Investigation of API 8 round casing connection performance-Part III: Sealability and torque

Journal Article · Thu Mar 01 04:00:00 EST 1984 · J. Energy Resour. Technol.; (United States)

DOI:https://doi.org/10.1115/1.3231010· OSTI ID:6489958

Asbill, W T; Pattillo, P D; Rogers, W M

The performance of the API LT and C 8 Round casing connection is investigated using 7-in.-29-lb/ft pipe size. An earlier paper showed that the finite element method was applicable for analysis using both a threaded and an unthreaded model. It also investigated the effects of various thread tapers and external loads on connection hoop stresses. It also evaluated maximum assembly interference based on an assumed criteria. This paper addresses connection sealability based on contact pressure. Geometric end effects are found to be significant in the unthreaded model. Sealability in the middle portion predicted by hand equations is shown to be reasonable. The threaded model shows that tension reduces sealability by disengaging thread stab flanks. Assembly forces are analyzed and, along with the test results, are used to find an equation for torque. The effects of thread taper variations, tension, and pressure on torque are shown.

• Research Organization: Harry J. Sweet and Associates Inc., Houston, TX
• OSTI ID: 6489958
• Journal Information: J. Energy Resour. Technol.; (United States), Journal Name: J. Energy Resour. Technol.; (United States) Vol. 106:1; ISSN JERTD
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420206* -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
EQUATIONS
FINITE ELEMENT METHOD
FORECASTING
GEOMETRY
JOINTS
MATHEMATICAL MODELS
MATHEMATICS
NUMERICAL SOLUTION
PERFORMANCE
PRESSURE DEPENDENCE
SEALS
SIZE
STRAINS
STRESSES
THREADED JOINTS
TORQUE
WELL CASINGS