--> Abstract: 3-D Seismic Stratigraphic Inversion: a Lithology-Based Approach for Seismic Reservoir Characterization in Deep Water Campos Basin, by C. E. B. S. Abreu, P. R. S. Johann, L. C. S. Freitas, C. H. L. Bruhn, R. Beer, D. J. Sarzenski, and Z. Camoleze; #90933 (1998).
[First Hit]

Datapages, Inc.Print this page

Abstract: 3-D Previous HitSeismicNext Hit Stratigraphic Inversion: a Lithology-Based Approach for Previous HitSeismicNext Hit Reservoir Characterization in Deep Water Campos Basin

Abreu, C. E B. S.; P. R. S. Johann; L. C. S. Freitas; C. H. L. Bruhn; R. Beer; D.J Sarzenski; Z. Camoleze - Petrobras/E&P

Most barriers to vertical fluid flow are easily recognized in well logs, such as gamma-ray and neutron-porosity logs. Reservoir heterogeneities (e.g. interbedded mudstones and calcite-cemented horizons) in turbidites from deep water Campos Basin usually show subtle responses in conventional Previous HitseismicNext Hit amplitude data (Fig. Previous Hit1Next Hit); this may be due to their reduced thickness and/or the low acoustic impedance contrast between the non-reservoir layers and the reservoir sandstone. Nevertheless, the mapping of these heterogeneities is very important for defining the reservoir drainage strategy, particularly the positioning and completion of horizontal and deviated wells. Nowadays, a great effort is being undertaken to overcome these obstacles.

The use of 3-D Previous HitseismicNext Hit stratigraphic post-stack inversion is proposed to improve reservoir characterization, by using both inverted acoustic impedance and reflectivity images. This technique involves the use of three main types of data: (Previous Hit1Next Hit) a conceptual, regional stratigraphic model, (2) a well-log derived acoustic impedance model, and (3) a stacked and migrated 3-D Previous HitseismicNext Hit volume. The expected results include a better description of the reservoir internal and external geometry, the assessment of reservoir properties in non-drilled areas, and a Previous HitseismicNext Hit processing quality control tool, by investigating the final residual volume from the inversion procedure. A great advantage of this methodology is the integration of Previous HitseismicNext Hit information and well-log data at the oil-field scale.

The study area, a giant oil field from deep water Campos Basin, includes 26 wells with sonic and density logs, which provided a reliable spatial variant a priori information, the geostatistically-based acoustic impedance model generated from well-log data. The Previous HitseismicNext Hit-derived volumes, constrained by well information and conceptual stratigraphic models, enabled a more accurate mapping of the reservoir boundaries (Fig. 2) and the prediction of the reservoir properties (particularly in the inter-well area).

The 3-D Previous HitseismicNext Hit stratigraphic inversion procedure consists of five main steps: (Previous Hit1Next Hit) volumetrically constrained well-Previous HitseismicNext Hit calibration, (2) stratigraphic deconvolution, (3) 3-D acoustic impedance modeling, considering the well and stratigraphic information, (4) Previous HitseismicNext Hit stratigraphic inversion, (5) interpretation of the high- resolution, inverted Previous HitseismicNext Hit volumes. The uncertainties associated to well-log acoustic impedance and Previous HitseismicTop data values are also taken into account, controlling the freedom degree in which the final solution is obtained.

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil