Jolliet TLWP Well Systems

Abstract

Abstract This paper cut lines the unique features of the Jolliet Project well Systems. same of these features are as a result of experience gained on the Hutton tension leg platform, while others came as a result of special condition relative to the Jolliet Project. The paper describes the systems starting at the drilling template, moves up the production riser to the surface support facilities and finishes with the internal completion. INTRODUCTION The well systems on the Jolliet Project Tension leg well Platform (TLWP) comprise the components of the production riser system. Full size tension leg platforms may have tensioned production, export and drilling risers. In the case of the Jolliet Project, all wells were predrilled and work over?s will take place through a 9-5/8 inch casing. Cot1segUently, there is no need for a drilling riser as no new drilling, apart from sidetracks cut of a cased hole, is anticipated. The export risers are flexible pipeline risers to minimize weight am tie-ins on the TLWP. The production riser system (Figure 1) consists of the sub sea wellhead which sits in the drilling template receptacle, lower riser connector, tapered joint, riser pipe, special top riser joint, wellhead, Christmas tree and tensioned. sitting inside the production riser is the internal tubing completion. WELL SYSTEM Components Long Wellhead Receptacles (Figure 2) one of the requirements of a TLP production riser system is to install the 30 inch wellhead vertically, as this in turn sets the verticality of the 18-3/4 inch high pressure housing. Anyl deviation from vertical in the high pressure housing has a detrimental effect on the fatigue life of the production riser. The long wellhead receptacle (15 feet) has reduced diameters at the top and at the bottom that restricts the 30 inch casing angle to I' when it is being run am the 30 inch wellhead housing to 0.5' when installed. This system may be used with jetted or dynadrilled casing. The receptacles form part of the well pods installed on the drilling template [1]. Because they do not serve as structural members, the receptacles were lightened with large, cut windows to reduce the in-place and lift weight of the well pods. Guide Posts (Figure 3) There are no permanent guideposts installed on the drilling template. The posts are removable and are installed each time a riser is run or drilling takes place. '1bey latch by means of their own weight into a receptacle and are released by a hydraulic tool that can be run on a FDV or on drill pipe from the surface.