http://www.financialsensearchive.com/fsu/editorials/2010/0603.html !"# Energy is the power to drive forwards the industrialization and modernization of the society.The development and utilization of energy governs the competitive strength and comprehensivenational power of a country.Oil & Gas is an important kind of energy, high!uality material for chemical industry, and animportant warfare material. "ecause it is important to #oth the energy safety and national defenseof a country, great attentions have #een paid to petroleum industry and oil & gas trade #y all of thecountries. $t is hard to imagine what the society would #e without the oil and gas today. $t can #esay that petroleum plays an important and indispensa#le role in the economic development of theworld. $n the past %& years since the #irth of 'eople (epu#lic of )hina, our petroleum industry hasgrowth rapidly. The annual oil production was only *+,&&& tons in year ,+-+. The annual oilproduction increase up to ,.& million tons in /&&., and ranks within the top - countries in theworld. On the other hand, the consumption of oil and gas also increase greatly with the societyand economy development in our country. 0ince ,++. )hina had #ecome one of the #igestpetroleum consuming countries in the world. $%&'()*+alkanecyclane arene Chapter 1 Chemical Composition andProperties of Reservoir Fluids Chapter 1 Chemical Composition andProperties of Reservoir Fluidsection Ph!sico.chemical Properties of Reservoir Fluids Chapter 1 Chemical Composition and Properties of Reservoir Fluids1.1 Chemical Properties of Crude "il1.2 Ph!sical Properties and Classification of Crude "il1.3 Chemical Composition of #atural $as1.% Classification of "il&$as Reservoirs1.' (he Chemical Composition and Classification of Formation water "y analysing oil1s elemental composition,it is cocomprised predominatly of car#on and hydrogen elements and also contains a small !uantity of sulfur,o2ygen,nitrogen,as well as some others like trace elements.1.(he elemental of composition of "il 1.1.1(he elemental of composition of "ilThe percentages of the car#onand hydrogen contents in crude oil are listed in Ta#le.crude oil consists of appro2imately *345*.4 car#on and ,,45,-4hydrogen ,and the sum of )67 is up to+845++4 #y weight.9or some oil from oil fields in )hina,The hydrogentocar#on molar ratio tends comparatively high. ,.,./ the hydrocar#ons compounds in crude oilThe alkane in crude oil1 )n the oil with linear or *ranched chain+ *ut no rin, structure of saturated h!drocar*on+ called the al-ane."*viousl!+al-ine is saturated h!drocar*ons..l-anes are chemicall! inactive and inert to react with othe materials unless the! are su*/ected to the conditions of heatin,+ catal!st or photochemical action+in which the! can en,a,e )n -inds of reactions such as halo,enation +sulfonation+o0idation+crac-in,+etc. (he c!clane in crude oil2al-ane is a rin, of saturated h!drocar*on+ its nature is sta*le+ and is the main component of oil. "r,anic chemist once for the s!nthesis of various car*on num*er of c!cloparaffin. 1ut+ in the oil in the e0istence of a lar,e num*er of onl! contain five car*on rin, c!clopentane s!stem and si0 car*on rin, c!clohe0ane s!stem. #ature is sta*le2 (here are man! five car*on rin, and si0 car*on rin,. 3.(he non3h!drocar*on compounds in crude oilOxygen containing chemicals:naphthenic acid,etc.sulfocompound :itrogenous )ompounds colloid molecular wei,htof crude oil,(he least of the crude oil molecules 4m l5+-/ l ;are molecular wei,ht for 16 methane molecules is the lar,est asphalt+ its molecular wei,ht can amount to several thousand so crude oil molecular wei,ht ran,e is ver! lar,e+ a*out several hundred to several thousand. 1.2 Ph!sical Properties and Classification of Crude "ilThe main content of this section?ccording to the sulfur content,oil can #e classed and named as=/> ?ccording to thecolloid content,oil can #e classed and named as=3> ?ccording to wa2 content,oil can #e classed and named as=->?ccording to the key components oil can #e classed and named as 3.The classification of (esevior Oil-. m!a"s #5 5$2% 2%$5% &5%)7 /- - - 8'y Viscosity 1.3 Chemical composition of natural gas.:atural gas is mi2ture of gaseous hydrocar#ons of alkanes.$t is composed primarily of me thane with varing amount of ethane ,propane,and #utanes.@sually,nature gas consist of .&45+*4methane ,less than ,&4 ethane ,and small amounts of heavier gaseous hydrocar#on sompouns such as propane,#utane,pentane ,and so on. :ormally,the oil and gas reservoirs are classified and named $n the following methods?ccording to the geological features of reservoirsA=/>?ccording to the charateristics and distri#ution of the reservoir fluidsA=3> ?ccordingto the reservoir natural drive energy and types.1.% Classification of "il&$as Reservoirs 1.%.1 Classification 1oil and ,as reservoir "il reservoir $as reservoir1lac- oil ;i,ht oil$as3condensate,as