scholarly journals Analysis of subsurface structural trend and stratigraphic architecture using 2D seismic data: a case study from Bannu Basin, Pakistan

2021 ◽  
Vol 11 (3) ◽  
pp. 1019-1036
Author(s):  
Kashif Ishaq ◽  
Sohail Wahid ◽  
Muhammad Yaseen ◽  
Muhammad Hanif ◽  
Shehzad Ali ◽  
...  
Keyword(s):  
Rock Physics ◽  
Seismic Profile ◽  
Poor Quality ◽  
Hydrocarbon Exploration ◽  
Lower Permian ◽  
Seismic Profiles ◽  
Contour Maps ◽  
Depth Contour ◽  
Datta Formation ◽  
Exploratory Wells

AbstractThe present study is focused on the subsurface geology of Bannu Basin, a part of western Indus foreland Pakistan. For this purpose, some regional seismic profiles and deep exploratory wells data have been used in integration.A total of ten mappabale seismic reflection events have been identifed which are representative of specific geological units. In general, based on the seismic the formation trends, the horizons are dipping in the northwest direction of the study area. The area generally deepens toward the northwest due to sediments load toward the northwest. The seismic profile MWI-83 shows a unique faults bounded anticlinal structure that has also been mapped on the two-dimmensional contour maps. This could be regarded as potential hydrocarbon entrapment. The regional seismic profiles are contoured for the entire grid in both time and depth domain to obtain the clearer image of the subsurface individual stratigraphic units. The 2D contour maps for Lower Permian aged Warcha Sandstone, Middle Triassic aged Tredian Formation and Early Jurrasic aged Datta Formation have been prepared using gridded TWT of the seismic profiles. The time and depth contour maps of the Datta Formation and Tredian Formation show a four way clouser oriented in the southeast dierction. The area of the closure was computed which is 24 Sq km approximately. Furthermore, the formation tops of the five wells have been used to correlate the wells for understanding the lateral and vertical variations in the stratigraphic layers. The correlation shows that the Datta Formation’s thickness increases at the centre of the basin whereas decreases on the east and south flanks of the basin. Reasons of Wells failure were concluded on the basis of the final well report and concluded that these well failure occur due to poor quality of the data and also due to some mechanical problems. Reservoircharacterization using statistical rock physics and petrophysics coupled with core data analysis can provide further insights into the hydrocarbon exploration.

scholarly journals Comparison between reprocessed seismic profiles: Seismologic and geologic data — A case study of the Colfiorito earthquake area

Geophysics ◽  
2006 ◽  
Vol 71 (2) ◽  
pp. B29-B40 ◽  
Author(s):  
Eusebio Stucchi ◽  
Francesco Mirabella ◽  
Maria Grazia Ciaccio
Keyword(s):  
Seismic Profile ◽  
Hydrocarbon Exploration ◽  
Normal Faults ◽  
Seismic Profiles ◽  
Epicentral Area ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Marche Region ◽  
History Of

Seismic reflection data are used to reconstruct the subsurface geologic structures below the Umbria-Marche region in Italy, a highly seismogenic area with a recent history of seismic activity (the 1997–1998 Colfiorito sequence). We reprocess three vibroseis seismic profiles (acquired in the early 1980s for hydrocarbon exploration) whose stacked sections were optimized for relatively deep oil targets. On the reprocessed seismic profile closest to the epicentral area, we construct the main reflectors to a depth of about 4 s (two-way time) and compare this interpretation with the available hypocenters of the 1997 earthquakes. The improvements in visualizing the shallow and deep reflections provide a better correlation between the reflectors and the observed surface structures as well as a better delineation of the basement-rock geometry. We find that part of the Colfiorito sequence is localized around some of the reflectors in the reflection profile, which we interpret as related to the active normal faults that outcrop at the surface.

scholarly journals Comparison of Quantitative Morphology of Layered and Arbitrary Patterns: Contrary to Visual Perception, Binary Arbitrary Patterns Are Layered from a Structural Point of View

2021 ◽  
Vol 11 (14) ◽  
pp. 6300
Author(s):  
Igor Smolyar ◽  
Daniel Smolyar
Keyword(s):  
Boolean Function ◽  
Layer Structure ◽  
Central Element ◽  
Morphological Characteristics ◽  
Building Blocks ◽  
Point Of View ◽  
Living Systems ◽  
Seismic Profiles ◽  
Contour Maps ◽  
Anisotropic Layers

Patterns found among both living systems, such as fish scales, bones, and tree rings, and non-living systems, such as terrestrial and extraterrestrial dunes, microstructures of alloys, and geological seismic profiles, are comprised of anisotropic layers of different thicknesses and lengths. These layered patterns form a record of internal and external factors that regulate pattern formation in their various systems, making it potentially possible to recognize events in the formation history of these systems. In our previous work, we developed an empirical model (EM) of anisotropic layered patterns using an N-partite graph, denoted as G(N), and a Boolean function to formalize the layer structure. The concept of isotropic and anisotropic layers was presented and described in terms of the G(N) and Boolean function. The central element of the present work is the justification that arbitrary binary patterns are made up of such layers. It has been shown that within the frame of the proposed model, it is the isotropic and anisotropic layers themselves that are the building blocks of binary layered and arbitrary patterns; pixels play no role. This is why the EM can be used to describe the morphological characteristics of such patterns. We present the parameters disorder of layer structure, disorder of layer size, and pattern complexity to describe the degree of deviation of the structure and size of an arbitrary anisotropic pattern being studied from the structure and size of a layered isotropic analog. Experiments with arbitrary patterns, such as regular geometric figures, convex and concave polygons, contour maps, the shape of island coastlines, river meanders, historic texts, and artistic drawings are presented to illustrate the spectrum of problems that it may be possible to solve by applying the EM. The differences and similarities between the proposed and existing morphological characteristics of patterns has been discussed, as well as the pros and cons of the suggested method.

THE VALUE OF INTEGRATING BOREHOLE RESISTIVITY IMAGES WITH GEOLOGICAL DATA: RELEVANCE TO HYDROCARBON EXPLORATION

1997 ◽  
Vol 37 (1) ◽  
pp. 301 ◽  
Author(s):  
B. E. J. Messent ◽  
C.M. Yacopetti
Keyword(s):  
Poor Quality ◽  
Depositional Environments ◽  
Hydrocarbon Exploration ◽  
Qualitative Assessment ◽  
Low Permeability ◽  
Geological Data ◽  
Close Proximity ◽  
Potential Reservoir ◽  
Low Permeability Reservoirs ◽  
Selection Of

This paper outlines the contribution borehole resistivity images can make in a frontier exploration program when they are integrated with all available geological data. Specific examples are given from the Duntroon Basin.Dipmeter data and borehole resistivity images can be used to validate seismic structural interpretations. An example is given to show the comparison in interpretation of the different methods.Faults are identified on the borehole images and in addition, qualitative assessment of sealing potential can be made by determining the occurrence and extent of mineralisation. In Greenly-1 the hydrocarbon shows, which are interpreted as migrated hydrocarbons, are found In close proximity to faults identified on borehole images. It is postulated that the faults acted as a conduit for the migrating hydrocarbons. However, these fault planes are now mineralised and interpreted to be sealing. This interpretation is supported by the presence of isolated, over-pressured sandstones.Resistivity images readily identify the orientation of present day horizontal stresses with its implications for fault-trap integrity. However, this is not deemed to be an issue in the Duntroon Basin as there is evidence that at least some of the faults are sealing. Borehole images can also be used to assess caprock integrity by determining the presence or absence of fractures.Within potential reservoir units, borehole resistivity images assist in the interpretation of depositional environments, reservoir geometries and post-depositional changes which affect reservoir quality.Borehole resistivity images provide qualitative interpretations of permeability. It is therefore possible to use the images in the selection of pre-test seats and sampling points in poor quality boreholes or low permeability reservoirs.

Lower Permian Carbonate Buildups in the Northern Timan–Pechora Basin as the Main Hydrocarbon Exploration Object

2020 ◽  
Vol 55 (4) ◽  
pp. 245-260
Author(s):  
V. A. Zhemchugova ◽  
N. V. Evdokimov ◽  
J. Poort ◽  
G. G. Akhmanov
Keyword(s):  
Hydrocarbon Exploration ◽  
Lower Permian ◽  
Pechora Basin ◽  
Carbonate Buildups

GEOPHYSICAL HISTORY OF PARENTIS OIL FIELD, FRANCE

Geophysics ◽  
1956 ◽  
Vol 21 (3) ◽  
pp. 815-827 ◽  
Author(s):  
Raoul Vajk ◽  
George Walton
Keyword(s):  
Cross Sections ◽  
Gravity Anomalies ◽  
Oil Field ◽  
Seismic Profiles ◽  
Contour Maps ◽  
History Of ◽  
Standard Oil Company ◽  
Aquitaine Basin ◽  
Surface Geology ◽  
Gravity Map

In 1951, the French Government granted an exclusive exploration permit to the Esso R.E.P. (a Standard Oil Company affiliate) over an area of 4,357,980 acres around Bordeaux in the northern part of the Aquitaine Basin, France. This area was investigated first by surface geology; then it was surveyed by the gravity meter. In checking the gravity anomalies by the reflection seismograph, a subsurface structure was found at Parentis in 1953, which was drilled in 1954, and was proved to be oil bearing. The Parentis oil field is the most important oil field, not only in France, but in all Europe outside the Iron Curtain. Gravity map, seismograph map, seismic profiles, telluric map and geological contour maps, and cross sections of the Parentis structure are presented.

Quantifying hydraulically induced fracture height and density from rapid time-lapse DAS VSP

Geophysics ◽  
2020 ◽  
pp. 1-26
Author(s):  
Xiaomin Zhao ◽  
Mark E. Willis ◽  
Tanya Inks ◽  
Glenn A. Wilson
Keyword(s):  
Rock Physics ◽  
Horizontal Wells ◽  
Time Lapse ◽  
Seismic Profile ◽  
P Wave ◽  
Fracture Properties ◽  
Vsp Data ◽  
Rock Physics Modeling ◽  
Physics Modeling ◽  
Fracture Height

Several recent studies have advanced the use of time-lapse distributed acoustic sensing (DAS) vertical seismic profile (VSP) data in horizontal wells for determining hydraulically stimulated fracture properties. Hydraulic fracturing in a horizontal well typically generates vertical fractures in the rock medium around each stage. We model the hydraulically stimulated formation with vertical fracture sets about the lateral wellbore as a horizontally transverse isotropic (HTI) medium. Rock physics modeling is used to relate the anisotropy parameters to fracture properties. This modeling was used to develop an inversion for P-wave time delay to fracture height and density of each stage. Field data from two horizontal wells were analyzed, and fracture height evaluated using this technique agreed with microseismic analysis.

Traveltime inversion of offset vertical seismic profiles—A feasibility study

Geophysics ◽  
1984 ◽  
Vol 49 (3) ◽  
pp. 250-264 ◽  
Author(s):  
L. R. Lines ◽  
A. Bourgeois ◽  
J. D. Covey
Keyword(s):  
Inverse Method ◽  
Synthetic Data ◽  
Real Data ◽  
Seismic Profile ◽  
Inversion Method ◽  
Earth Model ◽  
Seismic Profiles ◽  
Traveltime Inversion ◽  
Vertical Seismic Profiles ◽  
Inversion Techniques

Traveltimes from an offset vertical seismic profile (VSP) are used to estimate subsurface two‐dimensional dip by applying an iterative least‐squares inverse method. Tests on synthetic data demonstrate that inversion techniques are capable of estimating dips in the vicinity of a wellbore by using the traveltimes of the direct arrivals and the primary reflections. The inversion method involves a “layer stripping” approach in which the dips of the shallow layers are estimated before proceeding to estimate deeper dips. Examples demonstrate that the primary reflections become essential whenever the ratio of source offset to layer depth becomes small. Traveltime inversion also requires careful estimation of layer velocities and proper statics corrections. Aside from these difficulties and the ubiquitous nonuniqueness problem, the VSP traveltime inversion was able to produce a valid earth model for tests on a real data case.

Estimation of the discrete Fourier transform, a linear inversion approach

Geophysics ◽  
1996 ◽  
Vol 61 (4) ◽  
pp. 1128-1136 ◽  
Author(s):  
Mauricio D. Sacchi ◽  
Tadeusz J. Ulrych
Keyword(s):  
Fourier Transform ◽  
Array Processing ◽  
Broad Band ◽  
Temporal Analysis ◽  
Seismic Profile ◽  
Spectral Signature ◽  
Seismic Profiles ◽  
Linear Inversion ◽  
Spatial Coverage ◽  
Spatio Temporal

Spatio‐temporal analysis of seismic records is of particular relevance in many geophysical applications, e.g., vertical seismic profiles, plane‐wave slowness estimation in seismographic array processing and in sonar array processing. The goal is to estimate from a limited number of receivers the 2-D spectral signature of a group of events that are recorded on a linear array of receivers. When the spatial coverage of the array is small, conventional f-k analysis based on Fourier transform leads to f-k panels that are dominated by sidelobes. An algorithm that uses a Bayesian approach to design an artifacts‐reduced Fourier transform has been developed to overcome this shortcoming. A by‐product of the method is a high‐resolution periodogram. This extrapolation gives the periodogram that would have been recorded with a longer array of receivers if the data were a limited superposition of monochromatic planes waves. The technique is useful in array processing for two reasons. First, it provides spatial extrapolation of the array (subject to the above data assumption) and second, missing receivers within and outside the aperture are treated as unknowns rather than as zeros. The performance of the technique is illustrated with synthetic examples for both broad‐band and narrow‐band data. Finally, the applicability of the procedure is assessed analyzing the f-k spectral signature of a vertical seismic profile (VSP).

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