Stress analysis aids selection of casing and tubing for sour-gas environments

Journal Article · Mon Oct 26 04:00:00 EST 1981 · Oil Gas J.; (United States)

OSTI ID:5474185

Crusco, J

The most significant problem presented by deep drilling is the need for a casing and tubing string that can resist the high formation pressures found at great depths. Complicating this design challenge is the frequent presence of sour gas in deep wells, which can cause sulfide stress cracking of steel components. Given the critical function of tubing and casing connections and the unique pressures affecting them, a stress analysis of the connections becomes an important tool in string design for deep, sour-gas wells. One easy method of stress analysis uses Lame stress formulas and the shrink-fit-cylinder theory to calculate circumferential (hoop) stress in a thread interference connection. In critical wells, premium connections that use two-step, cylindrical, non-interference threads or other stress-reducing mechanisms are better alternatives than the conventional API and other tapered, threaded connections that rely on thread interference for sealing.

• OSTI ID: 5474185
• Journal Information: Oil Gas J.; (United States), Journal Name: Oil Gas J.; (United States) Vol. 79; ISSN OIGJA
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030300* -- Natural Gas-- Drilling
Production
& Processing
DRILLING
NATURAL GAS WELLS
PIPES
STRESS ANALYSIS
WELL CASINGS
WELL DRILLING
WELLS