Zhao Dong Oilfield is located in the shallow water area in Bohai Bay with 2.4-metres average chart sea level and 4.4-metres maximum height of tide. Under such special condition, the installation of the platform requires great difficulty and risk. The drilling platform of Zhao Dong Oilfield is a fixed platform and weighs 6,200 ton. To make sure of the successful installation at extremely shallow water area the Strand Jack lifting was applied together with making use of tide level and dredging work. The platform offshore installation was completed on October 27th, 2002. This paper introduced the analysis of platform installation conditions, proposal selection and installation procedures.
Zhao Dong Oilfield is the first project that PetroChina cooperates with international oil companies to perform crude oil exploration and development in offshore area and achieve commercial production. The drilling platform installation was performed in the first phase of the project and completed by 27th October 2002. The topside consists 5 layers of decks with the overall highs of 19 meters. The size of largest deck is 64 meters time 49 meter and the gross weight of the platform is 6200 ton. The main facilities on the platform are drilling rig with accessorial equipments, well bay area, diesel and water storage tanks with accessorial pumps, control room, ESP building, 4 floors living quarter, heli-deck, fire fighting and life saving equipment. The plane gravity center of the platform is approximately on the geometry center. Since it is very shallow water area the topside is designed to be supported by eight pile legs only. The pile leg diameter is 1830 mm and its total length is 96 m with 80.62 m in mud. The piling of the eight supporting legs had completed previous to the installation of the platform.