Author(s): K. -U. Evers; P. Jochmann; W. Kuehnlein
Linked Author(s):
Keywords: No Keywords
Abstract: The Offshore Kazakhstan International Operating Company (OKIOC) has started exploration wells in the North Caspian Sea. These first wells target the ultra-shallow water Kashagan formation. The drilling operation is being performed by Rig 257, a modified swamp barge. The rig is 84.5 m long, 52.7 m wide with a draft of about 2.15 m. The barge will be installed on a pre-fabricated underwater berm made of limestone. The largest horizontal loads will be caused by sea ice, which occurs in the North Caspian Sea between November and April. In order to reduce the ice loads on the barge, inclined outer-walls have been designed to cause an initial failure of the ice by downward bending. Ice deflectors have been installed around the barge in order to prevent overriding of the barge by rubble ice. Ice model tests, with two differently scaled models have been carried out in the Large Ice Model Basin of HSVA in order to measure the vertical and horizontal ice loads acting on the ice deflector, barge, berm, and on the breasting piles in front of the barge. In addition to the load measurements the rubble pile-up process in front of the barge was investigated. The results of the model tests have been used to determine the design ice loads for the full-scale structure.
Year: 2000