Crews, Steven G.1
(1) Anadarko Petroleum, The Woodlands, TX
ABSTRACT: Map-Based Charge Modeling in the Eastern Black Sea, Offshore Georgia
A practical approach to modeling exploration charge risk that is both rapid and
comprehensive is proposed and illustrated using a case study from the Georgian sector of
the Black Sea. Regional and prospect-scale analyses were conducted; large uncertainties in
the values of key parameters such as source-rock depth and heat flow in this undrilled
frontier province were addressed using Monte Carlo techniques.
Our approach centers around pseudo-3D models based on high-resolution (typically
105 grid
cells) maps of chronostratigraphic surfaces. Burial history and paleostructure are
obtained through backstripping. Convolution of the burial history with empirical or
theoretical models for vertical and lateral temperature prediction, and with source rock
properties, allows simulation of thermal maturity history and predictions of generated and
expelled volumes through time. On any map surface, fetch areas can quickly be determined
for prospective structures using non-Darcy migration techniques, and the total expelled
volumes within each fetch area are calculated by summing the contributions of each grid
cell. This process is fast enough to run hundreds or thousands of Monte Carlo
realizations, in which the sensitivity to variation in 9 key input parameters is analyzed.
Liquid and vapor column heights and leaked or expelled volumes can be predicted for each
trap based on estimated reservoir, fluid and seal properties and P-T conditions.
The workflow presented here is enabled by two recent technological developments: (1)
increased availability of semi-regional digital map grids based on seismic data; and, (2)
dramatic improvements in the performance of personal computer hardware and software. The
ability to import and manipulate large data sets, do rapid interactive maturity and flow
path modeling, and visualize the model in 3D makes this approach practical, efficient and
useful.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.