SOLID PLUG OF RADIOACTIVE TRACER MATERIAL

摘要

A solid plug of material containing a radioactive tracer is adapted to engage a grinder for progressively grinding material from the plug at a selected rate and feeding the ground material to fracturing fluid being pumped underground. The solid plug comprises a hollow graphite tube filled with radioactive-labelled sand particles, these sand particles being resin-coated and being bonded together by the resin coating to form together with the graphite tube a solid plug.