K. B. Nolen, S. G. Gibbs, M. W. Connally and W. C. Lynch, Nabla Corporation
A new pressure transient wave method is presented for measuring fluid levels in wells, The method uses flow induced pressure phenomena to measure acoustic velocity externally from the well in a known length of coiled tubing. Similarly with a flow induced pulse in the well a fluid level is measured by sensing the distance traveled by the pressure wave. The method is flexible. The pressure wave can be created automatically or manually by venting a small amount of gas from the well, by abruptly releasing high pressure gas into the well or by implosion if the casing pressure is high. Simplified and less expensive equipment is involved. The method is applicable to routine surveillance, well productivity studies, lift equipment design and reservoir evaluation. Fluid levels measured with the new method compare favorably with those obtained with traditional techniques.