Structural traps occur when the reservoir formation deforms. The petroleum system is a unifying concept that encompasses all of the disparate elements and processes of petroleum geology. Petroleum or crude oil is a complex, naturally occurring liquid mixture containing mostly. Wielchowsky exxon exploration company houston, texas, u.
The principal source rocks are lacustrine to marine shales of the toarcian togur bed. If there is a layer of impermeable rock present in this dome shape, then hydrocarbons can accumulate at the crest until the anticline is filled to the spill point the highest point where hydrocarbons can escape the anticline. Exploring for oil and gas traps treatise of petroleum geology, handbook of petroleum geology series treatise. Geology is the science that deals with the history and structure of the earth and its life forms, especially as recorded in the rock record. Combination traps compressional anticlines compactional anticlines drape anticlines. The khazzan gas accumulation, a giant combination trap in the. Ulmishek foreword this report was prepared as part of the world energy project of the u.
Broadhead, new mexico bureau of geology and mineral resources, a division of new mexico institute of mining and technology introduction the oil and natural gas that are produced from oil and gas fields reside in porous and permeable rocks reservoirs in which these liquids have collected and accumulated. Treatise of petroleum geology handbook of petroleum geology. May 24, 2017 introduction migration of petroleum petroleum traps structural traps stratigraphic traps combination traps timing of trap formation conclusion references 3. Two types of petroleum traps are structural and stratigraphic. Structural trap petroleum geology petroleum reservoir. Traps with two or more trapping elements are called combination traps. A basic understanding of its concepts and processes is essential in the petroleum industry, for it is used to predict where oil accumulations might occur. Stratigraphic traps stratigraphic traps are usually caused by changes in rock quality.
These methods include drilling, geophysical exploration techniques, wireline logging, and subsurface geological mapping. Lateral variation in magnetic susceptibility and remanence give rise to spatial variations in the magnetic field it is expressed in so called magnetic anomalies, i. A traps is a an arrangement of rock layers that contains an. Petroleum geologists are the men and women who know how to read the story told by the very earth beneath our feet in order to find oil and natural gas, which are vital resources in our lives. Petroleum exploration in queensland, australia bulletin. A facies and palaeogeographybased approach for analysis of. The nature of gas and oil the earths crust where we find time deformation of sedimentary rocks sandstone reservoir rocks carbonate reservoir rocks sedimentary rock distribution mapping ocean environment and plate tectonics source rocks, generation, migration, and. Petroleum exploration in queensland, australia bulletin of. Typical caprocks are compacted shales, evaporites, and tightly cemented sandstones and carbonate rocks. The oil and gas within a trap is part of a petroleum system, whereas the trap itself is part of one or more. Stratigraphic traps are formed by deposition of reservoir rock, such as river channel or reef, or by erosion of reservoir rock, such as an angular unconformity. Agreement breaks down, however, when attempts are made to subdivide these groups. Advanced petroleum geology west virginia university.
Petroleum traps structural traps stratigraphic traps combination traps. Combination traps occur where structural nosing andor faulting modifies the hydrocarbon distribution but is not the sole reason for the accumulation. Gas oil water water oilwater contact gasoil contact traps are usually classified according to the mechanism that produces the hydrocarbon accumulation. Traps can be structural, stratigraphic or a combination of both. Anticlinal trap top seal rock impermeable reservoir rock potential porouspermeable migration route. Petroleum system is a core concept of petroleum geologythe study of oil and gas formation and exploration with its associated processes such as oil origin, occurrence, migration and their accumulationwhich unifies interdependent processes and key elements in. The distribution of these hydrocarbon accumulations is. This chapter discusses its application to petroleum exploration.
Exploring for oil and gas traps treatise of petroleum geology, handbook of petroleum geology series treatise of petroleum geology, handbook of petroleum geology series edward a. Carbonate reefs and buildups are found on top of and. The interaction of three factors results in several different predictable patterns of wrenchfaultrelated petroleum traps. Structural traps american association of petroleum. Hydrocarbon traps are any combination of physical factors that promote the accumulation and retention of petroleum in one location. D underlying this sequence of events is the fundamental control of economics. It can be structural traps or stratigraphic traps or combination of these factors. The purposes of this association are to advance the science of geology. Because tectonics ultimately control deposition and erosion, however, few stratigraphic traps are completely without structural influence. It is related to sediment deposition or erosion and is bounded on one or more sides by zones of low permeability. Reservoirs structural traps these anticline traps were filled with petroleum when it moved in form its source below. Traps are structural, stratigraphic, or a combination of the two.
Hydrocarbon traps form where permeable reservoir rocks carbonates, sandstones are covered by rocks with low permeability caprocks that are capable of preventing the hydrocarbons from further upward migration. Fault traps are formed by breaking or shearing and offsetting of strata. Petroleum geology petroleum geology petroleum reservoir. To classify a combination trap informally, list the primary trap element first, followed by secondary and. The buck peak field shown in figure 3 is an example of a combination structural trap. It refers to the specific set of geological disciplines that are applied to the search for hydrocarbons oil exploration. Geology is a fundamental aspect of the modern effort to locate and usefully exploit hydrocarbons petroleum, natural gas. These source rock plays, both oil and gas, will only grow bigger with time.
The deliberate search for stratigraphic and subtle combination traps. Petroleum is the general term used for all the natural hydrocarbons found in rocks. Structural traps are the most important type of trap as they represent the majority of the worlds discovered. Pge251 introduction to petroleum and natural gas engineering. Such traps are called combination traps and will be discussed later in this lecture. Structural traps are the most important type of trap as they represent the majority of the worlds discovered petroleum resources. Most petroleum geologists classify traps according to the scheme proposed by levorsen. Ted beaumont is an independent petroleum geologist from tulsa. The diagram in figure 4 shows the formal classification for the buck peak field, which is a. The trap classification scheme proposed here uses levorsens scheme as a foundation and adds new trap types discovered since 1954. Petroleum geology is the study of origin, occurrence, movement, accumulation, and exploration of hydrocarbon fuels.
Combination traps occur where structural nosing andor faulting modifies the. Petroleum geology plays an important role in todays society. Many traps result from both of these factors stratistructural or combination traps. A second major class of petroleum traps is the stratigraphic trap. In petroleum geology, a trap is a geological structure affecting the reservoir rock and caprock of a petroleum system allowing the accumulation of hydrocarbons in a reservoir. The accumulation is associated with cambrian barik sandstone member reservoirs, in a semiregional combination stratigraphicstructural trap. The total petroleum system was asssessed as a single assessment unit. Es486 petroleum geology final exam study guide winter 2017. Petroleum trap, underground rock formation that blocks the movement of petroleum and causes it to accumulate in a reservoir that can be exploited. Es486 final final study w2019 western oregon university. Combination traps combination traps that combine more than one type of trap are common in petroleum reservoirs. Marine and petroleum geology is the preeminent international forum for the exchange of multidisciplinary concepts, interpretations and techniques for all concerned with marine and petroleum geology in industry, government and academia.
Traps are usually classified according to the mechanism that produces the hydrocarbon accumulation. Most stratigraphic and combination traps require top, lateral, and bottom seals. Advances and perspectives on stratigraphic trap exploration. In recent years, stratigraphic and combination traps such as buzzard uk north sea and jubilee ghana have attracted much industry attention. The american association of petroleum geologists is an international organization with over 38,000 members in 100plus countries. This third edition of elements of petroleum geology is completely. Introduction migration of petroleum petroleum traps structural traps stratigraphic traps combination traps timing of trap formation. This book is a usefulprimer for geophysicists, geologists, and petroleum engineers in the oil industry who wish to expand their knowledge beyond their specialized area. The northern onshore and offshore parts of the basin are included in the northern west siberian mesozoic composite. Petroleum geologist broadly classify traps into three categories that are based on. Introduction migration of petroleum petroleum traps structural traps stratigraphic traps combination traps timing of trap formation conclusion references 3. A facies and palaeogeographybased approach for analysis. The central problem with many stratigraphic and combination traps remains the number of seals and. The petroleum geology of the niger delta 1,2 is characterised by the.
Petroleum geology for nongeologists december 1516, 2016 houston, tx page. This combination of rock can take several forms, but they all prevent the upward migration of oil and natural gas up through the reservoir rock. Practical application of petroleum systems can be used in exploration, resource evaluation, and research. Abstract trap identification is a first step in prospect evaluation and an important part of any exploration or assessment program. Download as pptx, pdf, txt or read online from scribd. Petroleum geology and resources of the west siberian basin. This third edition of elements of petroleum geology is completely updated and revised to reflect the vast changes in the field since publication of the second edition. Petroleum geology and resources of the west siberian basin, russia by gregory f.
Modified from exploring for oil and gas traps treatise of petroleum g eology aapg 1999. The caprock need not be 100% impermeable to water, oil or gas. In the project, the world was divided into 8 regions and 937 geologic provinces. The oil is accompanied always by water and often by natural gas. Pdf application of geology in petroleum exploration and. Thus petroleum geology lies within a continuum of disciplines, beginning with geophysics and ending with petroleum engineering, but overlapping both in time and subject matter. Levorsens scheme breaks traps into three basic types. In the composite petroleum system, hydrocarbons are reservoired in the lower cretaceous thamama group. Structural traps american association of petroleum geologists.
The two main groups of traps are those that are formed by structural deformation of rocks structural traps, and those that are related to depositional or diagenetic features in the sedimentary sequence stratigraphic traps. Quantitative approach based upon a producing field. Underground rock formation that blocks the movement of petroleum and cause accumulation. Most of the undiscovered resources are expected in stratigraphic and combination traps. Es486 petroleum geology final exam study guide winter 2017 exam format twopart exam, thursday march 23, 2017. Stratigraphic trap a second major class of oil traps is the stratigraphic trap. Exploring for oil and gas traps pages 31 334, edited by edward a. Oil and gas traps, sometimes referred to as petroleum traps are below ground traps where a permeable reservoir rock is covered by some low permeability cap rock.
Exploring for oil and gas traps series treatise in petroleum geology part traps, trap types, and the petroleum system chapter classification of exploration traps author richard r. Rocks trap are formed from a wide variety of combinations of structural and. Structural traps are formed by deformation of reservoir rock, such as by folding or faulting. Es486 petroleum geology final exam study guide winter 2019 exam format twopart exam, thursday march 21, 2019. This article outlines the background to the discovery of khazzan and describes our understanding of its geology and petroleum systems and the study work used to support screening, appraisal, and. The provinces have been ranked according to the discovered oil and.
Such trap types are generally considered higher risk than structural traps, and understanding them represents a challenge for explorers, as numerous less successful often amplitudedriven attempts have demonstrated. Broadhead, new mexico bureau of geology and mineral resources, a division of new mexico institute of mining and technology introduction the oil and natural gas that are produced from oil and gas fields reside in porous. As shown in figure 84, oil traps consist of hydrocarbon fluids held in porous rock covered by a cap rock. Exploring for oil and gas traps series treatise in petroleum geology part traps, trap types, and the petroleum system.
An anticline is an area of the subsurface where the strata have been pushed into forming a domed shape. Some structural traps are combinations of the three structural trap regimes. Hydrodynamic traps occur where the downward movement of water prevents the upward movement of oil without normal structure or stratigraphic closure. Fundamentals of petroleum geology pdf free download. The impervious rock covering the reservoir rocks is called a cap rock. Used by corporate training departments and colleges worldwide, this is the most complete upstream guide available. Because tectonics ultimately control deposition and erosion, however, few stratigraphic traps read more. Nontechnical guide to petroleum geology, exploration. The two main groups of traps are those that are formed by structural deformation of rocks structural traps, and those that are related to depositional or diagenetic features in. A third group, combination traps, is caused by a combination of processes. Exploring for oil and gas traps treatise of petroleum. If the diameter of the tube is sufficiently small, then the combination of surface tension.