Testing of Gas-Tight Joints Under Extreme Conditions

Abstract

ABSTRACT During production from high-pressure gas wells, the casing and tubing strings are subjected to a combination of extreme loads due to internal pressure, axial loads, temperature, and sometimes bending. All loads may vary greatly during production cycles or production and shut-in periods. Testing facilities and programs are needed for evaluating the functional behavior of pipe connections during load and temperature cycles simulating actual field conditions. The paper describes a complete testing set-up with high capacity and flexibility. The unit allows internal gas pressure up to 3500 bar, axial loads of 3000 kN, bending loads of 3600 kN, and temperatures up to 185°C at the joint. Furthermore, the paper presents results derived from a large number of tests on tubing and casing of various sizes,grades and joints, including 2–3/8" tubing and 10-3/4" heavy wall casing.