Reliability of Jacket Platforms in Malaysian Waters Sensitivity Study using Pushover Analysis

Abstract—Issues regard to continued usage of aging jacket
platforms and Enhanced Oil Recovery (EOR) affecting the aged
fixed jacket platforms owned by PETRONAS in Malaysian
waters was studied. Pile buckling together with lateral soil failure
and lengthy/ monotonous reliability analysis were identified as
the core research issues related to the problem statement. SACS
software was used on existing jacket platform structural model to
carry out pushover analyses. Reserve Strength Ratio (RSR) was
obtained through different combinations of dead, live, and storm
loads. It was found that live load combinations had insignificance
on the RSR value compared to variation in storm directions. RSR
values from directional loads and resistance are very much
volatile and significant. The response of the pile foundation to the
environmental load is strongly affected by pile soil interaction.
Since the development of p-y curve represents the pile foundation
and soil structure interaction, it was used to model the soil
resistance to the pile movements and the results obtained were
analyzed. Collapse analysis with PSI yields lower RSR compared
to an analysis without PSI. Inclusion of PSI (pile soil interaction)
increased the RSR value in the range of 5.6% to 50.1%. A trend
called slender column and truss system effects were introduced
for the pushover analysis with and without PSI, respectively.
Sensitivity study was in agreement with failure mechanisms
experienced in the pushover analysis.
Index Terms — Reliability, Jacket Platforms, RSR, p-y curve,
pile-soil interaction.