Estimating the value of seismic in the life cycle of Brazil pre-salt Fields
Brazil pre-salt is famous for head-line reserve numbers and well productivities. On the other hand, there is also heavy upfront capital investment needed in billions of dollars by the companies. These billion-dollar decisions are made very early in the life-cycle of the field on limited information, with the consequence may only be realized years or decades later. Underlying these, the pre-salt subsurface is represented by complexities like heterogeneous carbonate facies, “Brazil-unique” layering salt, presence of igneous rocks and diverse fluid type. They pose significant uncertainties and risks to the geoscientist and engineers to provide a realistic range of subsurface models to assist optimal decision making. The appraisal phase is when the risks and uncertainties are timely reduced by proactive and active data gathering like wells, seismic or testing. The challenge is to gather the right data at the right time to assist the right decision making. With more focus are on shorter cycle time from discovery to first oil, the demand for fast appraisal is only getting bigger. Seismic is one of the key datasets that can reduce the uncertainty and risks early and significantly, and its use spans the whole life-cycle of the fields. The reality though for the pre-salt is that majority of available seismic data are narrow azimuth and short offset (less than 8km). They are often not suitable for development and production purposes, in which more or full azimuths and/or longer offsets are needed. In this talk, we will discuss the options available post discovery. VOI on capital investment decisions are used to illustrate the need to decide early, and acquire a development-suitable seismic in the appraisal phase. Even after the decision to acquire early, we still face the challenge of the long-cycle acquiring and processing time, that may undermine the full value of the new seismic. To overcome this, we need support from regulators, collaboration among companies, technology innovations and workflow optimization.
AAPG Datapages/Search and Discovery Article #90352 © 2019 AAPG Latin America and Caribbean Region Geoscience Technology Workshop, Rio de Janeiro, Brazil, June 13-14, 2019