ELECTROMAGNETIC ACOUSTIC MEASUREMENTS IN A BOREHOLE COMBINEDWITH ACOUSTIC WAVE ANALYSIS

摘要

A method and apparatus for assessing the permeability of a subterranean f ormation (6) and the hydrocarbon and/or water content of the formation. The method includes emitting (12) an acoustic signal, such as a Stoneley wave in to the formation and sending (20) an electro-magnetic pulse into the formati on. An analysis of the response of the Stoneley wave in conjunction with an analysis of a measurement of the electrical potential within the wellbore (2 ) provides information pertinent to permeability and fluid composition.