Journal ArticleDOI
The prediction of high porosity chalks in the East Hod Field
Simon Campbell,N. Gravdal +1 more
Reads0
Chats0
TLDR
In this article, the East Hod Field in the Norwegian Block 2/11 produces from the Lower Tertiary and Upper Cretaceous Chalk Group and a good correlation between seismic impedance and porosity is observed.Abstract:
The East Hod Field in the Norwegian Block 2/11 produces from the Lower Tertiary and Upper Cretaceous Chalk Group. Although at first sight the trapping mechanism of the East Hod Field appears to be structural, increased understanding of porosity preservation, combined with new seismic interpretation, demonstrates that there is also a strong stratigraphic component. Both autochthonous and allochthonous facies occur, the latter forming the principal reservoirs. The extremely homogeneous nature of the matrix means that variations in seismic response directly reflect changes in pore volume, and a good correlation between seismic impedance and porosity is observed. High quality 3D seismic data made it possible to undertake seismic inversion which, together with the correlation between seismic impedance and porosity, allows prediction of porosity variations within the inter-well volume. The results indicate that within the allochthonous reservoir units, porosity is maintained in down-flank areas at depths previously believed to be predominantly tight. Seismic inversion is particularly accurate for predicting porosity because of the exceptionally uniform nature of the chalk matrix.read more
Citations
More filters
Book
Seismic Amplitude: An Interpreter's Handbook
Rob Simm,Mike Bacon +1 more
TL;DR: In this paper, the authors provide a complete framework for seismic amplitude interpretation and analysis in a practical manner that allows easy application independent of any commercial software products, and guide the interpreter through each step, introducing techniques with practical observations.
Book
3-D Seismic Interpretation
M. Bacon,R. Simm,T. Redshaw +2 more
TL;DR: In this paper, a 3D seismic data acquisition and processing is described, followed by structural interpretation and geologic interpretation, and finally inversion of seismic amplitudes and time-lapse seismic data visualization.
Journal ArticleDOI
Seismic interpretation of circular geological structures
TL;DR: In this paper, the authors present a set of geometrical and geological criteria for identifying circular structures in a 3D seismic interpretation, including salt/shale diapirs, salt withdrawal basins, polygonal fault blocks, dissolution collapse hollows, breccia pipes, calderas, gas pockmarks, bioherms, sand volcanoes, pull-aparts, impact craters and tectonic folds.
Book ChapterDOI
Hydrodynamic activity and tilted oil-water contacts in the North Sea
TL;DR: In this article, the authors used laboratory experiments and computer simulations to examine the response of fluid contacts to aquifer heterogeneity in a hydrodynamic environment, improving the understanding of tilted OWCs in fields, helping to explain dry wells and to improve planning and risk analysis for both exploration and development.
Journal ArticleDOI
Chalk exploration, the search for a subtle trap
TL;DR: The Chalk Exploration Project (CEP) as discussed by the authors was created to define the risked value of the remaining chalk exploration potential in licence PL018, where all major structures and significant amplitude anomalies at chalk level had been drilled by 1986, leaving only the subtle field flank and stratigraphic plays for evaluation.
References
More filters
Journal ArticleDOI
Capillary Pressures in Stratigraphic Traps
TL;DR: In this article, the authors used the Hobson equation to estimate pore sizes from mean effective grain sizes of the reservoir and barrier rocks, and then estimated pore and throat sizes as functions of mean effective grains size as based on theoretical packings of grains.
Journal ArticleDOI
Chalk Diagenesis and Its Relation to Petroleum Exploration: Oil from Chalks, a Modern Miracle?
TL;DR: In this paper, the porosity and permeability of nannofossil chalk ooze were studied and the major mechanism of chalk cementation is pressure solution and local reprecipitation.
Journal ArticleDOI
The petrology of the Chalk
TL;DR: Cretaceous chalk is a micritic limestone, mostly debris from planktonic algae, largely in micron-sized plates, but some still in their original circular groupings called coccoliths as mentioned in this paper.
Journal ArticleDOI
Overpressures in the Central North Sea: implications for trap integrity and drilling safety
TL;DR: In this article, a more detailed analysis combining the areal distribution of overpressures with the structural framework suggests that the Central North Sea Graben can be subdivided into several pressure cells.
Journal ArticleDOI
Porosity and hydrocarbon distribution in the North Sea chalk reservoirs
TL;DR: In this article, a 12-year experience of the North Sea chalks and the data from > 180 wells was used to establish and test on the other fields in the area and is described in this paper.