Patent ID: 9581715
Date: 2017-02-28
CPC Classifications: E21B,G01V,G10K

Claim:
1. An apparatus for investigating a subsurface volume, comprising: an enclosure configured to be conveyed along a wellbore formed through the subsurface volume; an acoustic transducer disposed in the enclosure and generating acoustical signals; an electronics assembly disposed in the enclosure and controlling the acoustic transducer; and a lens assembly disposed in the enclosure and next to the acoustic transducer, the lens assembly being positioned to receive the generated acoustical signals from the acoustic transducer, the lens assembly being formed of a plurality of cells, each cell formed as a column oriented transverse to a direction of travel of the acoustical signals, each cell having a hub, a plurality of spokes radiating from the hub, and a plurality of fingers circumferentially distributed around the hub, wherein the hub, spokes, and fingers are oriented to cause the acoustic waves to travel at a different speed in each of three orthogonal directions, and wherein the lens assembly is further positioned to direct the acoustic waves into the subsurface volume.