石油及天然气地质学.ppt

1、石油及天然气地质学Geology of Petroleum and Natural Gas,徐思煌 资源学院石油系,(English),2,Petroleum Geology,Petroleum Geology,By Dr Xu Sihuang,Petroleum Geology,By Dr. Xu Sihuang 40hours Lecturing 26hs +practice 8hs+ discussion 2hs+others 4hs Lecture in English,Lecture contents,Petroleum Geology,Part 1 Introduction,Par

2、t 2 Petroleum reservoirs and the fluids in it,Part 3 The formation of petroleum reservoir,Chapter 1,Chapter 2 Chapter 3 Chapter 4,Chapter 5 Chapter 6 Chapter 7,Contents,Part 1 Introduction Chapter 1 Preface Part 2 Petroleum Reservoirs and the fluids in it Chapter 2 The Fluids in Reservoir Section 1

3、The oil (petroleum) Section 2 The natural gas: Section 3 The oil-field waters Chapter 3 The reservoir rock and cap rock Section 1 General concepts Section 2 Physical properties of reservoir rock Section 3 The character of reservoir rock Section 4 The roof rock(cap rock) Chapter 4 The traps and reser

4、voir of oil and gas Section 1 Concepts and classification of trap and reservoir Section 2 Character of structural trap and reservoir Section 3 Character of stratigraphic trap and reservoir Section 4 Character of other trap and reservoir,Back,Part 3 The formation of petroleum reservoirs Chapter 5 The

5、 generation of oil and gas Section 1 The organic matter Section 2 Kerogen Section 3 Main trend during kerogen forming petroleum Section 4 Temperature, time, and pressure Chapter 6 Migration of oil and gas Section 1 Terms Section 2 Primary migration Section 3 Secondary migration Chapter 7 Accumulatio

6、n of oil and gas Section 1 General Section 2 Differential entrapment in series traps Section 3 Petroleum alteration,Back,Part 1 Introduction Chapter 1 Preface,How about petroleum industry? important or unimportant? How about petroleum production and reserve? rich or poor? much or less? How about thi

7、s course? difficult or easy?,Chapter 1 Preface,1、 About petroleum industry Petroleum industry is the most important industry to world economy and society. Petroleum products are the most important industrial material and fuel. World petroleum production controls world iron and steel industry, petroc

8、hemical industry , traffic and communication, etc. Petroleum products are directly interrelated to the daily life of almost all people around the world.,Chapter 1 Preface,2、The reserve volume and producing capacity in China and the world oil and gas production in China in 1999 world oil and gas prod

9、uction in 1999 world oil and gas reserve volume in 1999,In 21st century natural gas will becomes very important energy source,Coal,coal,wood,solar,energy,natural gas,oil,The world energy source replacement,Chapter 1 Preface,3、About our course The aim To study the basic contents of petroleum geology

10、; To train your petroleum geology ideation; Points for attention Study in classroom and Self study after school. Discuss with others including me. The power Pay great attention! + study hard!,Study contents of our course,Petroleum reservoirs/pools (our part 2) and Their formation (our part 3) So, in

11、 short , Petroleum Geology Reservoirs and their formation.,understanding,Trap a cup Likes reservoir a cup of tea (pools),Lecture content,Part 1 Introduction Part 2 Petroleum reservoirs and the fluids in it Part 3 The formation of petroleum reservoir,Petroleum Geology,Part 2 Petroleum Reservoirs and

12、the fluids in it,What are the fluids in reservoirs? Oil, gas and water, Their chemical and physical properties. What are the rocks containing and sealing petroleum? reservoir rocks, cap rocks, Capability or performance of reservoir rocks; What are the reservoirs? Their measurement, classification, c

13、haracters,Part 2 Petroleum Reservoirs and the fluids in it,Chapter 2 The fluids in reservoir- oil, natural gas and oil -field water Chapter 3 The reservoir rocks and cap rocks Chapter 4 The traps and reservoir of oil and gas,Chapter 2 The fluids in reservoir-oil, natural gas and oil -field water,Sec

14、tion 1 The oil (petroleum) Section 2 The natural gas: Section 3 The oil-field waters,Section 1 The oil /petroleum,1.1 Definition of petroleum 1.2 The chemical properties of petroleum 1.3 Distillation and uses of petroleum 1.4 Classification of crude oils 1.5 The difference between marine and terrige

15、nous petroleum 1.6 Physical properties of petroleum,1.1 Definition of petroleum,The word petroleum originates from the Latin words petra(“rock”) and oleum(“oil”), just as its Chinese word, 石油 means “石” and “油”. In common usage, it means any hydrocarbon(烃) mixture that can be produced from undergroun

16、d rocks through a drill pipe. Definition: Petroleum is a kind of mineral resources that occurs in the earth as semi-solids, liquids or gases, or mutual solutions of these.,General feature,Petroleum is mixture of hydrocarbons usually with some contaminant non-hydrocarbon compounds of nitrogen, sulfur

17、 and oxygen in small amount; also of vanadium(V) and nickel(Ni). The proportions of the constituent hydrocarbons and the contaminant are different in each petroleum accumulation or oil field. The Physical properties of petroleum are different in each accumulation/field.,1.2 The chemical properties o

18、f petroleum,A. Elemental composition The main elements are Carbon and Hydrogen; The minor elements Sulfur,Nitrogen, and Oxygen less than 3%; Traces of heavy metals,such as V and Ni, also are present.,Table 1-1 Elemental composition of fossil fuels and kerogen(wt%) (Hunt,1996),From gas to kerogen, th

19、ere is a marked decrease in hydrogen and a corresponding increase in sulfur, nitrogen, and oxygen relative to carbon.,The alkane series=Paraffins,The general formula is CnH2n+2. C1-4 are gases: methane/CH4，ethane/C2H6，propane/ C3H8，butane/C4H10 C5-20 are liquids C20+ are usually waxy solids. In CnH2

20、n+2 in crude oil, usually n80. Alkane series can be divided into 2 types: a. the normal alkanes: n-alkanes b. the isomeric arkanes: i-alkanes,MethaneEthanePropaneButanePentaneHexaneHeptane,Isobutane Dimethyl butane Trimethyl pentane,C. Naphthene or Cycloparaffin,general formular: CnH2n, , ,n5 The Cy

21、cloparaffins that are formed by joining the carbons in ring are the most common molecular structures in petroleum. The most common naphthenes in petroleum are methylcyclopentane(环戊烷) and methylcyclohexane(环己烷). The average crude oil contains about 50% naphthenes, with the quantities increasing in th

22、e heavier fractions and decreasing in the lighter fractions.,Naphthenes,D. The aromatic Hydrocarbons,With general formular CnH2n-6; The term aromatic hydrocarbon originated from pleasant-smelling compounds in petroleum. However , most HCs have very little odor in pure state. All aromatic HCs contain

23、 at least one benzene ring. They are unsaturated cycloHC series with double bonds between carbon atoms, likes benzeneand its homologous: Benzene(苯), Naphthalene(奈), Paranaphthalene(蒽)。,E. Nitrgen,sulfur, and Oxygen compounds(Asphaltics),They are complex structural arrangements made of naphthenoaroma

24、tic nuclei, with chains and heteroatoms (O,N,S). a)Sulfur compounds：average content of sulfur in crude oil is 0.65% by weight. Low or high sulfur crude oil: S1.0% b)Nitrogen compounds：Nitrogen content is usually much lower than sulfur content in crude oil. The average nitrogen content is 0.094% by w

25、t, in most crude oil nitrogen less than 0.2%.The most important nitrogen compound is porphyrin: Nickel(Ni) and Vanadium(V) porphyrin。 c)Oxygen compounds: as saturated fatty acids:phenols,About porphyrin,Porphyrins are characterized by a tetrapyrrolic nucleus(4 pyrrole rings), probably inherited from

26、 chlorophyll or hemin So nickel porphyrin and vanadium porphyrin are biological markers: Petroleum come from organic matter. Chlorophyll, the green photosynthetic pigment of plants; Hemin, the red pigment of animal blood. There are other metals, like iron(Fe), zinc(Zn), copper(Cu), lead(Pb), arsenic

27、(As), molybdenum(Mo), cobalt(Co), magnesium(Mg), chromium(Cr) etc, in petroleum, but only little.,1.3 Distillation and uses of petroleum,Distillation is the principal method for separating crude oil into useful products. The common distillate fractions are: gasoline(C5-C10), kerosine (C11-C13) , die

28、sel oil (C14-C18) , heavy gas oil (C19-C25), lubricating oil (C26-C40), residuum (C40) , etc.,00-10-16,A refinery tower is equivalent to a series of individual distillation flasks, in which the distillate fractions(馏份) from the first flask is condensed in the second flask, and then redistilled to pr

29、oduce a distillate for the third flask.,A distillation tower,Aromatics,Naphthenoaromatics,Nitrogen, sulfur,and oxygen compounds,The light gasoline fraction of oil is dominated by the normal, iso-,and cycroparaffins. From Gasoline into the heavier fractions, There is a marked increases in the Aromati

30、cs+ naphthenoaromatics.,After diesel,NSO compounds content increases markedly, the residuum is dominated by NSO compounds.,1.4 Classification of crude oils,Some classifications have been proposed by geochemists and petroleum refiners. A classification of petroleum has been proposed by Tissot and Wel

31、te based primarily on the content of the various structural types of hydrocarbon: P =Paraffin N=Naphthenes AA=Aromatics and Asphaltenes+resins S= Saturated hydrocarbon,1.4 Classification of crude oils,1)S50%,AA40%,PN: Paraffinic oils 2)S50%,AA40%,NP: Naphthenic oils 3)S50%,AA10%: Aromatic intermedia

32、te oils 5)S50%,AA50%,P10%,N25%: Aromatic naphthenic oils 6)S50%,AA50%,P10%,N25%: Aromatic Asphaltic oils,Paraffinic,Naphthenic,Paraffinic naphthenic,Aromatic intermediate,Aromatic naphthenic,Aromatic Asphaltic,P =Paraffin,N=Naphthenes,AA=Aromatics and Asphaltenes+resins,25,40,50,50,40,60,50,60,90,10

33、,75,1.5 The difference between marine petroleum and terrigenous petroleum,1. On oil type 2. On wax content 3. On sulfur content 4. On trace element content, as V,Ni, V/Ni 5. On stable isotopes of carbon,Self study it,1.6 Physical properties of petroleum,1) Density and Specific gravity 2) Viscosity(粘

34、度) 3) Fluorescence(荧光性) 4) Color 5) Smell 6) Calorific Value,1) Density and Specific gravity,Oil density usually less than 1000kg/m3, oil is lighter than water. But some crude oils, dense oils, can heavier than water, their density can larger than 1000kg/ m3 . To develop dense oil is very difficult,

35、.,Viscosity is an inverse measure of the ability of a substance(fluid) to flow. The greater the viscosity of a fluid, the more difficult it flows. Oil viscosity is generally dependent chiefly on the amount of gas dissolved in It and on the temperature.,2) Viscosity,3) Fluorescence(荧光性),All oils exhi

36、bit more or less fluorescence, the aromatic oils are the most fluorescent. Fluorescent color of crude oil can be yellow, green, or blue. Fluorescence must be observed under ultraviolet radiation. Fluorescence is used in well logging to locate oil shows in cores, cuttings, and drilling mud.,4) Color5

37、) Smell6) Calorific Value,Self study,Now,we have finished section 1. Lets start section 2,Section 2 The Natural Gas,2.1 Concepts about natural gas 2.2 The chemical proportion of natural gas 2.3 The physical properties of natural gas 2.4 About gas hydrate,2.1 Concepts about natural gas,Natural gas: I

38、n this course, it means the gas occurs in lithosphere. Associated gas: the gas occurs with oil Non-associated gas: the gas occurs alone. Aggregated gas: The gas in gas reservoir， Condensed gas， The gas in oil and gas reservoir Decentralized gas: The gas dissolved in oil，the gas dissolved in oil-fiel

39、ds water, the liquefied gas, the coal bed gas, and the methane hydrate(甲烷水合物).,2.2 The chemical proportion of natural gas,A.Hydrocarbon gas: Methane/CH4, main composition of gas Ethane/ C2H6, Propane/ C3H8, takes small amount of gas Butane/ C4H10 B.Non-hydrocarbon gas: N2, CO2, H2S, H2, CO, SO2, Hg,

40、 etc.,2.3 The Physical Properties,A.Density and special gravity of natural gas Density means the weight of a given volume, such as kilograms per cubic meter. The density of a natural gas depends on its pressure(p), temperature(t), apparent molecular weight(m) and compressibility factor(z). Dg=0.1196

41、571*p*mg/(z*t),2.3 The Physical Properties,B. The density of nature gas under the reservoir condition is larger than that of standard gas, usually 150-250kg/m3. The special gravity of natural gas means the ratio of natural gas density to that of air. Also the ratio of molecular weight of natural gas

42、 to that of air(28.97): rg=mg/28.97,2.3 The Physical Properties,C. The solubility a. in water Henly formula: Q=C*P Q:solubility, C:solution coefficient, P: pressure. b. in crude oil the solubility depends on the pressure, temperature, composition of gas, the content of light HC in crude oil.,2.4 Abo

43、ut the gas hydrate,Gas hydrates are crystalline compounds in which the ice structure of water is distorted to form cages that contain the gas molecules. The hydrates are solids resembling wet snow in appearance, and they form both above and below 0under specific pressure- temperature conditions. The

44、 water molecules form two kinds of unit cell structures .,The smaller unit structure contains 46 water molecules, which can hold up to 8 methane molecules. Gases such as CH4, C2H6, H2S, and CO2 can fit into this structure. The larger unit cell contains 136 molecules of water. Gases such as propane a

45、nd iso-butane can fit into it. These are the only gaseous hydrocarbons that form hydrates. The pentanes and n-butane molecules are too large.,A methane hydrate in which all the ice stages are completely filled with methane contains about 172 m3 CH4 of hydrate at STP. In nature the more typical ratio

46、 is 40 m3 CH4/m3 of hydrate. Natural hydrate units generally have six or seven H2O molecules per CH4 molecule.,The pressure-temperature diagram for methane and a 0.6 gravity gas (C1 +C2 +C3) is shown in Figure 7-8. Hydrates are formed by increasing pressures and are decomposed by increasing temperat

47、ures. Since the pressure required to form gas hydrates increases logarithmically as the temperatures increase linearly, it is apparent that the hydrates in most sedimentary basins decompose in the temperature range 70 to 80(21 to 27), because the pressures are inadequate to preserve them.,HydrateAnd

48、 ice,Hydrate And water,Hydrate usually occurs in permafrost territory, polar region, and deep sea bottom sediment. It is estimated that there is very rich amount of hydrate around the world. But, now it is difficult to exploit hydrate in technical.,Section 3 The Oil-field Waters,3.1 Concepts 3.2 Sou

49、rce of oil-field waters 3.3 Chemical composition and degree of mineralization 3.4 The classification,3.1 Concepts,Oilfield waters in general are termed brines. The water found in petroleum reservoir rocks is usually referred to as interstitial water, but it is improbable that the water which now exi

50、sts in the pores of a reservoir rock is the same water which was in the same group of pores at the time when the sediment was first laid down.,The expressions bottom water meaning water underlying the oil and edge water“ means water lying down dip and therefore laterally with respect to the oil zone

51、. Clearly, both terms are concerned with the same body of water in a given reservoir rock. Also: top water, intermediary waters.,Edge water,Bottom water,Interbedded water,3.2 Source of oil-field waters,Sedimentation water: the water in which sediments were deposited. Infiltration water: the water th

52、at has fallen as rain water and has filled up the porous and permeable rocks. Transform water: the water transformed from clay mineral or organic matter. Plutonic(火成岩的) water: the water formed by magmatism(岩浆作用)or metamorphism（变质作用）.,00-10-18,3.3 The chemical composition and degree of mineralization

53、,A. Inorganic: 6 kinds of ion: sodium(Na+)+potassium(k+), calcium(ca2+), magnessium(mg2+) chlorides(Cl-), sulfates(SO42-), bicarbonates(HCO3-)+carbonates(CO32-), and other trace elements.,3 positive ions,3 negative ions,B. Organic: HC, Phenols(苯酚) and salt of organic Acid Indeed, it has been propose

54、d that a lateral increase in the benzene content of the brine in a given stratum may point towards an oil accumulation in that stratum.,C. the gas dissolved in it,The degree of mineralization,Its also called concentration or salinity of oilfield water. means the total amount of dissolved solids in g

55、iven volume of oilfield water(g/l). Because of the dissolved solids is much, usually the oilfield water can be called oil-field brines. The mineralization degree of marine oil-field waters is usually higher than that of terrigenous oilfield water.,3.4 The classification of oilfield waters,The classi

56、fication of oil-field water proposed by Sulin was based on the value of Na+/Cl-, (Na+Cl-)/SO42-, and (Cl-Na+)/Mg2+ There are 4 types of oilfield water: A).Type Na2SO4: usually near the surface B).Type NaHCO3 C).Type MgCl2 D).Type CaCl2: was the main type of oil-field water.,0,Mg,Cl-Na,SO4,Na - Cl,Ty

57、pe Na2SO4,Type NaHCO3,Type MgCl2,Type CaCl2,(Cl-Na)/Mg=1,(Na-Cl)/SO4=1,45,type CaCl2: Na+/Cl-1,type Na2SO4 : Na+/Cl-1, (Na+ Cl-)/ SO42- 1,type MgCl2: Na+/Cl-1, (Cl-Na+)/Mg2+ 1,type NaHCO3 : Na+/Cl-1, (Na+ Cl-)/ SO42- 1,SummaryThe keystone of chapter 1 is:,a)definition of oil, gas, and oilfield water

58、; b)chemical composition of them, especially oil; c)classification of them,Questions?,1. What is the molecular formula of petroleum? What is its density? 2. Lets say a crude oil sample, its paraffin content was 40% in wt, its naphthene content was 5%, what type of oil does it belong to? 3. How many

59、types can oilfield water be divided into by Sulin? Which type is the main oilfield water?,Part 2 Petroleum Reservoirs and the Fluids in It,Chapter 2 The fluids in reservoir- oil, natural gas and oil -field water Chapter 3 The reservoir rocks and cap rocks Chapter 4 The traps and reservoir of oil and ga