Fundamentals of petroleum geology pdf free download. The book, an addition to the handbook set of the treatise of petroleum geology, focuses on procedures and proven petroleum exploration techniques that are critical for generating viable prospects. Structural traps american association of petroleum. The traps could be stratigraphic or structural and many traps in niger delta basin are mostly structural. It also describes the major structural and stratigraphic types of traps and provides suggestions for trap evaluation. Therefore they are independent of structural or fault closure structural traps. Exploring for stratigraphic traps schlumberger mafiadoc. Carbon dioxide dissolution in structural and stratigraphic. For a more indepth description of the overall structure of oil and gas deposits, see oil and gas reservoir. Structural trap stratigraphic trap hydrodynamics trap combination trap.
Hydrocarbon traps that result from changes in rock type or pinchouts, unconformities, or. The geologic sequestration of carbon dioxide co 2 in structural and stratigraphic traps is a viable option to reduce anthropogenic emissions. Orc automates the complexity normally associated with volumetric analysis by using highly optimised algorithms, allowing the. Most of the undiscovered resources are expected in stratigraphic and combination traps.
Hydrocarbons migrate upward from their source through porous subterranean strata until their. I remember those days when you use to take a bunch of paper. Diagrams of structural and stratigraphic traps a trap is a geologic structure or a stratigraphic feature capable of retaining hydrocarbons. A variety of sealed geologic structure capable of retaining hydrocarbons, such as a fault or a fold. There can be a close genetic relation between contractional structural traps so that one type e.
Structural traps are post or syndepositional deformation or displacement of reservoirs andor seals. No matter if you are looking for structural traps, stratigraphic traps or looking at one of the unconventional shale plays it all starts out looking at a well log. Impact of structural setting on hydrocarbon trapping. Structural and stratigraphic traps are well established in geological literature. Stratigraphic traps were first identified in pennsylvania in 1880, but exploring for them remained a mystery until the mid1930s, when seismology began to be applied in the petroleum industry. Structural traps are the most important type of trap as they represent the majority of the worlds discovered petroleum resources. This chapter covers what we consider to be two critical components of a trap. Historically, stratigraphic traps have been perceived to be more risky than structural traps. 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. Stratigraphic traps, prevalent on the central basin platform, are.
The goal of oil and gas exploration is to identify and delineate structural traps suitable for profitably. Learn critical techniques for generating viable prospects. Traps are described as structural traps in deformed strata such as folds and faults or stratigraphic traps in areas where rock types change, such as unconformities, pinchouts and reefs. The expression of stratigraphic and combination traps in upper miocene stevens turbidite sandstones of the bakersfield arch, southern san joaquin valley, california, can be placed within a depositional sequence framework by integrating seismic, wirelinelog, and core data. In structural traps, 37 this geometry is due to either a largescale fold in the reservoir or the intersection of. In contrast, the driving forces for unconventional tight accumulations are forces of. Folds, faults, thrusts, fractures stratigraphic traps have specific configurations of reservoir andor seals. The northern onshore and offshore parts of the basin are. Many workers evaluated the structural analysis of niger delta basin using seismic data, in order to identify the stratigraphy, geological structures and traps with hydrocarbon accumulation tendencies.
Subsequent burial caused deep stratigraphic traps to become overmature, cracking oil to gas, and some new generation to begin progressively higher in the section. Because tectonics ultimately control deposition and erosion, however, few stratigraphic traps read more. Stratigraphic plays such as pinchouts, unconformities, sand lenses and channels are also suspected. Structural disruption of the traps in the early tertiary is hypothesized to have released sequestered hydrocarbons and caused remigration into newly formed structural traps. Many systems have been proposed for the classification of traps. Stratigraphic traps form where changes in rock type can retain hydrocarbons. Interpreting information from wells logs has gotten both easier and harder at the same time.
Well interpretation structural and stratigraphic mapping. A second major class of petroleum traps is the stratigraphic trap. There are two major categories of traps, and are classified based on how the petroleum accumulates. Two types of petroleum traps are structural and stratigraphic.
Structural traps, in contrast, consist of geologic structures in deformed strata such as faults and. Success of structural stratigraphic combination trap. Stratigraphic trap a second major class of oil traps is the stratigraphic trap. We elaborate on different types of petroleum traps such as structural, salt related, and stratigraphic traps. Structural traps are formed by deformation of reservoir rock, such as by folding or.
Petroleum is the general term used for all the natural hydrocarbons found in rocks. While dissolution of the co 2 stored in these traps reduces the longterm leakage risk, the dissolution process remains poorly understood in systems that reflect the appropriate subsurface geometry. Stratigraphic traps are hydrocarbon accumulations independent of structural or fault closure. Dalam keilmuan geology terutama dibidang keilmuan yang lebih specific yaitu geofisika, perpaduan antara ilmu geology dan ilmu fisika terapan. Structural and stratigraphic elements 79 eastern cuba 1 northern oriente area. Trapping is by a combination of both structural and stratigraphic mechanisms. Traps are usually classified according to the mechanism that produces the hydrocarbon accumulation. Oct 14, 2015 hydrocarbon traps that result from changes in rock type or pinchouts, unconformities, or other sedimentary features such as reefs or buildups are called stratigraphic traps. Exploring for oil and gas traps geoscienceworld books. The american association of petroleum geologists is an international organization with over 38,000 members in 100plus countries.
The north sinai district has a good oil exploration potential. Stratigraphic and structural relations of the birdbear. Stratigraphic traps american association of petroleum. Petroleum geology and resources of the west siberian basin. Hydrocarbon traps that result from changes in rock type or pinchouts, unconformities, or other sedimentary features such as reefs or buildups are called stratigraphic traps. Modern seismic attributes transforms classical structural. 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.
Though memoir 21 was first published in 1974, the concepts and illustrations are timeless for those interested in stratigraphic exploration for sandstone reservoirs. 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. In structural traps, 37 this geometry is due to either a largescale fold in. Stratigraphic traps are formed by deposition of reservoir rock, such as river channel or reef, or by erosion of. Structural and stratigraphic mapping of delta field, agbada formation, offshore niger delta, nigeria.
We have subdivided struc tural traps into fold traps, traps associated with faults, traps associated with piercement features. May 24, 2017 introduction migration of petroleum petroleum traps structural traps stratigraphic traps combination traps timing of trap formation conclusion references 3. Structural stratigraphic trap east kalimantan, indonesia alabama oil field. This is very similar to the central camaguey area and consists mostly of ultrabasics and cretaceous volcanics, with the ex ceptionofanarea ofmassive carbonateexposures north and west of gibara. Structural trap is a type of geological trap that forms as a result of. Domes, anticlines, and folds are common structures. Structural traps combination traps stratigraphic traps fig. Difference between structural and stratigraphic trap answers. Structural and stratigraphic mapping of delta field.
Traps are structural, stratigraphic, or a combination of the two. The most common type of structural trap is formed by an anticline, a structure with a concave as viewed from below roof caused by the local deformation of the reservoir rock and the impermeable cap rock. Quickly the reader will note the same relationships in sequence stratigraphy recognized by the author. Stratigraphic trap definition and meaning collins english. Stratigraphic traps have commonly a structural dips structural traps, in contrast, consist of geologic structures in deformed strata such as faults and folds whose geometries permit retention of hydrocarbons. The total petroleum system was asssessed as a single assessment unit. Tanezzuftghadames structuralstratigraphic assessment unit. This study analyses 271 exploration wells worldwide that targeted stratigraphic traps in clastic reservoirs since 2008, to investigate if this perception is justified. Di dunia migas istilah seismic bukan hal baru bagi kebanyakan professional engineer yang berkecimpung di. Hydrocarbon traps that form in geologic structures such as folds and faults are called structural traps.
Study questions predrill risks associated with stratigraphic. As of end 2003, 82% of the oil and gas fields and discoveries on the ukcs have been found in structural traps. Such traps can be found in clinoforms, in a pinchingout sedimentary structure, under an unconformity or in a structure created by the creep of an evaporite. The integration of seismic data with well logs greatly improved the extent of accuracy and exactness of structural and stratigraphic mapping in predicting lateral and vertical. Carbon dioxide dissolution in structural and stratigraphic traps. Stratigraphic traps are formed by deposition of reservoir rock, such as river channel or reef, or by erosion of reservoir rock, such as. The two main groups are structural traps and stratigraphic traps. Subsequent burial caused deep stratigraphic traps to become overmature, cracking oil to gas,and some new generation to begin progressively higher in the section.
Structural traps still preferred despite the key learning gained from evaluating global analogues, and the remaining upside in the exploration for stratigraphic and subtle combination traps, structural traps remain the preferred target, says robert. Structural traps in a complex compressional terrain. Major recent discoveries like buzzard, an upper jurassic stratigraphic pinchoutdip trap, are obvious analogues for future synrift targets, but these require the development of a strong conceptual model. Introduction migration of petroleum petroleum traps structural traps stratigraphic traps combination traps timing of trap formation conclusion references 3. Tanezzuftghadames structuralstratigraphic assessment. Traps with two or more trapping elements are called combination traps.
It is related to sediment deposition or erosion and is bounded on one or more sides by zones of low permeability. In contrast, the driving forces for unconventional tight accumulations are forces of expulsion which are produced by high pressures. This is a howto encyclopedia of prospecting for oil and gas. A variety of sealed geologic container capable of retaining hydrocarbons, formed by changes in rock type or pinchouts, unconformities, or sedimentary features such as reefs. A trap is an essential component of a petroleum system. Structural traps are anticlines, fault blocks, and domes. Structural and stratigraphic mapping of delta field, agbada. Stratigraphic traps made headlines in 2017 with the discovery of an estimated 1 billion boe of recoverable resources in the stabroek block offshore guyana within the payara, snoek, and turbot. What is the difference between stratigraphic traps and. Stratigraphic traps occurs when the hydrocarbon accumulated due to the change of rock.
Sometimes the distinction whether the trap belongs to one system or another is quite blurred. The purposes of this association are to advance the science of geology. Structural, stratigraphic and combination traps are encountered in the study area. A stratigraphic trap is a rock formation that contains hydrocarbons and is sealed by. Subsurface geology maps and crosssections visualization evaluation pe 4553 class february 6, 2008. While dissolution of the co 2 stored in these traps reduces the longterm leakage risk, the dissolution. The driving forces for conventional accumulations structural or stratigraphic traps are forces of buoyancy which are due to differences in densities of hydrocarbons and water. In a stratigraphic trap, the geometry allowing the accumulation of hydrocarbons is of sedimentary origin and has not undergone any tectonic deformation. Dolson cochaired an amoco symposium on stratigraphic trap exploration in 1989 and the cairo 98 aapg hedberg conference integrated structural and. Pdf structural and stratigraphic interpretations seismic.
Although simple, it includes a place for most kinds of traps known to contain oil and gas in commercial quantities. Tanezzuftghadames structuralstratigraphic assessment unit 20540301 triasghadames basin geologic province 2054 5 10 35 30 algeria tunisia libya m e d ite rra n e a n s e a sfax 0 250 500kilometers tanezzuftghadames structuralstratigraphic assessment unit 20540301 2056. Pdf structural, stratigraphic and combination traps on. The classification divides the traps broadly into three basic types. It is not allinclusive, but the exceptions will be pointed out as they occur. Because tectonics ultimately control deposition and erosion, however, few stratigraphic traps are completely without structural influence. The structure and hydrocarbon traps of sedimentary basins. Structural, stratigraphic and combination traps on outcropping lithostratigraphic units of the anambra basin, southeast nigeria article pdf available in petroleum and coal 621. In structural traps, this geometry is due to either a largescale fold in the reservoir or the. Fault related features also may be classified as structural traps if closure is present. Structural traps may have a stratigraphic component or vice versa.