Laggan Field 3D geological modelling: case study
L. H. Kheidri, F. Cailly, K. Jones, A. De Senneville, R. Gray, 2014. "Laggan Field 3D geological modelling: case study", Hydrocarbon Exploration to Exploitation West of Shetlands, S. J. C. Cannon, D. Ellis
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Drilling of Laggan development wells commenced in summer 2013 and finalization of well locations required updated reservoir models, fully incorporating the 2009 baseline seismic. Consequently, geomodelling workflows have been developed based on the 3D seismic, petrophysical and production test data. The reservoir model building methodology for Laggan consists of the following steps: (1) construction of a classical structural framework using seismic interpreted fault sticks, top reservoir depth surface and the overall reservoir thickness map estimated from seismic data; (2) building of zones model integrating well data, seismic and sedimentological concepts; and (3) generation of a 3D facies and petrophysical model constrained by seismic and well data, including well test results to calibrate the permeability.
A reasonable match of the well test data was achieved without any major adjustments to the reservoir model. This methodology has led to the construction of a robust reservoir description, capturing the geological knowledge of the turbidite system and constrained by well and seismic data.
The new Laggan model is now considered ‘fit for purpose’ for well locations update, well type and well number confirmation and development of the Reservoir Management Plan.
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This volume addresses the challenges facing explorers and developers alike in a region that is becoming a major focus of the petroleum industry in the United Kingdom, Faroes and North Norway. Several West of Shetland fields are still in the appraisal phase almost a decade after discovery. Sub-volcanic exploration risks remain high: sub-volcanic structural traps are imaged poorly, and so the geophysical community is responding with the application of latest technology. The more simple reservoirs might not be large enough to prompt informed and speedy development decisions; larger fields might have a combination of complexities, requiring a phased approach to the development. Infrastructure has been slow to arrive and planned developments have been subject to dramatic swings in fiscal regime ranging from special allowances to unexpected tax increases.
Environmental challenges are significant when moving into more remote, deeper water. The perception of these challenges by the third parties has become much more acute. To sustain its right to operate, the industry has to demonstrate safe drilling operations and appropriate response capability with government agencies.