In-Situ Characterization of Formation-Fluid Samples - Case Studies

Abstract

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 90932, "In-Situ Characterization of Formation-Fluid Samples - Case Studies," by H. Elshahawi, SPE, and M. Hashem, Shell Intl. E&P Inc., and C. Dong, SPE, P. Hegeman, SPE, O.C. Mullins, SPE, G. Fujisawa, SPE, and S. Betancourt, SPE, Schlumberger Oilfield Services, prepared for the 2004 SPE Annual Technical Conference and Exhibition, Houston, 26-29 September. Fluid sampling in the early stages of exploration and development provides key information for field planning and facilities design. In many deepwater and other high-cost wells, formation-tester samples may be the only reliable source of fluid properties for economic screening. Real-time in-situ fluid characterization can ensure sample quality and optimize the sampling process. Techniques for downhole fluid characterization include real-time composition measurement, fluid-type identification, and single-phase assurance. Introduction To develop deepwater prospects and other capital-intensive E&P projects, it is essential to understand the precise nature of the hydrocarbon fluids in terms of chemical and physical properties, phase behavior, and commingling tendencies. This understanding is essential to optimize completion and facilities design and reservoir-production strategies. Gas/liquid ratio, saturation pressure, and viscosity are fluid parameters that determine whether and how production is pursued. Phase transitions such as asphaltene onset, wax and organic-scale deposition, gas-hydrate formation, and diamondoid accumulation can reduce production substantially. Consequently, getting the correct answer at the beginning of a project is necessary.