3-D Forward Modeling and Simulation of Sediment Flow Distribution and Deposition, Ormen Lange Gas Field

The present study is aimed to evaluate, with the aid of the software MassFLOW3DTM, the sediment flow behavior and distribution of sand in the Ormen Lange Gas field. This is located 120 Km north west of the Møre coast, Norway, at a depth between 800 and 1100 m below sea level. The reservoir is 40 km long and 8 km wide, and the gas-bearing layers of sand are about 50 m thick.

The CFD software MassFLOW-3D™, has been developed and successfully used to construct a process-based, 3D model for the simulation of turbidity currents. All principal hydraulic properties of the flow and its responses to topography can be continuously monitored in 3D.Computational fluid dynamics (CFD) is a tool for numerical solution of the physical equations describing fluid flow and sediment transport. The method has been widely applied in the engineering branches of fluid mechanics, but has been little used in sedimentological research. Nowadays MassFLOW-3D™, is being developed to fill the gap between small and large scale, integrating data from theory, nature, and experiments. It can also shed light on flow parameters which are so far impossible to deduce from experimental and field studies.

The present project evaluated the possibility for the sediments, coming from a single source point located in the south-eastern side of the basin, to fill up the two existing depocenters, understanding how even subtle changes in the topographic relief could affect the sediments flow. Multiple grain sizes, as observed in the cores, are taken into account, showing how the presence of fine sand modifies the flow deposition. Different realization, having realistic conditions (position of the flow inlet, flow size and velocity, grain distribution) were analyzed, observing different possible scenarios.

One significant achievement is the verification that the flow coming from one single source point was capable to fill up both depocenters, reproducing realistically what mapped in the well-cores available. More information from the cores will give more indication about the nature of the flows (i.e. if they are erosional or depositional, grain size, flow direction, single surge or to multiple ones). In fact, several different scenarios may lead to similar depositional basins. Nevertheless only the finer structure observed in the cores can give indications to narrow the possibilities from several plausible flows to one specific one capable of creating the different layers observed.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California