The introduction of downhole fluid analysis (DFA) two decades ago was a major addition to the wireline formation testing suite of measurements previously available in the industry, both in to optimize the sampling operations real-time and to provide additional fluid measurements as an integral component of integrated fluid property interpretations. The progression from basic measurements such as fluid resistivity to advanced optical analysis has paved the way for much improved definition of reservoir fluids, including the variation of fluids within reservoirs.
Downhole Fluid Analysis is a continuously evolving field, so we will begin this paper by looking back at the history and evolution of various types of sensors for operational real-time decision making as well as post-operational fluid evaluation. Our emphasis will be to catalogue the strengths and limitations of each method and highlight the importance of integration. We will then highlight current capability gaps, focusing on the need for improved real-time contamination monitoring in some environments of interest and our desire to measure additional fluid properties and specific species concentrations.