Benefit of Data Integration (Biostratigraphic Data) in Field Development –B4 Gas Reservoir Case Study

Abstract

The management of uncertainties associated with ‘green fields' remains a challenge due to data paucity. In the context of rising development costs for oil and gas projects, integration of data from all available sources becomes imperative. This integration has been demonstrated to reduce identified subsurface uncertainties and risks. Biostratigraphic data which comprises use of forams and fauna from ditch cuttings picked in several reservoirs in the field has been evaluated and is used to delineate the sequence stratigraphic boundaries which have been shown to be useful for building the framework for field correlation, thus the building of realistic static models. The CAMOY Gas field located onshore Niger Delta basin was discovered in 1961 by CAMO-1 well. To date, a total of six wells have been drilled in the field. The field is split into two fault blocks by CAMO fault (an East-west trending fault) in the south. The minor block is penetrated by just one well, with the remaining five wells in the main block. A total of nine hydrocarbon-bearing reservoirs have been penetrated occurring between the depths of 6500 ftss and 11000 ftss. Key subsurface uncertainties that impact on the development plan of the B4 gas reservoir have been identified, and they are associated with structure and stratigraphy. A range of static volumes were computed initially based on the original understanding of the underlying structural and stratigraphic uncertainties. However, by integrating biostratigraphic data in the reservoir correlation, the uncertainty associated with stratigraphy is reduced, leading to a more realistic range of volumes. Following the building of a realistic 3D model and volume ranges, two wells have been proposed to be drilled to develop the reservoir. The placement of one of the wells closer to the CAMO fault has been optimized post application of biostratigraphic data in B4 gas reservoir correlation.