Use of Computer Workstations in the Study of Environmental Geology: Integration of Shallow Reflection Seismic, V.S.P., and Well Data: ABSTRACT

Abstract. The concept of structural inversion was introduced in the early 1980s. By definition, an inversion structure forms when a pre-existing extensional (or transtensional) fault controlling a hangingwall basin containing a syn-rift or passive fill sequence subsequently undergoes compression (or transpression) producing partial (or total) extrusion of the basin fill. Inverted structures provide traps for petroleum exploration, typically four-way structural closures. As to the degree of inversion, based on large number of worldwide examples seen in various basins, the most preferred petroleum exploration targets are mild to moderate inversional structures, defined by the location of the null-points. In these instances, the closures have a relatively small vertical amplitude, but simple in a map-view sense and well imaged on seismic reflection data. Also, the closures typically cluster above the extensional depocentres which tend to contain source rocks providing petroleum charge during and after the inversion. Cases for strong or total inversion are generally not that common and typically are not considered as ideal exploration prospects, mostly due to breaching and seismic imaging challenges associated with the trap(s) formed early on in the process of inversion. Also, migration may become tortuous due to the structural complexity or the source rock units may be uplifted above the hydrocarbon generation window effectively terminating the charge once the inversion occurred. For any particular structure the evidence for inversion is typically provided by subsurface data sets such as reflection seismic and well data. However, in many cases the deeper segments of the structure are either poorly imaged by the seismic data and/or have not been penetrated by exploration wells. In these cases the interpretation of any given structure in terms of inversion has to rely on the regional understanding of the basin evolution with evidence for an early phase of substantial crustal extension by normal faulting.

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A multidisciplinary study of the Palaeogene succession offshore southern West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v191.5134 ◽

2002 ◽

pp. 90-96

Author(s):

Finn Dalhoff ◽

James A. Chalmers ◽

Henrik Nøhr-Hansen ◽

Jan A. Rasmussen ◽

Emma Sheldon ◽

...

Keyword(s):

Seismic Data ◽

Seismic Stratigraphy ◽

Depositional Sequences ◽

Original Series ◽

West Greenland ◽

Dinoflagellate Cyst ◽

Reflection Seismic ◽

Multidisciplinary Study ◽

New Interpretation ◽

Well Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Dalhoff, F., Chalmers, J. A., Nøhr-Hansen, H., Rasmussen, J. A., Sheldon, E., & Gregersen, U. (2002). A multidisciplinary study of the Palaeogene succession offshore southern West Greenland. Geology of Greenland Survey Bulletin, 191, 90-96. https://doi.org/10.34194/ggub.v191.5134 _______________ A project with the aim of amalgamating an interpretation of reflection seismic data from offshore southern West Greenland with a new interpretation of well data was finalised at the Geological Survey of Denmark and Greenland (GEUS) in 2001 (Chalmers et al. 2001b). As part of this study, seismic and depositional sequences between major regional unconformities of Danian and mid-Eocene age were delineated and dated. New palaeoenvironmental and sedimentological interpretations using dinoflagellate cyst, microfossil and nannoplankton stratigraphies and palaeoenvironmental interpretations from the five exploration wells drilled offshore West Greenland in the 1970s have been combined with a revised interpretation of lithology and correlated with the aid of seismic stratigraphy. The Qulleq-1 well drilled in 2000 was relinquished late in the project period (Christiansen et al. 2002, this volume), and it has therefore only been possible to incorporate biostratigraphic information from this well into the project.

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Time-Depth Curve Evaluation Method for Conversion Time to Depth at Penobscot Field, Nova-Scotia, Canada

Jurnal ILMU DASAR ◽

10.19184/jid.v17i1.2663 ◽

2017 ◽

Vol 17 (1) ◽

pp. 25

Author(s):

Fitri Rizqi Azizah ◽

Puguh Hiskiawan ◽

Sri Hartanto

Keyword(s):

Time Domain ◽

Seismic Data ◽

Evaluation Method ◽

Seismic Survey ◽

Seismic Exploration ◽

Reflection Seismic ◽

Conversion Time ◽

Well Data ◽

The Time Domain ◽

Depth Curve

Oil and natural gas as a fossil fuel that is essential for human civilization, and included in nonrenewable energy, making this energy source is not easy for updated availability. So that it is necessary for exploration and exploitation reliable implementation. Seismic exploration becomes the method most widely applied in the oil, in particular reflection seismic exploration. Data wells (depth domain) and seismic data (time domain) of reflection seismic survey provides information wellbore within the timescale. As for the good interpretation needed information about the state of the earth and is able to accurately describe the actual situation (scale depth). Conversion time domain into the depth domain into things that need to be done in generating qualified exploration map. Method of time-depth curve to be the method most preferred by the geophysical interpreter, in addition to a fairly short turnaround times, also do not require a large budget. Through data information check-shot consisting of the well data and seismic data, which is then exchanged plotted, forming a curve time-depth curve, has been able to produce a map domain depth fairly reliable based on the validation value obtained in the range of 54 - 176m difference compared to the time domain maps previously generated.Keywords: Energy nonrenewable, survei seismik, peta domain waktu, peta domain kedalaman, time-depth curve

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Crustal thickness under the Gulf of St. Lawrence, northern Appalachians, from gravity and deep seismic data

Canadian Journal of Earth Sciences ◽

10.1139/e89-130 ◽

1989 ◽

Vol 26 (8) ◽

pp. 1517-1532 ◽

Cited By ~ 36

Author(s):

F. Marillier ◽

J. Verhoef

Keyword(s):

Seismic Data ◽

Bouguer Anomaly ◽

Crustal Thickness ◽

Moho Depth ◽

Crustal Layer ◽

Reflection Seismic ◽

Middle Paleozoic ◽

Lateral Extent ◽

Well Data ◽

Lower Crustal

We have determined crustal thickness in the Gulf of St. Lawrence, an area that corresponds to an offset of the main northern Appalachians units. A "complete" Bouguer anomaly was calculated from recent depth-to-basement compilations and sediment densities from well data. The Moho surface was obtained by inverting the Bouguer anomaly, assuming a single density contrast at depth, and using an average depth provided by deep reflection seismic data. The resulting crustal model shows a Moho depth of 42–44 km beneath the Grenville Craton, north of the Appalachian deformation front. South of this front, the depth to Moho displays a pronounced thinning of the crust beneath the Carboniferous Magdalen Basin. This is in striking contrast to the deep seismic data, which give a Moho depth of about 43 km. The modelling of the Bouguer anomaly in the Magdalen Basin, taking into account the seismic reflection and refraction data, reconciles these different results and suggests that a 43 km deep Moho beneath the basin is associated with a lower crustal layer about 13 km thick, with high velocity (7.35 km/s) and density (3.05 g/cm3). The Bouguer anomaly suggests that the lateral extent of this high-density layer is confined roughly to the Magdalen Basin. We suggest that this layer is due to mantle underplating of the crust as a result of the Carboniferous-age formation of the Magdalen Basin, and that it is not a feature related to the early to middle Paleozoic development of the Appalachian Orogen.

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Sedimentary basin investigation using receiver function: an East African Rift case study

Geophysical Journal International ◽

10.1093/gji/ggy405 ◽

2018 ◽

Vol 215 (3) ◽

pp. 2105-2113 ◽

Cited By ~ 5

Author(s):

Nicola Piana Agostinetti ◽

Francesca Martini ◽

Joe Mongan

Keyword(s):

Sedimentary Basin ◽

Receiver Function ◽

Relevant Information ◽

Data Sets ◽

East African ◽

Reflection Seismic ◽

High Resolution Images ◽

African Rift ◽

Well Data

SUMMARY We apply receiver function (RF) methodology to map the geometry of a sedimentary basin along a ∼10-km-long profile of broadband seismometers that recorded continuously for approximately 3 months. For a subset of the stations, we apply the Neighbourhood Algorithm inversion scheme, to quantify the geometry of basin bounding fault directly beneath the stations. We compare our results with active reflection seismic data and with the lithostratigraphy from a well located along the profile. We find that the P-to-s conversions from the sediments–basement interface (SBI), recorded in RF data sets together with information on intrabasin structures, are useful for obtaining high resolution images of the basin. The depth of the SBI derived from RF inversion is consistent (within ∼0.4 km) with the estimates from active reflection seismic and the well data. This study highlights that analysis of teleseismic waveforms can retrieve relevant information on the structure of a sedimentary basin.

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Porosity from seismic data: A geostatistical approach

Geophysics ◽

10.1190/1.1442404 ◽

1988 ◽

Vol 53 (10) ◽

pp. 1263-1275 ◽

Cited By ~ 142

Author(s):

Philippe M. Doyen

Keyword(s):

Seismic Data ◽

Mean Square ◽

Least Squares Regression ◽

Reservoir Properties ◽

Reflection Seismic ◽

Geostatistical Approach ◽

Independent Observations ◽

Local Correlations ◽

Mapping Techniques ◽

Well Data

Using a geostatistical technique called cokriging, the areal distribution of porosity is estimated first in a numerically simulated reservoir model, then in an oil‐bearing channel‐sand of Alberta, Canada. The cokriging method consistently integrates 3-D reflection seismic data with well measurements of the porosity and provides error‐qualified, linear mean square estimates of this parameter. In contrast to traditional seismically assisted porosity mapping techniques that treat the data as spatially independent observations, the geostatistical approach uses spatial autocorrelation and crosscorrelation functions to model the lateral variations of the reservoir properties. In the simulated model, the experimental root‐mean square porosity error with cokriging is 50 percent smaller than the error in predictions relying on a least‐squares regression of porosity on seismically derived transit time in the reservoir interval. In the Alberta reservoir, a cross‐validation study at the wells demonstrates that the cokriging procedure is 20 percent more accurate, in a mean square sense, than a standard regression method, which accounts only for local correlations between porosity and seismically derived impedances. In both cases, cokriging capitalizes on areally dense seismic measurements that are indirectly related to porosity. As a result, when compared to estimates obtained by interpolating the well data, this technique considerably improves the spatial description of porosity in areas of sparse well control.

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Lateral migration of large sedimentary bodies in a deep-marine system offshore of Argentina

Scientific Reports ◽

10.1038/s41598-021-99730-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adam Kirby ◽

Francisco Javier Hernández-Molina ◽

Sara Rodrigues

Keyword(s):

Lateral Migration ◽

Bottom Currents ◽

Reflection Seismic ◽

Depositional System ◽

Show Evidence ◽

Marine System ◽

Well Data ◽

Stacking Patterns ◽

The Antarctic ◽

Seismic Images

AbstractContourite features are increasingly identified in seismic data, but the mechanisms controlling their evolution remain poorly understood. Using 2D multichannel reflection seismic and well data, this study describes large Oligocene- to middle Miocene-aged sedimentary bodies that show prominent lateral migration along the base of the Argentine slope. These form part of a contourite depositional system with four morphological elements: a plastered drift, a contourite channel, an asymmetric mounded drift, and an erosive surface. The features appear within four seismic units (SU1–SU4) bounded by discontinuities. Their sedimentary stacking patterns indicate three evolutionary stages: an onset stage (I) (~ 34–25 Ma), a growth stage (II) (~ 25–14 Ma), and (III) a burial stage (< 14 Ma). The system reveals that lateral migration of large sedimentary bodies is not only confined to shallow or littoral marine environments and demonstrates how bottom currents and secondary oceanographic processes influence contourite morphologies. Two cores of a single water mass, in this case, the Antarctic Bottom Water and its upper interface, may drive upslope migration of asymmetric mounded drifts. Seismic images also show evidence of recirculating bottom currents which have modulated the system’s evolution. Elucidation of these novel processes will enhance basin analysis and palaeoceanographic reconstructions.

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