Logging while drilling (LWD) tools acquire data with a time index and record data over most of the time the bottom hole assembly (BHA) is in the borehole (all when batteries are present). Depth-indexed data is extracted from the larger time-indexed acquisition data set. The time-indexed data is rarely requested or presented for evaluation. However, these time-indexed measurements contain great potential for understanding the reservoir. The opportunity exists to use stationary LWD data as a direct dynamic measurement of the formation and movement of fluids. These dynamic measurements can provide information on the quality of the mudcake at the time of measurement. There are also conditions where flow rates and, by inference, formation permeability can be derived from these time-based measurements (i.e., effectively injection logs while drilling). The examples shown illustrate some of the untapped potential that exists with every LWD data acquisition run, beyond the normal processing with depth-indexed data. Significant opportunities exist with this time-based data, from enhanced-quality measurements to the interpretation of dynamic downhole data.
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