Installation of Fixed Steel Piles Platforms in Deep Water

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the SPE-European Spring Meeting 1975 of the Society of Petroleum Engineers of AIME, held in London, England, April 14–15, 1975. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. A fixed platform consists normally of:A substructure: a space frame of pipes welded together, called jacket or template.A pile foundation, to nail the substructure to the sea bottom.A deck construction over the substructure.Prefabricated units containing production and/or drilling equipment. With deep water is meant, depths of over 150 feet. Presently structures are being designed and fabricated for water depths up to some 500 feet.In water depths up to some 300 feet, the jackets weigh normally less than 6000 tons and may be transported and launched at location from specially designed launch barges. The load-out of such structures is usually done by sliding them from the fabrication site on a barge over a rail system with surfaces of steel or wood or teflon, overgrease.In greater water depths, the jackets usually weigh more than 6000 tons and up to 20,000 tons. Although launching of such huge structures is possible, they are usually built so that they will float, and are towed to location, and upended by a system of selected flooding of the legs.The piles for deep water structures vary from an O.D. of 36" to a maximum of 72",with wall thicknesses varying from 7/8"to 2 1/4".Penetrations vary from 100 feet to 350 feet depending on soil conditions and required bearings. Ultimate design loads on piles vary from 1500 tons to 5000 tons. If the piles cannot be driven to the penetration required to obtain the necessary design bearing, drilling out of the plug, or other means, like the patented Heerema "slip joints", to obtain more penetration, may be used. As a last ressort insert piles, pin piles or underreaming may be used. The first length is then driven to a practical penetration, usually with the use of a drilled pilot hole. Then a smaller diameter hole is drilled inside the first pile and well below of the tip of the pile, with mud circulation, to maintain the hole and grouted with a cement mix to obtain adherence to the walls of the hole.