石油专业知识

1、1Chapter 2 Petroleum Geology and Reservoirs(石油地質及儲油層)2009References石油地質及儲油層 (Petroleum Geology and Reservoir)Textbook 1 Fundamentals of Petroleum, Petroleum Extension Service, The University of Texas at Austin, Austin, Texas,1979. chapter 1Textbook 2 Archer, J. S., and Wall, C.G., Petroleum Engineer

2、ingprinciples and practice, Graham & Trotman, MD, 1986. chapter 2TextBook 3 Donohue, D.A.T., and Lang K.R., A First Course in Petroleum Technology, International Human Resources Development Corporation, Houston,1986 chapter 4.1; 4.223Petroleum Geology (石油地質)Geology (地質) -研究(1)地球的歷史及構造 (2)記錄在岩石的生物(命)

3、形式Petroleum Geology(石油地質) -研究地質以預測石油累積之處所4地球的形成及構造 地球的形成 4050億年前由宇宙塵(Cosmic dust)的凝結而成地球內部大構造 Core- heavy (4,400 miles) Mantle- Lighter (1,800 miles) Crust- 1030 miles5地球內部大構造Core- heavy (4,400 miles)Mantle- Lighter (1,800 miles)Crust- 1030 miles在地球上，不管您走到哪裡，你都是在岩石（Rock）的上面。在加州的某些地方，你是站有岩石的上面20哩處20哩

4、是多少?6MILES = 9.6 KILOMETERS20MILES = 32 KILOMETERS喜馬拉雅山大約有6哩高所以20哩是喜馬拉雅山的3倍高，其間有很多的岩石。7地球表面的變化 - Rock cycleMagma(岩漿)Igneous rocks(火成岩)Sediments(沉積物)SedimentaryrocksMetamorphicrocks地球內部Water vapor and gasesPrimeval(初期的)Atmosphere(大氣)地殼冷卻地殼收縮變形而皺摺噴出形成heatheatpressureerosionerosionpressurecementationer

5、osion下雨Cool8沉積岩的分類 ClasticChemicalOrganicOtherConglomerateSandsonteSiltstoneShaleCarbonateEvaporitePeatCoalDiatomiteLimestoneChertLimestoneDolomiteGypsumAnhydriteSaltPotash碎屑岩化學岩有機岩其他礫岩砂岩粉砂岩頁岩碳酸鹽蒸發岩泥炭煤矽藻土石灰岩角岩石灰岩白雲石石膏硬石膏鹽岩碳酸鉀(鉀化合物)9Reservoir Rock (Sedimentary Rock)Reservoir RockProrsityPermeabilityS

6、andstones (SiO2)CarbonatesLimestones (CaCO3)Dolomites (CaCO3, MgCO3)10地球的歷史寒武紀(Cambrian)【約5.5億年前】開始在海洋裡有大量的生物(生命) 在寒武紀之前為前寒武紀(Precambrian)地質年代自寒武紀開始 地質代年表(Geologic Time Scale)泥盆紀(Devonian)時期【約3.3億年前】陸上有大量植物及動物11Geological Time Scale12地層年代表 1314Petroleum accumulation(石油累積)Petroleum reservoir(石油油藏;油藏;

7、油層)Petroleum accumulation必須具備 (1)Oil gas 之來源 (2)具有孔隙(porosity)及滲透率(permeability)之Reservoir Rock (3) 要有trap(封閉)以阻擋流體的流動15石油的來源16石油的來源石油來自沈積岩的有機物質海洋裡大量的生物不停的，緩慢的掉落到海底。 雖然在掉落的過程中，有部分被吃掉或被氧化掉， 但另部份(動物或植物)掉落海底而埋在沼澤或泥濘之 海底海底繼續被Sand(砂)，Clay(黏土)及debris等沈積物埋沒 一直到幾千英呎沈積物的壓力開始作用。 細菌由殘餘的有機物質中，用掉氧而分解物質， 使其僅存碳及氫在

8、高度的壓力及重量的地層影響之下， Clays變成Shales 石油產生砂、淤泥及泥土的顆粒沉到水裡，蓋在死的矽藻類以及其他的動植物之上。而且，水被夾在這些砂、淤泥及泥土的顆粒之中。不久，這些顆粒，又被其他的動植物殘骸覆蓋。這個過程，一再的重複，最後，泥、砂及水累積達幾千呎厚。這些砂、泥在堆積過程中，底部的砂、泥受到上部砂、泥而擠壓在河流、湖及海底的泥、砂、水及動植物殘骸所受的覆蓋壓力逐漸的變大當覆蓋深度加大而變深，其溫度也增加。經過幾百萬年之後，在適當的壓力及溫度之下，這些泥砂顆粒就變硬而成為岩石，類似褐色或灰色的水泥。當動植物的殘骸腐朽之後，形成石油及天然氣，大部分的石油及天然氣係由相當微小

9、的動植物殘骸而來的確實的石油及天然氣之形成原因仍不清楚。但是，溫度、壓力及細菌是很重要的因素。18 Petroleum formation requires that organic source clays become mature by subjection to pressure and temperature. 19石油形成的重要條件225 temperature 350 有利條件 temperature 500 有機物質碳化， 不能形成石油20Generation of gas and oil2122In geology and oceanography, diagenesis i

10、s any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration (weathering) and metamorphism. 23Catagenesis can refer to:Catagenesis (geology) The cracking process in which organic kerogens a

11、re broken down into hydrocarbons; Catagenesis (biology) Retrogressive evolution, as contrasted with anagenesis. 24Metamorphism can be defined as the solid state recrystallisation of pre-existing rocks due to changes in heat and/or pressure and/or introduction of fluids i.e without melting. There wil

12、l be mineralogical, chemical and crystallographic changes 25 Prolonged exposure to high temperatures, or shorter exposure to very high temperatures, may lead progressively to the generation of hydrocarbon mixtures characterized as condensates, wet gases and gas.The average organic content of potenti

13、al source rocks is about 1% by weight. The Kimmeridge clay, the principal source rock for North Sea oil average about 5% carbon (7% organic mater) with local rich streaks greater than 40%. The hydrogen content of the organic matter should be greater than 7% by weight for potential as an oil source.2

14、6 It is a rule of thumb that for each percentage point of organic carbon in mature source rocks, some 13001500 cubic meters of oil per km2-m (or 1040 barrels of oil per acre-ft; or 56-225 ft3/ 43560 ft3) of sediment could be generated. (1.31.5 m3oil: 1,000 m3 rock) It is not, however, necessarily tr

15、ue that all the oil generated will be expelled or trapped in porous rock.27石油移棲石油形成( in source rock)TrapsReservoir RocksMigration經過porous bed 有permeability由於Compaction of Source bed and .The migration process involves two main stages, namely from the source rock and then through a permeable system.2

16、8Migration of petroleum - from the source rock 29Migration of petroleum - from the source rock * Capillary effect * Microfractures Since the generation of petroleum is accompanied by volume changes which can lead to high local pressures, there may well be an initiation of microfractures which provid

17、e an escape route into permeable systems such as sedimentary rocks or fault planes. The source rock microfractures are believed to heal as pressures are dissipated.30Migration of petroleum -through a permeable system* Fluid potential gradient or gravity effect In the permeable system the transport o

18、ccurs under conditions of a fluid potential gradient which may take the hydrocarbon to surface or to some place where it becomes trapped. It might be assumed that less than 10% of petroleum generated in source rocks is both expelled and trapped, as shown in the example of Fig. 2.5. 3132Petroleum tra

19、ps(石油封閉)The characteristic forms of petroleum trap are known as structural traps(構造封閉) and stratigraphic traps(地層封閉), with the great majority of known accumulation being in the former style.33地質構造（Geological Structures）Erosion SedimentationUplift wearing downUpper crustmovementUpwarddownwardFaultNor

20、malReverseThrustLateralStrata or bedUnconformitydisconformityAngular unconformityFoldsArches (or upfold) anticlinesTraughs (or downfold) synclinesImportant to petroleum accumulation34Figure 1.12. Two general kinds of unconformities are disconformity (A) and angular unconformities (B) and (C).造山運動之應力

21、所造成沉積過程所造成Figure 1.13. Basic hydrocarbon reservoirs are structural and / or stratigraphic traps. 35封閉(traps)封閉(traps)Structural trapsan arched upper surfaceStratigraphic traps-up-dip termination of porosity (permeability)Structural trapsAnticline trapFault trapDome and plug trapStratigraphic trapsUn

22、conformity trapsLenticular trapDisconformityAngular unconformityCombination traps 36Cap rock and fluid distribution Impermeable rocks provide seal above and below the permeable reservoir rocks.At equilibrium conditions, the density differences between the oil, gas and water phases can result in boun

23、dary regions between them known as fluid contacts, i.e. gas-oil and oil-water contacts.37Structural trap (構造封閉) - AnticlineLongitudinal view of a typical anticline. The oil cannot escape upward because of the impervious shale bed above the oil sand; neither can it travel downward because of the wate

24、r that is associated with an accumulation of this type.AnticlinesOf the many types of structural features present in the upper layers of the earths crust that can trap oil, the most important is the anticlinesthe type of structure from which the greater part of the words oil has been produced. Antic

25、lines are upfolds of beds in the earths crust, and, when the proper conditions are present, oil accumulates within the closure of there folds. 38Structural trap- Anticline Lateral, or end view, of a typical anticline.Plan view of a typical anticline, showing locations of longitudinal view A-B and la

26、teral view C-D.39Structural trapsFigure 1.7. Schematic cross section shows deformation of earths crust by bucking of layers into foldsFigure 1.8. Simple kinds of folds are symmetrical anticline (A), plunging asymmetrical anticline (B), plunging syncline (C), and dome with deep salt core (D).Figure 1

27、.9. Simplified diagram of the Milano, Texas, fault.40Structural traps dome & anticlineFigure 1.15. Oil accumulates in a dome-shaped structure (A) and an anticlinal type of fold structure (B). An anticline is generally long and narrow while the dome is circular in outline. (Courtesy of American Petro

28、leum Institute)4142Structural traps - faultsFigure 1.10. Simple kinds of faults are normal (A), reverse (B), thrust (C), and lateral (D).Figure 1.11. Variations of normal and reverse faulting are rotational faults (A) and upthrust faults (B).43Structural trapsFigure 1.14. Common types of structural

29、traps44Structural trap fault & anticlineFigure 1.17. Shown in map view, fault traps may be simple (A) or compound (B).Figure 1.16. Gas and oil are trapped in a fault trap-a reservoir resulting from normal faulting or offsetting of strata. The block on the right has moved up from the block on the lef

30、t, moving impervious shawl opposite the hydrocarbon-bearing formation. (Courtesy of American Petroleum Institute)45Stratigraphic traps(地層封閉)46Figure 1.12. Two general kinds of unconformities are disconformity (A) and angular unconformities (B) and (C).造山運動之應力所造成沉積過程所造成Figure 1.13. Basic hydrocarbon

31、reservoirs are structural and / or stratigraphic traps. 47Stratigraphic trapsUnconformity Disconformity Angnlar unconformity PinctoutSand lensesChanges in sedimentation48Figure 1.22. Oil is trapped under an unconformity. (Courtesy of API)Figure 1.23. Lenticular traps confine oil in porous parts of t

32、he rock. (Courtesy of API)49Stratigraphic trapAn example of a stratigraphic trap where the oil zone pinches out.A stratigraphic trap where sand lenses are interspersed in a shale bed. The shale acts as a permeability barrier50Stratigraphic TrapsA stratigraphic trap where changes in sedimentation act

33、 as a permeability barrier.An angular unconformity as an oil trap. The flat-lying shale bed above the oil zones acts as a permeability barrier. 51Stratigraphic trapsStratigraphic traps result when a depositional bed changes from permeable rock into fine-grain impermeable rock (Fig. 2.8).5253Combinat

34、ion trapsMany reservoirs exist as the result of a combination of structural and stratigraphic features. In the Viking Graben area of the northern North Sea, the Brent Sand reservoirs are characteristically faulted deltaic sands truncated by the Cretaceous unconformity.5455Reservoirs Reservoir(儲油層)We

35、 may define a reservoir as an accumulation of hydrocarbon in porous permeable sedimentary rock.The accumulation, which will have reached a fluid pressure equilibrium throughout its pore volume at the time of discovery, is also sometimes known as a pool.A hydrocarbon field may comprise several reserv

36、oirs at different stratigraphic horizons or in different pressure regimes. 5657 Field An area consisting of a single reservoir or multiple reservoirs all grouped on, or related to, the same individual geological structural feature and/or stratigraphic condition. There may be two or more reservoirs i

37、n a field that are separated vertically by intervening impermeable rock, laterally by local geologic barriers, or both. The term may be defined differently by individual regulatory authorities.58Reservoir(儲油層) A subsurface rock formation containing an individual and separate natural accumulation of

38、moveable petroleum that is confined by impermeable rocks/formations and is characterized by a single-pressure system.59Reservoir(儲油層) 具有商業價值的石油(及天然氣)地層-reservoir，所需具備之條件 (1)合適之地層形貌 (Shape/Configuration- traps) (2)頂蓋層 (cap rock, rock seal) (3)儲油層之面積(area)大 (4)儲油層之厚度(thickness)大 (5)儲油層之孔隙率(porosity)大

39、(6)儲油層之含水飽和度(water saturation)小 (7)儲油層之滲透率(permeability)大60原油現地藏量Original oil in place (OOIP) OOIP = A * h * * (1-Sw)* 1/Bowhere A=儲油層之面積(area) h=儲油層之厚度(thickness) =儲油層之孔隙率(porosity) Sw =儲油層之含水飽和度(water saturation) Bo = 石油地層體積因子(oil formation volume factor)61原油現地藏量Original oil in place (OOIP) OOIP =

40、 7758* A * h * * (1-Sw)* 1/Bowhere OOIP = 原油現地藏量, STB A=儲油層之面積(area), acres h=儲油層之厚度(thickness), ft =儲油層之孔隙率(porosity), fraction Sw =儲油層之含水飽和度(water saturation), fraction Bo =石油地層體積因子(oil formation volume factor) , bbl/STB1 acres = 43560 ft21 bbl = 5.61458 ft362資源量及蘊藏量定義資源量 (Petroleum Resources， 或 R

41、esources， 或 Total Petroleum in place ， 或 Original oil in place ) 在一區域或礦區所存在的石油（含天然氣）之總量，稱為資源量。蘊藏量(Petroleum Reserves，或 Reserves ) 在一已知區域或礦區中，自某一時間點開始，依據當時的經濟條件(E)、工程技術(F)、及地質條件(G)下，在可預見的未來所能採收的石油（含天然氣）之量稱為蘊藏量，或最終採收量。ResourcesThe term “resources” as used herein is intended to encompass all quantities

42、 of petroleum (recoverable and unrecoverable) naturally occurring on or within the Earths crust, discovered and undiscovered, plus those quantities already produced. Further, it includes all types of petroleum whether currently considered “conventional” or “unconventional” (see Total Petroleum Initi

43、ally-in-Place). (In basin potential studies, it may be referred to as Total Resource Base or Hydrocarbon Endowment.)63Total Petroleum Initially-in-Place Petroleum Initially-in-Place is the total quantity of petroleum that is estimated to exist originally in naturally occurring reservoirs. Crude Oil-

44、in-place, Natural Gas-in-place and Natural Bitumen-in-place are defined in the same manner (see Resources). (Also referred as Total Resource Base or Hydrocarbon Endowment.)64Reserves65Reserves are those quantities of petroleum anticipated to be commercially recoverable by application of development

45、projects to known accumulations from a given date forward under defined conditions. Reserves must further satisfy four criteria: They must be discovered, recoverable, commercial, and remaining (as of a given date) based on the development project(s) applied.666768Reserves (蘊藏量) Reserves = OOIP * rec

46、overy factorwhere OOIP = A * h * * (1-Sw) * 1/Bo recovery factor (採收因子) = f( k, E, P, T ) k = permeability (滲透率)69 The setting for hydrocarbon accumulation is a sedimentary basin that has provided the essential components for petroleum reservoir occurrence, namely(a) a source for hydrocarbons, (b) t

47、he formation and migration of petroleum,(c) a trapping mechanism, i.e., the existence of traps in porous sedimentary rock at the time of migration and in the migration path.The discovery of oil by exploration well drilling in some of the worlds sedimentary basin is shown in Figs. 2.1 and 2.270Explor

48、ation Showing a Good Success Rate23 March 2006 - A strong reflection of New Zealands prospectivity for oil and gas has been shown by the substantial lift in exploration wells drilled since 2000, and particularly in the past two years. A strong reflection of New Zealands prospectivity for oil and gas

49、 has been shown by the substantial lift in exploration wells drilled since 2000, and particularly in the past two years.In his keynote presentation to the New Zealand Petroleum Conference, which had a record attendance of more than 520 of which many were from overseas, Associate Energy Minister Harr

50、y Duynhoven said a total of 149 wells were drilled in the past six years, of which 74 were wildcats.In the past 24 months 69 wells were drilled. The Minister said that of the total 74 wildcats there were 12 discoveries, indicating a success rate of about 16%.Exploration Success Rate71現今的石油鑽井很安全；很多國家

51、都有制定法令以保護地表及地下之自然環境。在七個探勘井中會有一口具有生產利潤的生產井對於不具生產價值的井，必須用水泥及泥土將井口封閉起來72104 m3 oil / wildcat 108 m3 oil / wildcat 106 m3 oil / wildcat 73Lower right line (0.1 103 m3 oil / km2 ) / (100 willcat wells/104 km2 ) = 104 m3 oil / willcat well = 6.289*104 bbl3 oil / willcat wellUpper left line (10 103 m3 oil

52、/ km2 ) / (1 wildcat well/104 km2 ) = 108 m3 oil / wildcat well = 6.289*108 bbl oil / wildcat well104 m3 oil / wildcat 108 m3 oil / wildcat 106 m3 oil / wildcat 74100% successful wildcat / wildcat1% successful wildcat / wildcat75Lower right line (0.01 106 m3 oil discovered / willcat ) / (1 106 m3 oi

53、l discovered/ successful wildcat ) = 1% successful wildcat / wildcatUpper left line (0.1 106 m3 oil discovered / wildcat ) / (0.1 106 m3 oil discovered/ successful wildcat ) = 100% successful wildcat / wildcat100% successful wildcat / wildcat1% successful wildcat / wildcat7677Reservoir fluids and pr

54、essure From a petroleum engineering perspective it is convenient to think of sedimentary basins as accumulations water in areas slow subsidence into which sediments have been transported.79Reservoir fluids and pressureReservoir fluidsGasOilwaterWater connate water(connate interstitial water)Free waterAquiferBottom waterEdge waterGasSolution gas Free gas80Fluid p