Barton, Mark1, Ciaran O'Byrne2, Carlos Pirmez2, Brad
Prather2, Pieter Slik2, Ru Smith3, Gary S. Steffens2,
Frans Van der Vlugt2
(1) Shell International Exploration and Production, Houston, TX
(2) Shell International Exploration and Production,
(3) Shell International Exploration and Production, Netherlands
ABSTRACT: Understanding Hydrocarbon Recovery in Deepwater Reservoirs: Modeling Outcrop Data in the Third Dimension
Deepwater outcrops provide valuable information on the presence and probability of
occurrence of baffles and barriers to hydrocarbon flow within analogous reservoirs.
Understanding the impact that these features have on fluid flow requires that
two-dimensional outcrop data sets be extended into three-dimensional reservoir models.
This is particularly important for complex deepwater channel reservoirs, whose large
capital development expenditures drives the need for wells capable of delivering high
ultimates at high rates. Several methodologies are used to construct realistic 3D models
of turbidite channel architectures from 2D outcrop data with a few simple geologic rules.
Channel to inter-channel architecture is modeled in 3D by combining outcrop data on
channel-form width and thickness, the proportion of channel to interchannel facies,
channel-form density, and channel stacking patterns through time (compensating, laterally
migrating, vertical stacking) with information on channel planform geometry (sinuosity,
wavelength, amplitude). Intra-channel architecture is modeled in 3D by combining outcrop
data on bed thickness, frequency and distribution of channel base drapes, frequency and
distribution of intra-channel shales, and the cross-sectional infill geometry (layered,
convergent, accretionary) with information on sand and shale bed lengths parallel to the
channel axis. Petrophysical properties are assigned by facies from similar subsurface data
sets.
Models honoring all these outcrop measurement statistics provide the ability to test
scenarios that address specific variables that cannot be measured directly. Results of
dynamic simulations in several deepwater outcrops illustrate the impact that various
geologic features have on fluid flow and recovery efficiency.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.