R. A. Broding
Amoco Production Research
Tulsa, Oklahoma
ABSTRACT
Volumetric Seaming (V.S.) of a borehole is the process of measuring the physical response of rock surrounding the borehole by seaming in the lateral, vertical, and azimuthal direction. To allow scanning in the above three directions, the energy source and detector must be capable of being focused or a beam formed and scanned. In our sonic scanning as many as 512 data points are sensed by seaming outward from the borehole for each of 512 horizontal scans around the borehole (one rotation) for each of 30 rotational scans per foot of borehole or a total of 8.6 million data points per foot of hole depth. Because of the large amount of data , a practical method for comprehending this response is to create images or pictures of the rock. Two-dimensional rectilinear plotting with gray scale for a third dimension is used, as well as three-dimensional representations using polar seaming and scrolling of the image to form an isometric solid of revolution. Additional physical measurements being considered include acoustic or sonic energy, electric and magnetic fields and radioactive emission. Logging parameters would include the acoustic caliper, specific acoustic impedance, density, velocity, electrical conductivity, and most present day logging parameters. This paper describes the use of the sonic reflectance and transient time to produce imaging by the V.S. concept.