VERFAHREN UND VORRICHTUNG ZUR UMSETZUNG VON ROHRWELLEN IN KOERPERWELLEN, ZUR SEISMISCHEN EXPLORATION

摘要

For converting tube waves into body waves downhole for seismic exploration, a rotary valve tube wave source (8) is used for producing swept frequency tube waves that are injected into a liquid-filled tubing (1) or wellbore (2). The tube waves are converted to body waves by an elongate tube wave converter (5) located at a selected position downhole. The tube wave converter comprises an elongate metal body that preferably substantially fills the wellbore or tubing and has a preferred shape in order to convert efficiently the tube waves to body waves at the selected position downhole. The converter has a strong acoustic impedance contrast with the liquid in the wellbore or tubing. <IMAGE>