Enhanced use of well site gas data and the influence of technology while drilling

Abstract

This short program demonstrates how real-time chromatographic analysis of light hydrocarbons can provide effective fluid characterization with the identification of fluid changes, zones and contact points, as the reservoir is being penetrated. The clear advantage of this is that reservoir fluids are analyzed immediately, before contamination by mud invasion can alter the characteristics of formation fluids adjacent to the borehole, which can often be detrimental to subsequent electrical analysis. In addition to such reservoir analysis, high speed chromatographic analysis also provides the necessary resolution for the techniques to be applied to the steering of horizontal wells. While Logging While Drilling (LWD) is an effective technique, it is also an expensive one and costs can be dramatically reduced by the application of gas analysis to geosteering. A further benefit is often realized through more rapid course corrections (depending on the relationship between lag time and penetration rate versus tool placement, and when changes are recognized at surface) minimizing the amount of missed pay.