Wireless downhole tool positioning control

摘要

For a free falling well tool sub having one or more pipe bore centering cages, a collapsible material cone secured inside of the centering cage half length with the cone base opening in the downhole direction restricts the rate of pipe bore fluid flow past the cone and thereby restricts the descent rate of the tool. The rate of descent may be regulated with fluid flow by-pass apertures in the sub. A collapsible material cone in a bore centering cage having a base opening in the up-hole direction may be used as piston to drive the tool sub along horizontal segments of a deviated well bore. Both cones may be used separately or together.

主权项

1. A free falling well tool comprising a pipe section having at least a pair of pipe section centralizing cages, one above the other along an axial length of said pipe section, each of said cages comprising a plurality of bowed spring elements distributed around said pipe section, said bowed spring elements having opposite distal ends secured adjacent surface elements of said pipe section, a substantial cone of flexible material disposed within and around said cage between surface elements of said pipe section and a bight portion of said cage with an apex end of one cone oriented in an up-hole direction and an apex end of another cone oriented in the down hole direction, a wall of said pipe section being penetrated by apertures therein above and below said one cone apex.