserved.

　　段落梗概：石油和天然氣都是來自海底的有機(jī)物沉淀。部分有機(jī)物分解，部分沉積。

　　2.Continued sedimentation—the process of deposits’ settling on the sea bottom—buries the organic matter and subjects it to higher temperatures and pressures, which convert the organic matter to oil and gas. As muddy sediments are pressed together, the gas and small droplets of oil may be squeezed out of the mud and may move into sandy layers nearby. Over long periods of time (millions of years), accumulations of gas and oil can collect in the sandy layers. Both oil and gas are less dense than water, so they generally tend to rise upward through water-saturated rock and sediment.

　　段落梗概：持續(xù)的沉積——堆積物沉積到海底的過程將有機(jī)物埋在海底使之受到海底溫度、高壓的影響，最終轉(zhuǎn)變成石油和天然氣。當(dāng)泥狀沉積物被擠壓在一起時(shí)，天然氣和石油液滴會(huì)被擠出泥層，然后進(jìn)入附近的沙層。經(jīng)過很長的一個(gè)周期(數(shù)百萬年)，積聚的天然氣和石油會(huì)在沙層中聚集。

　　3.Oil pools are valuable underground accumulations of oil, and oil fields are regions underlain by one or more oil pools. When an oil pool or field has been discovered, wells are drilled into the ground. Permanent towers, called derricks, used to be built to handle the long sections of drilling pipe. Now portable drilling machines are set up and are then dismantled and removed. When the well reaches a pool, oil usually rises up the well because of its density difference with water beneath it or because of the pressure of expanding gas trapped above it. Although this rise of oil is almost always carefully controlled today, spouts of oil, or gushers, were common in the past. Gas pressure gradually dies out, and oil is pumped from the well. Water or steam may be pumped down adjacent wells to help push the oil out. At a refinery, the crude oil from underground is separated into natural gas, gasoline, kerosene, and various oils. Petrochemicals such as dyes, fertilizer, and plastic are also manufactured from the petroleum.

　　段落梗概：關(guān)于石油開采的一些介紹：包括油床、油田、井架概念的介紹;石油開采中的技術(shù)控制;以及地下的原油分離;石油用途等等。

　　4. As oil becomes increasingly difficult to find, the search for it is extended into more-hostile environments. The development of the oil field on the North Slope of Alaska and the construction of the Alaska pipeline are examples of the great expense and difficulty involved in new oil discoveries. Offshore drilling platforms extend the search for oil to the ocean’s continental shelves—those gently sloping submarine regions at the edges of the continents. More than one-quarter of the world’s oil and almost one-fifth of the world’s natural gas come from offshore, even though offshore drilling is six to seven times more expensive than drilling on land. A significant part of this oil and gas comes from under the North Sea between Great Britain and Norway.

　　段落梗概：石油越來越難以找到，石油勘探已經(jīng)開始到更惡劣的環(huán)境中進(jìn)行。舉了一個(gè)例子：阿拉斯加北坡油田的開發(fā)和阿拉斯加管道建設(shè)就是成本高、難度大的例子。

　　5. Of course, there is far more oil underground than can be recovered. It may be in a pool too small or too far from a potential market to justify the expense of drilling. Some oil lies under regions where drilling is forbidden, such as national parks or other public lands. Even given the best extraction techniques, only about 30 to 40 percent of the oil in a given pool can be brought to the surface. The rest is far too difficult to extract and has to remain underground.

　　段落梗概：地下還能發(fā)現(xiàn)更多的石油。許多石油資源都是由于開采費(fèi)用高、地理位置不能開采等原因不得不留在地下。

　　6.Moreover, getting petroleum out of the ground and from under the sea and to the consumer can create environmental problems anywhere along the line. Pipelines carrying oil can be broken by faults or landslides, causing serious oil spills. Spillage from huge oil-carrying cargo ships, called tankers, involved in collisions or accidental groundings (such as the one off Alaska in 1989) can create oil slicks at sea. Offshore platforms may also lose oil, creating oil slicks that drift ashore and foul the beaches, harming the environment. Sometimes, the ground at an oil field may subside as oil is removed. The Wilmington field near Long Beach, California, has subsided nine meters in 50 years;protective barriers have had to be built to prevent seawater from flooding the area. Finally, the refining and burning of petroleum and its products can cause air pollution. Advancing technology and strict laws, however, are helping control some of these adverse environmental effects.

　　段落梗概：從地下和海底開采石油并運(yùn)送到消費(fèi)者的途中的任何地方都會(huì)產(chǎn)生環(huán)境問題。石油運(yùn)輸管道損壞造成嚴(yán)重的石油泄漏，會(huì)導(dǎo)致海上產(chǎn)生浮油。海上鉆井平臺(tái)也可能會(huì)泄露石油，導(dǎo)致海灘污染，危害環(huán)境。有時(shí)油田石油被抽取后，地面會(huì)下沉。舉例。石油煉制、燃燒也會(huì)造成空氣污染。先進(jìn)的技術(shù)和嚴(yán)格的法律正在控制這些對(duì)環(huán)境的不利影響。

　　疑難詞：

　　petroleum n. 石油

　　marine adj. 船舶的;航海的，海運(yùn)的

　　sediment n. 沉積;沉淀物

　　decompose vt. 分解;腐爛vi. 分解;使腐爛

　　convert vi. 轉(zhuǎn)變，變換

　　droplet n. 小滴，微滴

　　squeeze n. 壓榨;緊握v. 擠;緊握;勒索

　　saturate adj. 浸透的，飽和的

　　drill vt. 鉆孔;訓(xùn)練;條播vi. 鉆孔

　　portable adj. 手提的，便攜式的

　　dismantle vt. 拆除;取消vi. 可拆卸

　　collision n. 碰撞;沖突

　　ashore adj. 在岸上的;在陸上的adv. 在岸上

　　adverse adj. 不利的;相反的