remaining high, prevents gas from evolving to form high gas saturation. Water production begins first in wells completed low on the structure because the water, in its displacing action on oil, arrives at these wells first. Water production in these wells increases continuously until the wells must be abandoned because oil production is insufficient to economically justify their continued operation. A much larger portion of oil originally in the reservoir is produced by energy and action of a water drive than by either dissolved gas drive or gas cap drive. Such recovery normally will be approximately 35 to 75 per cent of original oil in place. 56、The passage mainly focuses on （C） A. water in the rock B. water drive reservoir
C. an introduction of water drive D. the gas-oil ratio in a water drive reservoir 57、The word \ （C） A. plot B. study C. make visible D. see
58、Which of the following would best illustrate \ （B） A. Water could compact the rocks to squeeze the oil.
B. Water moves in the rocks to replace the oil as is produced because of expansion of the minutely compressed water.
C. Water could make rocks expand to replace the oil . D. The rocks could drive the water.
59、The word \ （D） A. indulged B. emited C. fired D. given up
60、Why does the gas-oil ratio remain about the same in a water drive reservoir? （B） A. Because the gas-oil ratio remains constant under any conditions.
B. Because pressure, remaining high, prevents gas from evolving to form a high gas saturation.
C. Because the producing rates of gas and oil are equal.
D. Because the gas saturation in oil is so low that the gas-oil ratio remain about the same.
PASSAGE THIRTEEN
Surface Treatment of Crude Oil
When the crude oil has been brought to surface, the next step is to reduce it to the form
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in which it will be sent to the refinery for processing. The oil as produced at the wellhead varies considerably from field to field, due not only to the physical characteristics, but also to the amount of gas and salt water which it contains. In some cases no salt water will flow into the well from the reservoir along with the oil; in these circumstances it is only necessary to separate the gas from the oil. When salt water is produced with the crude, it is essential to apply some form of water settling treatment before the oil is fit for dispatch to the refinery or the export point.
The oil from each producing well is conveyed from the wellhead to a ―gathering center‖ through a ―flow line‖. The gathering center, which is situated at some central point to handle the gas separation and also water separation if needed. There may be just one gathering center to a field or there may be several. The number required will depend on the number of wells and the distance between them, the shape and surface geography of the field, and the producing capacities of the wells. Sarir oilfield in Libya for instance had four gathering center to which were connected a total of some 40 production wells—covering a drainage area of about 150 square miles. After the crude oil has been processed it is transferred to the shipment terminal.
61、It is essential to apply some form of water settling treatment before the oil is _______ to the refinery or to the shipping point. （C） A. suitable to be sent out B. suitable to be used C. ready for shipment D. ready for refinery
62、Sarir oil field in Libya for instance had four gathering centers ______ a drainage area of about 150 square miles. （A）
A. occupying B. lying over C. protecting D. shutting 63、The crude oil _____ the wellhead. （B）
A. publishes from B. flows out from C. springs D. walks out of
64、The oil from each producing well is ______from the wellhead to a ―gathering center‖ through a ―flowline‖. （B） A. conveyed B. transferred C. promised D. compressed
65、Sarir oilfield in Libya for instance had ______ gathering centers to which were connected a total of some 40 production wells—covering a drainage area of about 150 square miles.（B） A. three B. two C. five D. four
PASSAGE FOURTEEN
Natural Sources of Energy Available to Produce Oil
What causes oil to flow from a reservoir? This was one of the first fundamental
questions that baffled men in the industry. Blowouts called ―gushers‖, obviously showed that great pressure existed in some oil reservoirs. In addition, it was recognized that, when pressure was high, oil was easily produced. When pressure dropped, however, some kind of
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pumping equipment was needed to help lift the oil to the surface from bottom of the well. Otherwise, reduced pressure in the reservoir was not sufficient to move the oil beyond some point within the well.
The energy available in nature to produce deposits had its origin in the same environment in which petroleum originated. Burial beneath hundreds or thousands of feet of sediments created pressure which compacted the rocks. If the pore channels are interconnected through all the sediments to the sea or the surface of the land, pressure existing within the fluids in the rock is the pressure exerted by the weight of that fluid and is independent of the weight of the rock. Pressure in the fluid within a given porous rock will normally be about 46 pounds per square inch per 100 feet of depth-the amount of pressure exerted by a column of salt water. Pressure in a reservoir 1,000—feet deep will then be about 460 pounds per square inch. Weight of the rock overburden is supported principally by the rock itself because less pressure occurs in the fluid than is required to support the rock overburden; however, at great depths porosity is thought to diminish because of great rock overburden pressures. This occurs even in rock which probably had high porosity while existing at shallower depths before earth movements displaced it to greater depths. 66、When pressure is ______, oil was easily produced. （B） A. low B. high C. thick D. thin
67、The energy available in nature to produce petroleum deposits originates in the __________ environment as petroleum does. （C） A. different B. similar C. same D. special
68、How many pounds is the pressure in the fluid within a given porous rock per square inch per 100 feet of depth? （D） A.460 B. 1000 C. 100 D. 46
69、Weight of rock overburden is supported _____ by the rock itself. （B） A. basically B. chiefly C. usually D. particularly
70、Rock porosity is not influenced ______ by rock overburden . （C） A. widely B. primarily C. greatly D. quickly
PASSAGE FIFTEEN
Types and Shapes of Reservoirs
Many proposals have been made to classify the different physical shapes of petroleum reservoirs that have been discovered; however, the simplest means of such classification is perhaps a grouping according to the geologic features causing their occurrence. These features are (1) structural folding, (2) structure with faulting, (3) structure with an unconformity, (4) structure caused by some deep-seated movement of earth materials, (5) changes in permeability within a formation and (6) combinations of two or more of the foregoing .
Reservoirs formed in folded strata usually result in domes or anticlines. These traps
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were filled by oil moving upward through permeable beds to a point where it was stopped by the impermeable beds on top of the reservoir strata. It is common to find traps partially filled with water where the structure is large enough to hold more oil or gas. Examples of reservoirs formed by anticlinal folding of the structure are the Pegasus fields, Midland and Upton Counties, Tex and the great Azmari Limestone fields of Iran.
Reservoirs formed by faulting occur where escape of oil is prevented by impermeable beds moving into position against the oil-bearing rock on the opposite side of the fault plane. The oil is held in traps of this type by the structural dip of the bed and the faulting. Reservoirs of this type are typified by the Mt. Poso field, Kern County, Calif and the Luling, Mexia and Talco fields, in Central Texas.
71、Many ____have been made to classify the different physical shapes of petroleum reservoirs. （A）
A. suggestions B. decisions C. expectations D. examinations 72、Generally, reservoirs have _______geological features. （A） A. four B. six C. two D. many
73、It is common to find traps _______filled with water. （B） A. partially B. entirely C. regularly D. usually 74、Upward escape of oil has been stopped by the impermeable material. This usually happens in _______. （C） A. reservoirs formed by faulting B. reservoirs formed in folded strata
C. reservoirs formed as a result of an unconformity
D. reservoirs closed by variation in permeability within the strata. 75、Azmari Limestone fields is in ______. （C）
A. Midland B. Iran C. Californla D.Texas
PASSAGE SIXTEEN
Sedimentary Rocks
Rocks formed from materials derived from pre—existing sources that are transported and deposited are called sedimentary rocks. They may result from the accumulation of particles weathered from rock exposures, transported and ultimately deposited, may accumulate by precipitation from solution, or may result from buildup formed from skeletons or life processes of marine animals and plants. Sedimentary rocks can be classified according to environment of deposition, rock type, or by origin.
Rocks classified according to environment will include those classified by rock type and origin. This means that an exclusive classification by environment is not realistic because it is not unique. Classifications by rock type and origin are useful only in the identification of a rock in absolute terms. Since sedimentary rocks come from many sources that can produce nearly
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identical lithologies a combination of classification criteria is often useful. An example of this is a marine near—shore sandstone versus a near — shore sandstone deposited in a lake. The sandstone in each case is a clastic rock. However, the composition of the sandstone grains in each is not determined and would need identification to complete the classification.
Many environments of deposition are possible in the formation of sedimentary rocks. They include: marine, swamp, lacustrine (lake), fluvial (river), eolian (wind), estuarine, glacial, and lagoonal among others. Combinations of these environments are possible, for example, where a desert lake and sand duncs may come together.
Since there are numerous types of sedimentary rocks, there can be many classifications based upon lithology. There are many types of limestone, a number of rock types include: limestone, feldspathic sandstone, sandy siltstone, etc. All of these rock types came from a particular environment of depositing that further identifies them.
76、In the first paragraph the word ―ultimately‖ means_____. （A） A. finally B. continuously C. at first D. at once 77、In the sentence ―This means …. not unique‖ The word ―exclusive ‖ means _______.（D） A. total B. alone C. private D. unique
78、There can be many classifications based upon _____. （A） A. lithology B. geology C. biology D. philology
79、______these rock types came from a particular environment of deposition. （D） A. A few B. A number C. Some of D. All of 80、The clastic particles are ______from the original rock. (B) A. used B. obtained C. weathered D. deposited
PASSAGE SEVENTEEN
Pipelines
Oil usually has to be transported great distances from the oilfield to where it is going to be used. There are two main methods of transporting the oil, by pipeline and by tanker. Water transport is usually much cheaper, and tankers are used wherever possible.
Pipelines are used to take the crude oil from the oilfield or to the seaports to refineries, and to take the refined oil from the refineries to where it is going to be used. It is very expensive to install pipelines across the desert, may cost as much as ￡ 80,000 per mile. But pipelines help to save money by saving talkers from having to make long sea voyages. For example, oil exported from Iraq to Europe used to be transported by tankers through the Gulf, the Arabian Sea, the Red Sea, and the Suez Canal , into the Mediterranean SeA. In 1934 a pipeline was installed from the Kirkuk oilfield in Iraq to the Lebanese port of Tripoli. In 1952 another pipeline from Kirkuk was installed, leading to the Syrian port of Banias. Tankers now have only short voyages from these Mediterranean ports to Europe.
The first oil pipeline was installed in 1865 in Penusylvania,USA. It carried crude oil
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