Sansonowski, Rui C. (PETROBRAS/UN-BC/ATP-MRL/RES) | de Oliveira, Rildo M. (PETROBRAS/UN-BC/ATP-MRL/RES) | Júnior, Nier Maciel da S. (PETROBRAS/UN-BC/ATP-MRL/RES) | Bampi, Dirceu (PETROBRAS/UN-BC/ATP-MRL/RES) | amarão Junior, Luciano F. (PETROBRAS/UN-BC/ATP-MRL/RES)
The growing application and acceptance of 4D or time-lapse seismic technique as a key reservoir management tool has been well documented. The technique has been successfully applied to numerous mature fields in order to optimize reservoir production and recovery. This paper will describe such a case study on the Marlim Field where the application of 4D seismic has contributed significantly to critical reservoir management decisions. The giant Marlim field is located on the eastern Brazilian coast in water depths varying from 600 to 1200m. The reservoir is characterized by an unconsolidated sandstone turbidite related to the regressive mega sequence of the Brazilian eastern continental margin. It is the largest producing oilfield in Brazil (average 450.000 bpd), with the original oil-in-place volume of 6.4 billion STB. Production started in 1991 and injection of water in 1994. Three seismic surveys cover the Marlim Field. The first one was acquired in 1986, the others in 1997 and 2005. The most recent survey was acquired using WesternGeco's Q-Marine acquisition system and was specifically acquired for reservoir monitoring and characterization purposes. Analyses of the 4D results started in June 2006 after parallel processing of the 1997 and 2005 datasets. This paper will highlight how the results of the 4D interpretation are being used to make critical reservoir management decisions with greater confidence and reduced risk.
This paper presents the application of source signature deconvolution for improving the resolution of VSP data and removing shot-to-shot variations. The method has low complexity and requires minimal changes to current deployment and acquisition practices, and is applicable for land and marine surveys. We have applied the algorithm to vertical incidence offshore data. The method successfully removes shot-to-shot variations, and compresses the wavelet to zero phase, improving the resolution of the data and uncovering events which were hidden by the long air gun signature. We suggest this method should be adopted as a routine processing step in all VSP surveys, although the technology will be of greatest benefit in time-lapse experiments.
Parra, Jorge (Southwest Research Institute, San Antonio, Texas) | Hackert, Chris (Southwest Research Institute, San Antonio, Texas) | Richardson, Emily (South Florida Water Management District, Florida) | Clayton, Ned (Schlumberger Water Services, California)
Standard geophysical methods for monitoring CO