An Integrated Approach for the Study of Deep-Water Reservoirs

Empinotti, Thaís C.¹; Paraízo, Paulo ¹; Moraes, Marco ¹; Oliveira, Tiago ¹
(1)PETROBRAS Research Center (CENPES), PETROBRAS, Rio de Janeiro, Brazil.

Petroleum exploration and production in deep-water systems have been continuing developed for several decades and during this time these reservoirs have been the main hydrocarbon play of Brazil in terms of oil production. This experience generated a great amount of knowledge and a vast and varied database related to these reservoirs, including subsurface and outcrop data, modern systems surveys and, more recently, physical and numerical modeling. The challenge is to integrate these different kinds of information and scales of observation, aiming to elaborate more universal depositional models for the deep-water reservoirs and to achieve a more genetic characterization of the different types of depositional patterns. The main objective of the models developed herein is to provide an easy-to-use tool for reservoir characterization studies.

The initial task was to perform a review of the depositional models proposed in the literature and an exhaustive comparative analysis of several outcrop studies elaborated through JIP’s and Petrobras own studies. Thereafter a classification proposal of the main deep-water depositional patterns at the scale of depositional complex was developed (km-scale, close to the scale of the patterns observed on seismic data), and a database of the main patterns in terms of seismic expression, log motif, outcrop analogs and lithofacies was linked to the classification. A parametric database is attached to every pattern to be used for reservoir modeling.

The depositional models were created in the form of energy matrices, where the depositional patterns are located relating to the stratigraphic phase and the position along the slope-to-basin profile. As a function of the position of a given pattern it is possible to predict some important characteristics such as mud content, size of depositional elements, main lithofacies, sand amalgamation rate, and sand-body stacking trends. These informations are used for reservoir management. Once the main pattern corresponding to a reservoir is identified, the qualitative and quantitative data are used, for example, for generating the reservoir 3D model that supports the production projects. Examples of applications in Campos basin deep-water fields are presented.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.