Characterization and Quantification of Structural and Stratigraphic Heterogeneities in Deep Water Settings

Onyeagoro, Kachi U.¹, Frans F. Van Der Vlugt¹, Steve J. Naruk¹, Mark Barton² (1) Shell International Exploration and Production Coy. Inc, Houston, TX (2) Shell International Exploration and Production, Houston, TX

Recent successful exploration and production programs in deepwater settings worldwide have increased the need to better understand the range of structural and stratigraphic depositional complexities. As oil and gas companies explore and produce hydrocarbons in deeper water settings, and in their quest to produce difficult and unconventional hydrocarbons and tight gas, there is need to innovate smart and genius ways of achieving success and reducing the overall cost.

The first technical principle of achieving this success is better understanding, characterizing and quantifying structural and stratigraphic heterogeneities. The first generation deep-water fields in the Gulf of Mexico are structurally and stratigraphically simple, penetrated by multiple wells and producing at high rates with gradual pressure declines. The second-generation deep-water fields in are structurally and stratigraphically complex and are posing more challenges in development. Lack of understanding of these heterogeneities and their challenges have led to the beleaguered problem of compartmentalization in the second-generation deep-water reservoirs.

Many structural and stratigraphic features that do not define pressure compartments prior to production become significant barriers to flow during production, necessitating the drilling of more wells. The key problem is to predict where such barriers will occur, and breakdown, during production.

The importance of realistically characterizing and quantifying these heterogeneities has been demonstrated in many Deep Water Nigeria, Deep Water Brazil, North Sea and Gulf of Mexico fields. These characterizations have yielded accurate and better-defined drilling well paths across faults and different stratigraphies, robust field development plans with clear economic advantages, and successful history matches.