Integration of Dynamic & Geostatic Data Improves Reservoir Characterization

Abstract

Abstract Integration of the dynamic data and geologic data led to a significant enhancement in understanding the reservoir flow behavior of a major limestone reservoir in the Arabian Gulf. High-permeability streaks were found to be the main factor controlling the reservoir performance and water breakthrough in the northern sector of the field. The methodology presented in this paper integrates static and dynamic data in such a way to ensure consistency between the data and enable better understanding of the reservoir flow characteristics. The study accommodates all available data from core, well test, O.H. logs, PLT, PNC logs and production data. Core data was used to identify the permeability variations vertically and horizontally. In order to extend the knowledge and map the area where the high-perm streaks exist, well test, production logs, TDT/PDK logs, production and injection data were used to link the reservoir heterogeneity on well-well and on a field scale basis. Statistical wire line log analysis was conducted and found that the Rxo log response was quite useful for reservoir characterization in this regard. The results of the analysis showed good consistency with what was concluded from dynamic data. The core and dynamic data indicate the high-permeability streaks cannot be correlated all over the reservoir, they are strictly present in the northern sector. There is a clear borderline splitting the reservoir into two sectors, the high permeability northern sector, and the low permeability southern sector. The profiles measured with the production logs (WFL & TDT/PDK) consistently indicated the presence preferential behavior that interpreted as a high–permeability streaks at the top part of the reservoir. A linear increasing WOR trend of the wet producers is a clear indication of presence of permeability contrast that interpreted as a presence of hi-permeability streaks. The dual-permeability/porosity behavior as interpreted analytically utilizing pressure transient data found to be the response of the presence of hi-permeability streaks. This paper shows how data integration improved our understanding of reservoir performance and reduced the production uncertainty of this heterogeneous limestone reservoir. The modified 3D simulation model matched, for the first time, the reservoir water cut performance.