First Break - Volume 29, Issue 6, 2011

Christa Hammerl, Wolfgang Lenhardt, Roman Leonhardt and Harald Granser describe the remarkable career of Victor Conrad and the naming of Austria’s latest geophysical observatory as a tribute to his achievements principally in the fields of climatology and seismology.

From experience as a practitioner and educator Rob Simm provides a personal view on rock physics applications in seismic interpretation.

H. Morris, B. Hardy, E. Efthymiou and T. Kearney highlight the steps used to take us from a petrophysics to reservoir model introducing methods to improve the data quality via seismic data conditioning and highlighting some of the benefits of using a sequential Gaussian inversion over more conventional deconvolution style inversion methods.

Donald Keir, Brett McIntyre, Ted Hibbert, Rachael Dixon, Klaas Koster, Farid Mohamed, Adam Donald, Anzar Syed, Chang Liu, Tom O’Rourke, Andrea Paxton, Steve Horne, Ed Knight, Colin Sayers and Paolo Primiero describe how a method employed to quantify anisotropy and correct sonic logs across the Forties field led to modifications of drilling parameters and practices and ultimately to significantly improved efficiency/productivity.

Michelle Ellis, Franklin Ruiz, Sriram Nanduri, Robert Keirstead, Ilgar Azizov, Michael Frenkel1 and Lucy MacGregor discuss how compositional and structural features of the subsurface rock strata at different length scales affect the elastic and electrical properties and induce anisotropy. Rock physics models are presented which calculate elastic and electrical anisotropy from the volumetric fractions of solids and fluids in the rock, and the microstructural information within the rock.

Joel D. Walls and Steven W. Sinclair report on a workflow for analysis of cores samples from two wells in a shale reservoir focused primarily on the relationship between porosity and permeability in the stratigraphic zone of interest.

Angeleena Thomas, Malcolm Rider, Andrew Curtis and Alasdair MacArthur propose a novel approach to lithology classification from core photographs based on object-based image analysis, an advanced method used in remote sensing and medical imaging.

From Prof Dr Jan de Jager, Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands.

The evolution of the North German Basin is of particular interest due to the fact that it is an important hydrocarbon province with considerable reserves of natural gas. There have been several previous studies on the stratigraphy, structural evolution, and geochemical characterization of the basin, but no large-scale petroleum systems model has previously been published. We have developed a fully integrated numerical petroleum systems model, with emphasis on Palaeozoic pretroleum systems, taking into account the thermal subsidence history to calculate maturity levels, temperatures, and other related parameters. As one result of the study, we have produced maps of temperature and maturity for different time steps. We have also calculated the dynamics of gas generation and accumulation for different parts of the basin. This large-scale petroleum system model for the North German Basin can be applied in future exploration because it gives important clues concerning migration, accumulation, and escape of gas in the course of basin evolution.

When Saga Petroleum drilled a deep exploration well in the southern part of the North Sea in 1989, it encountered a high pressure zone, and the well developed into an underground blowout that lasted for 326 days. A relief well was spudded 11 days after the blowout, and the underground blowout was successfully killed by pumping drilling mud of high density, 2.25 g/cc, into the blowing well. During this period, Saga Petroleum decided to use shallow seismic data to monitor the underground blowout. Ten monitor surveys were acquired during and after the blowout, and this campaign is probably the first successful time-lapse seismic acquisition done in the Norwegian part of the North Sea. In 2009 some of these 2D lines were repeated, using approximately the same acquisition parameters as in 1989 and 1990. Comparing the seismic data from 2009 with the data from 1990 and 1989, most of the gas appears still to be in the same layers as in 1990. There has been some lateral migration of gas, and only a minor amount of vertical gas migration.

Seismic reflection data foster geological intuition when they resemble geology. With a simple workflow based on modern seismic attributes and tools for interpretive processing and display, it is straightforward to display seismic data to look more like geology. This workflow combines structural and stratigraphic attributes through volume blending with illumination. Illumination imparts a 3D texture to the display, enhancing structural elements in the data. Two important structural attributes are relative amplitude change and seismic shaded relief; they look illuminated naturally. Shaded relief is especially useful as it makes time slices look like apparent topography and vertical sections look like canyon walls, thereby revealing faults, anticlines, diapirs, channels, and other features.