Permafrost thaw-subsidence casing design

Conference · Thu Jan 01 04:00:00 EST 1976

OSTI ID:7117521

Mitchell, R F; Goodman, M A

Casing design for arctic wells requires estimates of maximum casing strains due to permafrost thaw subsidence. These maximum strains have been determined for the Prudhoe Bay Field by sensitivity studies with an analytical thaw-subsidence model which correlates with field test data. The sensitivity studies include the strain dependence on (1) thaw radius, (2) permafrost lithology as defined by layer thickness, layer separation, and layer depth, and (3) permafrost mechanical properties. The main conclusions from the sensitivity studies are that the effect of thaw radius and lithology can be bounded and that the significant dependence on mechanical properties can be isolated to one material parameter, the compressibility ratio of contiguous soil layers. At Prudhoe Bay, upper bound compressive strains calculated by sensitivity studies are about one-third of the allowable strain limit of 13-3/8 in., 72 lb. N-80 buttress casing.

• OSTI ID: 7117521
• Report Number(s): CONF-761008-70
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ARCTIC REGIONS
COMPRESSIBILITY
DESIGN
GROUND SUBSIDENCE
MECHANICAL PROPERTIES
PERMAFROST
POLAR REGIONS
SOILS
STRAINS
STRESS ANALYSIS
WELL CASINGS