1、油层物理学油层物理学Physical Properties of Petroleum Reservoir石油工程学院石油工程学院油藏工程系油藏工程系：李爱芬李爱芬2010年年9月月 李爱芬，山东安丘人；李爱芬，山东安丘人；8585年毕业于华东石油大学采年毕业于华东石油大学采油专业；油专业；教授，博士，博士生导师。教授，博士，博士生导师。主要研究领域：主要研究领域：油气渗流机理（低渗、缝洞），提高原油采收率油气渗流机理（低渗、缝洞），提高原油采收率机理，油气井出砂及防砂，储层敏感性评价，油藏机理，油气井出砂及防砂，储层敏感性评价，油藏流体及岩石物性研究。流体及岩石物性研究。教学讲授课程：教学讲授
2、课程：本科生：油层物理本科生：油层物理(汉语、双语、实验汉语、双语、实验)；研究生：渗流物理，气藏工程研究生：渗流物理，气藏工程(双语双语)，油藏工程，油藏工程(Reservoir Engineering1)(Reservoir Engineering1)等。等。个人简介个人简介 石油深埋在地下岩石孔隙中石油深埋在地下岩石孔隙中:前前 言言 石油是一种不可再生的资源。油田开发的好坏，石油是一种不可再生的资源。油田开发的好坏，很大程度上取决于对油藏的认识程度。很大程度上取决于对油藏的认识程度。19491949年，美国年，美国M.MusketM.Musket出版出版“采油物理原理采油物理原理”把以
3、前关于把以前关于油藏岩石、流体物性油藏岩石、流体物性方面的概念与研究成果系统方面的概念与研究成果系统化和理论化，使岩石、流体物性与化和理论化，使岩石、流体物性与各类油藏各类油藏紧密结合起来。紧密结合起来。19561956年，苏联年，苏联.卡佳霍夫卡佳霍夫撰著撰著“油层物理基础油层物理基础”该书是该书是“油层物理油层物理”从采油工程中单独分科的起点，随后得到从采油工程中单独分科的起点，随后得到了广泛而深入的发展。了广泛而深入的发展。6060年代末，石油大学年代末，石油大学洪世铎洪世铎在在卡佳霍夫卡佳霍夫课本的基础课本的基础上，首次在国内编著上，首次在国内编著中文版中文版“油层物理基础油层物理基础
4、”。从此。从此油层物理在油层物理在国内国内成为一门独立的学科。成为一门独立的学科。“油层物理油层物理”起源起源：最早研究内容与油藏工程混在一起。最早研究内容与油藏工程混在一起。Reservoir having artesian water(露头水露头水).油藏类型：油藏类型：Reservoir having bottom water and gas-cap油藏类型：油藏类型：Reservoir with pinchout boundary(岩性尖灭油藏）岩性尖灭油藏）高89-3高89-4高89高89-5高89-1高89-8油藏物理油藏物理石油地质、有机化石油地质、有机化学、化学原理学、化学原理
5、 渗流力学渗流力学 油藏工程油藏工程 油藏数值模拟油藏数值模拟 采油工程采油工程 我国老油田油田：多数已进入开发中后期，我国老油田油田：多数已进入开发中后期，含水高含水高（很多（很多90%90%），但但采出程度低采出程度低（陆上陆上15155050,海上油海上油田田18C16:Solid (paraffin 石蜡石蜡)22 nnHCAlkanes is the main components:1.1 Chemical composition of petroleumparaffinsa(石蜡石蜡)Nonhydrocarbons(非烃非烃)are compounds of oxygen,sulf
6、ur,nitrogen of alkanes(是胶质、沥青质的主要成分是胶质、沥青质的主要成分)。1.2 Commercial value of Petroleum（商品性质）（商品性质）:Commercial value of a petroleum liquid are specific gravity,viscosity,freezing point(凝固点凝固点),asphalt(沥青沥青)content,sulfur content（硫化物）（硫化物）etc.Although the quantities of these nonhydrocarbons are very small
7、,they exert great influences on some of the properties of petroleum,such as color,specific gravity,viscosity and interfacial tension.When the reservoir is developed,the states of the hydrocarbon depends upon(1)the composition of the hydrocarbon fluid,(2)the pressure and temperature.2.Basic concepts
8、in study of phase behavior(1)System(体系体系):a amount of substances within given boundaries under specific conditions composed of a number of components.(2)Phase(相相)is any homogeneous and physically distinct part of a system.There is a definite bounding surfaces between different phases.A phase can con
9、sist of several components.(4)Composition(组成组成)is the components and their relative quantities of a system.(5)p-T phase diagram(相图相图)is the diagram which shows the conditions of temperature and pressure for which different phases exist.(3)Components(组分组分)is the substance which consist of the system.
10、such as the methane,ethane,propane,butane,etc in the petroleum.p-T diagram is the most often used one in petroleum industry.3.1 phase behavior of one component system(1)The Characteristic of one component system 3.Phase Diagram of one-,two-,multi-component system P1 P2=Pd=Pb Pb Pb Pb P3Dew point(露点露
11、点)is the point at which only a small drop of liquid exist(or condensate).Bubble point(泡点泡点)is the point at which the first few molecules leave the liquid and form a small bubble of gas.Characteristic：bubble point(bubble point(泡点压力泡点压力)dew point(dew point(露点压力露点压力)。(2)P-v diagram of one component sys
12、tem As temperature increases,the volume change from gas state to liquid state decreases.At Tc the length of horizontal line becomes a point C.If temperature Tc,the gas can not be liquefied.Point C is called critical point.Pc-The critical pressure Tc-The critical temperature(3)P-T diagram of one comp
13、onent system (1)It is a single linethe vapor pressure line,the locus of bubble points and dew points of the pure substance.(2)The critical point C is the highest pressure and highest temperature point at which gas and liquid can coexist.At point C,all the intensive(内在的内在的)properties of gas and liqui
14、d phases,such as viscosity,density etc.become identical.(3)The phase diagram is divided into the gas region,liquid region and the two-phase region.liquid regiongas regiontwo-phase region(4)With molecular increases the vapor pressure line move to the right side.The use of phase diagram：to determine t
15、he phase behavior of the component at different P and T.K:Initially entirely liquidI:Bubble point,Gas,liquid coexistP=CI:Dew point,Gas,liquid coexistPPG:Entirely in gas stateExample:Constant temperature process KIG:3.2 Phase Behavior Of Two-Component Systems(1)It is an envelope(开口环形开口环形)line FC-bubb
16、le point line,line EC-dew point line.(2)The region bounded by Pb line and Pd line is the two-phase region.Above and to the left of the bubble point line,the mixture exists as a liquid.Below and to the right of the dew point line,the mixture exists as a gas.(3)The critical point C is the point at whi
17、ch the bubble point line and the dew point line join.(1)The phase envelope for a mixture lie between the vapor pressure curves of the pure constituents.Fig.1.1.6 P-T diagram for the ethane-n-heptane system.(2)As the composition of the mixture becomes more evenly distributed between the constituents,
18、the two-phase region increases in size.P7The characteristic of two phase diagram(3)As one constituent(组分组分)becomes more predominant,the phase envelope tends to shift to the vapor-pressure curve of the major pure component.(4)The critical temperature Tc of the mixture lies between the critical temper
19、atures of the two pure components.Pc is usually high then Pc of the two components.Locus of critical points(临界点轨迹线临界点轨迹线)(5)a larger difference in molecular size of the components causes the mixtures to have very large critical pressures.6)a small difference in molecular size of the components cause
20、s the small critical pressures.测定原理：测定原理：3.3 Phase behavior of multi-component system (多组分相图多组分相图)The shape is an envelop.(1)Characteristic3.3 Phase behavior of multi-component system (多组分相图多组分相图)Fig.1.1.8 Phase diagram of a multi-component system C Critical point；KC-Bubble point curve.OC-Dew point
21、curve.Liquid region-Above the bubble point line；Gas region-Below and to the right of the dew point line Two phase region-The region bounded the bubble point line and dew point line.Dotted lines-the iso vol lines(quality lines)-等液量线等液量线Liquid regionGas regionGas regionTwo phase region-Cricondenbar P(
22、临界凝析压力）临界凝析压力）the highest pressure on the saturation envelope.Cricondentherm T(临界凝析温度临界凝析温度)the highest temperature on the saturation envelope.The shaded area-Retrograde region where condensation or vaporization occurs in reverse to the conventional behavior.-isothermal retrograde condensation-isoba
23、ric retrograde condensation(2)Retrograde Condensation(反常凝析）反常凝析）Point A:entirely gasPoint B:Upper dew pointPoint D:maximum amount of liquid Point E:Lower dew pointPoint F:entirely gasAt normal condition,a decrease in pressure causes a change of phase from liquid to gas.But in condensate gas reservoi
24、r,the process is exactly the reverse of normal one,hence call it retrograde condensation.the hydrocarbon system exists as a single liquid.It is an undersaturated oil reservoir（未（未饱和油藏）饱和油藏）(3)The use of phase diagram of multi-component systemTo determine classification of the hydrocarbon systemTo de
25、termine the phase behavior during production period.Example:point J：Point A：a condensate gas The reservoir temperature lies between the critical temperature and the cricondentherm of the system.The reservoir condition is usually above the shade zone.Point I：the initial reservoir conditions on the bu
26、bble point curve,the oil is said to be saturated（饱和油藏）（饱和油藏）.Gas cap may be exited in this situation.Point F：Gas reservoir；4 Phase Diagrams of Several Typical Oil/Gas ReservoirsConcepts:(1)Low-shrinkage crude oil is the oil with a low shrinkage in volume(2)high-shrinkage crude oil is the oil with a
27、high shrinkage in volume A crude oil contains a certain amount of lighter hydrocarbons.When it is produced to the surface,the lighter hydrocarbons evolve from the oil and form gas.This will result in a shrinkage in oil volume.The larger amount of lighter hydrocarbons contained in the oil,the large s
28、hrinkage will occur in the oil volume when it is produced to the surface.4.1 The low-shrinkage crude oil The phase diagram covers a wide temperature range.The iso-vol lines are near the dew point line.Fig.1.1.10 low-shrinkage crude oil Line l23-phase behavior in reservoir.Sseparator conditionCharact
29、eristic:contains large amounts of heavy constituents,the gas-oil ratio is small(0.876).The stock-tank oil is very dark.Fig.1.1.11 high-shrinkage crude oil 4.2 The high-shrinkage crude oilThe area of the diagram is smaller.Iso-vol lines are shifted upwards toward the bubble-point line.-a small reduct
30、ion in pressure below the bubble point 2,causes the release of a large amount of gas in the reservoir.Line l23-phase behavior in reservoir.Sseparator conditioncontains more lighter hydrocarbons,higher producing gas-oil ratio(901500m3/m3),the specific gravity less than 0.78.The stock-tank oil is colo
31、red.The phase diagram is smaller than that of oils The reservoir temperature is higher than the critical temperature and lower than the cricondentherm.4.3 Phase Diagram For Retrograde GasFig.1.1.12 retrograde gas Stock-tank liquid produced from retrograde gas reservoirs often is called condensate.Th
32、e liquid can be lightly colored,4.4 Phase Diagram For Wet GasThe area of phase diagram is small.No liquid is formed in the reservoir Separator conditions lie within the phase envelope.Fig.1.1.13 wet gas Stock-tank liquid-condensate.The liquid almost has no color,The type of reservoir is mainly deter
33、mined by phase diagram.4.5 Phase Diagram For Dry GasThe mixture is solely gas in the reservoir.Separator conditions fall outside the phase envelope.Fig.1.1.14 dry gas No liquid is formed either in the reservoir or at the surface.low-shrinkage crude oil high-shrinkage crude oil retrograde gas wet gas
34、 dry gas From the low-shrinkage crude oil to the dry gas,the phase diagrams have the following characteristics:(1)The critical points shift from right to left.(2)The phase envelopes become smaller.The oils have a broader two-phase region than the gases.(3)The iso-vols shift towards the bubble point lines.Conclusion to phase behavior
