3D-Modelling of Coastal Plain Deposits from the Blackhawk Formation, Eastern Utah

Carlsson, Christian Göran¹, Tor Sømme¹, Håvard Enge¹, Simon John Buckley¹, John Anthony Howell¹ (1) University of Bergen, Bergen, Norway

The Blackhawk Formation crops out in the Book Cliffs of eastern Utah and includes a thick succession of marginal to nonmarine coastal-plain deposits. These deposits form an excellent analogue for heterogeneous coastal-plain reservoirs such as the Ness Formation of the North Sea Brent Group. A general characteristic of such reservoirs is the relatively low recovery associated with the complex, discontinuous geometry of individual sandbodies. Significant quantities of oil can remain within low net-to-gross fluvial reservoirs and consequently outcrop studies can shed light on suitable modelling strategies.

Data were collected at two occasions from a 20 km² area of the Book Cliffs known as Woodside Canyon. Data were originally collected using a combination of traditional mapping techniques and calibrated photomontages. The locations of all logs were digitally mapped using GPS. Data were then digitised and taken into RMS, a reservoir modelling software.

At the second occasion data were collected with a terrestrial laser scanner. This allows for high resolution point-data sets and the option to texture the data with images taken with a digital camera calibrated to the scanner, resulting in a high resolution virtual outcrop. These data were then correlated with sedimentary logs and taken into RMS.

3D-models were built for each data set and a quantitative comparison was carried out, highlighting differences between the two techniques. Finally the models were compared by flow simulations to determine differences in sandbody connectivity.