High-Resolution Multi Cross-Section Restoration and its Applications in Reservoir Quality Prediction

Abstract

Cross-sections restoration is a well-known technique widely employed by petroleum geoscientists to validate structural interpretation of seismic data by reversing deformation and sequentially removing restored layers. The results can be used to understand structural evolution, to set the timing of tectonic events and thermal history, to quantify strain distribution, and to evaluate migration pathways. In this work, we show how multi cross-section restorations can be helpful to study the relationship between deformation, sedimentological and stratigraphic processes during development of rift systems. The computational evolution of restoration software during last decade has been improving the techniques of cross-section restorations. Today, it is possible to restore seismic data and put reflectors to original positions in complex tectonic settings. It is also possible to rebuild facies architectural elements to original position and associate structural features and depositional geometries. The methodology presented here aims to restore depositional surfaces using multi cross-section restorations. The emphasis in these processes is to respect both structural and stratigraphic interpretation. Beside structural interpretation like faults and folds, it is necessary to define all reflector terminations (e.g. onlaps, downlaps, toplaps, and truncations) that limit different seismic patterns and stratigraphic sequences. During restoration, it is important to consider top layer geometries of depositional elements to preserve their original forms like mounds, buildups, channels, progradations, and platforms. The multi cross-sections mesh should be regular with dip sections oriented parallel to the strain plane, and with perpendicular strike sections. After multi cross-section restoration, results are gridded in paleogeomorphologic maps, where it is possible to analyze the relief during sediment deposition and its associations with tectonic structures. Time-space graphs can be produced to evaluate the relationship between subsidence and sedimentation rates, which are important to predict the reservoir distribution. As application examples, we are going to show restored sections and maps, and graphs of lacustrine carbonate and siliciclastic successions of the Lower Cretaceous along the continental margin of Brazil.

AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018