About This Item
- Full text of this item is not available.
- Abstract PDFAbstract PDF(no subscription required)
Share This Item
The AAPG/Datapages Combined Publications Database
Houston Geological Society Bulletin
Abstract
Abstract: Multidisciplinary Reservoir Description to
Characterize Connectivity in a Complex Minibasin
Fill: An Integrated Approach at Holstein Field
BP America Inc.
Holstein is a BP-operated, deepwater oil field located in the Gulf of Mexico. Reservoirs comprise stacked, Pliocene turbidite sands with the field formed by a large, steep, southeasterly dipping, monoclinal structure. Early performance of the field showed a sharper production decline than predicted by the sanction study. Dynamic simulation of early wells suggested limited drainage acreage confined by baffle regions with limited connection to the larger reservoir. A campaign of surveillance data was carried out. Subsequent drilling indicated the reservoirs, originally modeled as being in pressure isolation, were experiencing pressure-depletion through connections between reservoirs. A major effort was undertaken to recharacterize the reservoir, rebuild the static model and generate new dynamic simulations to update the development strategy and develop a mitigation plan.
The sanction case geological model described the reservoir sands as deposited in a ponded, intraslope salt basin dominated by thick, amalgamated reservoirs with internal homogeneity and excellent connectivity. The subsequent recharacterization describes reservoir architecture elements composed of sandy sheets and channels that shingle to form genetically related reservoirs. Baffling between geobodies and pressure-isolated compartments between some shingles are also recognized. Postdepositional modification of the reservoir further complicates well performance by removing the reservoir entirely or reducing its thickness. A structural overprint creates deformation bands that appear to reduce well productivity through the reduction of effective permeability in the structurally steepest segment of the field. In addition, seismically resolvable faults, originally thought to be sealing, are modeled as having variable transmissibility and allowing cross-flow between the complex reservoirs.
End_Page 13---------------
A revised heterogeneity
model calibrated with
dynamic data allowed
greater understanding of
the well performance variations.
The assisted
history-match approach of
Top-Down Reservoir
Modeling
(TDRM) was
utilized to handle the main
uncertainties in the field
and reach multiple models
with a good match to all
production and pressure
data available. These models allowed the analysis of production
strategies for optimizing recovery. The data that guided this model
rebuild, the integrated
modeling
process used, and the resulting
impacts on the depletion plan are described in this work.
Figure 5.
Seismic
facies are used to generate an architectural elements (or reservoir
depositional environment) map which shows the internal facies heterogeneity of
individual fans. In addition to the depositional elements, we capture the
post-depositional erosional zero edges.
End_of_Record - Last_Page 15---------------