초록 ▼

This invention is directed toward apparatus and methods for obtaining acoustic measurements or "logs" of earth formations penetrated by a borehole. More particularly, the invention is directed toward obtaining the acoustic measurements while the borehole is being drilled. The downhole apparatus comp

This invention is directed toward apparatus and methods for obtaining acoustic measurements or "logs" of earth formations penetrated by a borehole. More particularly, the invention is directed toward obtaining the acoustic measurements while the borehole is being drilled. The downhole apparatus comprises a plurality of segmented transmitters and receivers which allows the transmitted acoustic energy to be directionally focused at an angle ranging from essentially 0 degrees to essentially 180 degrees with respect to the axis of the borehole. Downhole computational means and methods are used to process the full acoustic wave forms recorded by a plurality of receivers. A two way communication system is also used in the preferred embodiment of the invention.

대표청구항 ▼

[ What is claimed is:] [1.] A measurement-while-drilling (MWD) tool for use during drilling of a wellbore having a longitudinal axis in a formation having a reflecting interface, comprising:(a) a tool body;(b) a plurality of spaced apart transmitter arrays carried by the tool body, each said transmi

[ What is claimed is:] [1.] A measurement-while-drilling (MWD) tool for use during drilling of a wellbore having a longitudinal axis in a formation having a reflecting interface, comprising:(a) a tool body;(b) a plurality of spaced apart transmitter arrays carried by the tool body, each said transmitter array containing a plurality of spaced apart transmitter elements circumferentially disposed about the tool body, each said transmitter element adapted to propagate acoustic energy into a formation surrounding the wellbore;(c) at least one receiver axially spaced apart from the plurality of transmitter arrays on the tool body, said receiver detecting acoustic energy traveling through the formation in response to the acoustic energy transmitted by said transmitter elements; and(d) a processor, said processor selectively activating a plurality of the transmitter elements to focus acoustic energy into the formation in a selected direction towards the reflecting interface and processing the responses of the receiver to determine a parameter of interest.