Oil Country Tubular Goods
Drill pipe, casing and tubing - the primary oil field tubulars - fail in a variety of ways. Determination of the heat treated condition and the resulting mechanical properties affect the useful lifetime of tubular members. Study of the fracture surfaces, microstructure and accurately determining the failure modes are important elements of evaluating these failures. Hundreds of failures have been analyzed in our laboratory.
Parted casing strings frequently result from connection (coupling) failures. Poorly machined thread forms or perhaps incorrect heat treatment induce the problems. Over- or under-made casing/coupling connections may also induce premature failure.