Stratigraphic traps american association of petroleum. 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. Onlap valley fill channels onlaps stratigraphic traps meandering stream fluvial environments rivers braided stream meandering stream sandstone mudstone 3d seismic slice fluvial meander at 2. This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. Structural traps successful exploration starts here. Sequence stratigraphy as a concrete stratigraphic discipline abstract sequence stratigraphy is a stratigraphic discipline in which stratigraphic surfaces that represent changes in depositional trend are used for correlation and for defining specific types of sequence stratigraphic units.
The cross section documents stratigraphic relationships previously unreported and contrasts with earlier interpretations in two ways. The deliberate search for the stratigraphic trap download. Other articles where stratigraphic trap is discussed. Houseknecht, electronic resource represents a specific, individual, material embodiment of a distinct intellectual or artistic creation found in indiana state library. Stratigraphic trap article about stratigraphic trap by the. We have subdivided struc tural traps into fold traps, traps associated with faults, traps associated with piercement features. Reconnaissance of their expected locations, depth, and geometry was the main task of the paper. For example, a dipping reservoir may pinch out between two layers of.
Beaufortian stratigraphic plays in the national petroleum reserve alaska npra. Large stratigraphic traps are most common in basins with gentle structural dip, where small hydrocarbon columns can be areally extensive. Stratigraphic traps had low finding costs overall at c. Study of a stratigraphic trap of paleocenelate cretaceous. Sequence stratigraphy combines the strengths of seismic stratigraphy with litho and biostratigraphy to enhance the effectiveness of stratigraphic trap exploration. Stratigraphic traps have commonly a structural dips stratigraphic traps, it is likely that only heavy hc might be discovered as the seals cannot contain the light fraction of hc.
Stratigraphic trap article about stratigraphic trap by. Stratigraphic and subtle combination traps are those which cannot be defined by structural closure alone. Stratigraphic traps, prevalent on the central basin platform, are. The second edition of the aapg stratigraphic traps of the middle east workshop took place on 11 december 2017 at the shangrila barr al jissah hotel, muscat, oman. Exploring for oil and gas traps geoscienceworld books. Stratigraphic traps are those traps whose geometry is formed by changes in lithology. The item beaufortian stratigraphic plays in the national petroleum reservealaska npra, david w. This collection of papers examine a number of themes related to exploration for stratigraphic traps, ranging from play and risk assessment, through regional assessments of stratigraphic trapping potential, specific exploration programmes targeted. Historically, stratigraphic traps have been perceived to be more risky than structural traps. A second major class of oil traps is the stratigraphic trap. Beaufortian stratigraphic plays in the national petroleum.
Sequence stratigraphy as a sequence stratigraphy as a. This one took me longer to create as i found a few sources which had slightly different information to sift through. Petroleum reservoirs are broadly classified as conventional and unconventional reservoirs. Search for the subtle trap download ebook pdf, epub, tuebl. Discussions and examples show how to use sequence stratigraphy to integrate seismic and geologic data. A stratigraphic trap holds the oil because of a decrease in permeability of the subsurface beds. Many other such reservoirs are waiting to be located by the drill. 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. Because tectonics ultimately control deposition and erosion, however, few stratigraphic traps are completely without structural influence. Exploring for stratigraphic traps exploring for oil and gas. Structural and stratigraphic traps are well established in geological literature. 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. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower.
Stratigraphic trap definition and meaning collins english. Learn critical techniques for generating viable prospects. This is a howto encyclopedia of prospecting for oil and gas. Analyze seal, reservoir, and show to find and evaluate traps. The new structure, which has been mapped with twodimensional seismic, covers a twentyfivesquaremile area and is a structural rather than a stratigraphic trap, which means gasbearing reservoir sands would likely be thicker and more productive than thinner layers of reservoir more likely in a stratigraphic trap. 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. A petroleum reservoir or oil and gas reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. Exploring for stratigraphic traps schlumberger limited. There are two main prospect of finding stratigraphic traps, one is in the sand fill lowstand incised valley and another is in regressive highstand sand that truncated against shalefilled channel. Stratigraphic traps do not appear to be inherently riskier, although success in these plays relies on using the right geoscience tools and ensuring. It is related to sediment deposition or erosion and is bounded on one or more sides by zones of low permeability. Stratigraphic traps have commonly a structural dips pdf, epub, mobi total read.
Stratigraphic traps of pinchout type may perform prolific petroleum locations in iraq. Pdf historically, stratigraphic traps have been perceived to be. This year we had seventy two attendees from ten different countries. Digital tabulation of stratigraphic data from oil and gas wells in the santa maria basin and surrounding areas, central california coast by donald s. Stratigraphic trap definition of stratigraphic trap by.
Structural traps, in contrast, consist of geologic structures in deformed strata such as faults and folds whose geometries permit retention of hydrocarbons. 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. Stratigraphic trap definition is a natural reservoir in which oil or gas may be confined because of changes in porosity and permeability of the strata rather than as. Several avenues are available for members of the uva community needing library resources, including hathitrusts newlyreleased trove of ed digital material, open educational resources, online journals, databases, and ebooks. Reconnaissance of their expected locations, depth, and. Shumaker abstract stratigraphic information from 694 oil and gas exploration wells from the onshore santa maria basin and. 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. Capillary pressures in stratigraphic traps authors.
Diagrams of structural and stratigraphic traps a trap is a geologic structure or a stratigraphic feature capable of retaining hydrocarbons. Trapping is by a combination of both structural and stratigraphic mechanisms. Success rates and finding costs can match or better structural traps in some areas, especially for gas plays. Figure 2 illustrates in map view how dip rate affects stratigraphic trap size. Stratigraphic traps have commonly a structural dips stratigraphic traps of pinchout type may perform prolific petroleum locations in iraq. Structural and stratigraphic traps are attractive sites for co2 sequestration. Stratigraphic trap a second major class of oil traps is the stratigraphic trap. In contrast, the driving forces for unconventional tight accumulations are forces of expulsion which are produced by high pressures. The geologic sequestration of carbon dioxide co 2 in structural and stratigraphic traps is a viable option to reduce anthropogenic emissions.
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. Structural traps combination traps stratigraphic traps fig. Capillary pressures between oil and water in rock pores are responsible for trapping oil, and the height of oil column, z o, in a reservoir may be calculated from the hobson equation modified as follows. The prediction of trap capacity for stratigraphic traps must consider both the seal capacity of the rocks above and below the reservoir and the seal capacity of lateral rocks. In a stratigraphic trap, variations within the rock strata themselves e. Today, fully 40% of the oil found in mature hydrocarbon provinces is being found in stratigraphic traps. In stratigraphic traps, the concavedown shape is due to changes in rock type. For an update on activity of hurricane exploration please see the link at the end of this article. Click download or read online button to get search for the subtle trap book now. This study analyses 271 exploration wells worldwide that targeted stratigraphic traps in clastic reservoirs since 2008, to investigate if this perception is justified. This file is licensed under the creative commons attributionshare alike 3. Jan 07, 2004 the item beaufortian stratigraphic plays in the national petroleum reservealaska npra, david w.
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. Pdf stratigraphic traps of pinchout type may perform prolific petroleum locations in iraq. Stratigraphic traps are created by any variation in the stratigraphy that is independent of structural deformation, although many stratigraphic traps involve a tectonic component such as tilting of strata. The premise is that effective stratigraphic trap exploration consists of the following steps. Two main groups can be recognized primary stratigraphic traps result from variations in facies that developed during sedimentation. Structural trap is a type of geological trap that forms as a result of. The 8th conference on the petroleum geology of nw europe was held in september 2015 and marked. As structural dip steepens, the need for highquality seals increases, raising the probability of trap failure. Digital tabulation of stratigraphic data from oil and gas.
Exploring for stratigraphic traps exploring for oil and. Search for the subtle trap download ebook pdf, epub. As there are different types of stratigraphic traps, understanding of the stratigraphy is. Lexington field is located in northeastern clark county, kansas, principally in secs. We wont have a chance to do that until the field trip, later in the. Notice the common co occurrence of arching and faulting. In a stratigraphic trap, the geometry allowing the accumulation of hydrocarbons is of sedimentary origin and has not undergone any tectonic deformation. Chapter 21 exploring for stratigraphic traps by john c. This site is like a library, use search box in the widget to get ebook that you want. Please check out my latest geoscience instructional video. Structural traps are anticlines, fault blocks, and domes.
What is the difference between stratigraphic traps and. This collection of papers examine a number of themes related to exploration for stratigraphic traps, ranging from play and risk assessment, through regional assessments of stratigraphic trapping potential, specific exploration. Paleontological research institution and its museum of the earth schlumberger. Carbon dioxide dissolution in structural and stratigraphic traps. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. Seismic expression of a subtle stratigraphic trap, lexington field, clark county, kansas larry j. Structural plays in ellesmerian sequence and correlative strata of the national petroleum reserve, alaska by thomas e. Pdf locating of promising stratigraphic traps of pinchout type in. Exploring for stratigraphic traps schlumberger mafiadoc. Allan et al, 2006 all facts and figures true on date of original publication.
A stratigraphic trap is a rock formation that contains hydrocarbons and is sealed by. Hydrodynamic traps occur where the downward movement of water prevents. Geological survey editorial standards or with the north american stratigraphic code. Published by the geological society on behalf of pgc ltd. One of the more difficult tasks in categorizing an oil or gas accumulation into a. Pdf locating of promising stratigraphic traps of pinch.
1417 1032 1285 151 186 240 1352 1081 996 936 94 387 600 1581 959 201 1185 807 1327 1575 475 306 263 188 860 279 106 1072 667 42 418 1372 709 580 745 196 900 1137 906 456 507 54 991 1336