Print this pageAn Innovative Approach to Evaluate Probabilistic Reserves for Green Fields Utilizing Engineering and Geological Knowledge: Negage Field, Block 14 Deepwater Angola
Masroor M. Chaudhri1, Stefan Lattimer2, Kathleen Mabe2, Yan Chen1, Janet Yun1, Alda Agostinho3, and Mario Dias3
1ETC, Chevron Corporation, Houston, TX
2SASBU, Chevron Corporation, Houston, TX
3Sanongol P&P, Luanda, Angola
The Negage field was the first discovery south of the Congo Canyon in Angola Block 14 by the contractor group consisting of CABGOC (the operator, a Chevron company) Sonangol P&P, ENI, GALP, and Total. Discovered in October 2002, Negage field is located in 4,500 feet of water. The Congo River Canyon separates the Negage field from other Block 14 infrastructure, including the BBLT and Tombua-Landana developments. The Negage reservoirs consist of high-quality deepwater turbidite channel sands of Miocene age.
Negage field is composed of many satellite reservoirs which are spread over 200 sq. miles. Evaluation of whole Negage prospect with one geological model is almost impossible due to enormity of the development area. Conventional workflows consist of seismic interpretation, geological model construction and full field development plan using simulation model. Complete evaluation of a prospect can take months to years.
We propose a three step process to determine the full potential of a prospect. First step involve the calculation of map based volumes from seismic data. Material balance models are constructed based on map based OOIP and properties from analogues reservoirs. Design of experiments is performed for each of these reservoirs to determine the probabilistic reserves distribution. This exercise is carried out for all the reservoirs in the development area to determine the full potential of the prospect.
This methodology substantially reduced the cycle time to evaluate the prospect and helped the project team to identify and focus their efforts on reservoirs that are more important to make the project successful.
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