Field test of monitoring gas reservoir development using time-lapse continuous electromagnetic profile method

We have carried out a field trial of a time-lapse continuous electromagnetic profile (CEMP) method for monitoring gas reservoir development. Several data acquisition methods were tested to establish a field-worthy practical procedure that maintained the consistency of time-lapse CEMP acquisition and ensured the reliability of collected data. An effective denoising and static correction algorithm has also been developed to sufficiently suppress noise and disturbance for data processing purposes. The resistivity variation with time was recovered using a time-lapse inversion method. Three continuous acquisition tests on a gas reservoir in western China produced results that clearly indicated the relationship between resistivity change and the change in gas and water ratio as well as pressure decreases. The field trial was a successful experiment in monitoring gas reservoir development with high-precision time-lapse CEMP surveys. The established data acquisition procedure, data processing algorithm, and the inversion-based interpretation have general applicability, and these may open new avenues for time-lapse monitoring in oil and gas production.