Recently more and larger jackets have been installed in the Asia Pacific area, the Liwan3-1 central processing platform (CEP) platform is the largest offshore platform in Asia with a jacket load out weight about 32,000mt and with a topsides design weight about 44,000mt. And jacket foundation pile is the largest one in the world with 4×ø108" dia. vertical skirt piles at each jacket corner leg. Each pile is at 158 meters in length with 135 m design penetration depth and dry weight of 755mt. In the pile design, major contents were performed as following:

  1. pile axial capacity check;

  2. Pile lifting strength check;

  3. stick-up stability calculation;

  4. pile drivability;

  5. fatigue analyses;

  6. pile shoe buckling and grout connection, etc.

In the installation of large diameter steel piles, the initial penetration depth shallow and run pile will increase the risk of offshore construction. At present, there are no mature methods of calculating the soil resistance. Through the study on soil of this area, we found that the main problem is the estimation of pile end resistance is not accurate. This paper study on influence factors for length of run pile in initial penetration condition and driving process are discussed. Combining with field dynamic monitor test data, the new evaluation methods for soil resistance are present. Such approach can well fit the real situation for this region in South China Sea.

Keywords:
subsea system, installation, upstream oil & gas, pile design, bearing capacity, end bearing, penetration depth, skin friction, pile self penetration, resistance
Subjects:
Offshore Facilities and Subsea Systems, Platform design, Installation equipment and techniques
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2014. Offshore Technology Conference
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