The Application of Real Time Downhole Drilling Dynamic Signatures as a Possible Early Indicator of Lithology Changes

Abstract

Abstract While geosteering wells through hydrocarbon producing formations, early and decisive decision making during the real time (RT) drilling process is fundamentally key to whether the particular well is going to be a good producer, or an exceptional hydrocarbon producer. Typically, within today's modern Logging While Drilling (LWD) tool suites the bulk density and porosity tools are offset behind the drill bit by the motor, Rotary Steering Systems (RSS) and other bottom hole assembly(BHA) components. Offsets will by their nature incur some data time lag period, determined by the ensuing Rate of Penetration (ROP). By using RT downhole drilling dynamics the decision process tree can be enhanced and quickened. Changes in drilling system dynamics driven by the bit's interaction with the formation, will be a near instantaneous indicator of changes in formation characteristics and properties. The key being this dynamic data is coming directly from bit depth. These early RT drilling dynamic changes could be used in collaboration with the existing modern Reservoir Navigation Steering (RNS) techniques, to provide earlier decision making. In this paper the authors will present, discuss and aim to demonstrate and fully explore the relationship and potential usefulness between the RT drilling dynamic signatures and formation bulk density or porosity changes.