Jonny Hesthammer, UiB, Bergen, Norway
Francisco Porturas, ScanViz,
Subsurface Integration The Fifth Dimension: A Case Study From the Gullfaks Field, Northern North Sea
In order to fully understand the structural reservoir characteristics, it is necessary to integrate results from detailed analysis of core data, dipmeter data, image data, well log correlation data, seismic data and field analogue data. Such an integrated approach will allow for a fuller understanding of the variations in fluid flow patterns within the reservoir, optimal placing of wells and optimized well completions.
We present an example of integrated analysis carried out on the Gullfaks Field, Northern North Sea. In this case study, dipmeter data (here exemplified by the use of resistivity imaging data) from well 34/10-B-12 and seismic data helped in finding the orientation of a fault associated with 69 m of missing section (as observed from well log correlation data).
Core data from the well allowed for examination of deformation structures as well as permeability and porosity measurements.
From thin section analysis it is possible to observe how phyllosilicates effectively seal the micro-fractures (deformation bands), thus restricting fluid flow across the fractures. Core data demonstrates that all faults in the sandstone reservoir on the Gullfaks Field are associated with numerous deformation bands in a narrow damage zone near the fault. Since each of the deformation bands restrict fluid flow, an understanding of the spatial distribution (from well data, seismic data and field analogue data) and petrophysics (permeability and porosity) associated with faults on the Gullfaks Field is crucial in order to optimize field development and in cases where ‘downhole factories’ or well completions using Inflow Control Devices could be the future scenario.
Today, visualization technology allows one to add value to the data, where asset teams make decisions in collaborative environments and reservoir management optimization facilitated by “real time” data access.