An Overview of the DISPS Development Programme

Abstract

ABSTRACT The paper out1ines objectives and concepts of BP Exploration's DISPS Project development programme, which is developing diverless subsea production technology for 350-750 metres water depths. The principal systems, subsystems and components which have been developed and tested are introduced and their inter-relation explained. The whole programme is overviewed, the experience gained from the extensive test programme outlined, and conclusion and lessons learnt summarised. INTRODUCTION DISPS is the acronym for BP Exploration's Diverless Subsea Production Systems Project, a deepwater subsea technology development programme, which started in 1985. Its objective is todevelop diverless subsea production technology and gain confidence in the principles, equipment and techniques that BP would use to exploit an oil or gas discovery in water depths up to 750m, such as would be encountered west of the Shetland Islands to the north of Scotland, United Kingdom. Two phases were foreseen when the Project commenced. The first phase consisting of major engineering design, development and testing of components and system testing is largely complete. The timing for the second phase, namely prototype application of the developed technology in diver accessible depths to gain operating experience, isdependant on the exploration programme and the actual future application in deep water. This paper will introduce and overview the principal systems and subsystems which have been engineered and tested to date. These are described in further detail in the complementary DISPS papers which follow. STATEMENT OF REQUIREMENTS When the DISPS Project Team was formed in early 1986 its first task was to crystallize the previous studies and reviews into an agreed techno1ogica1 package for the Statement of Requirements (SOR). This document set out BP Exploration's requirement as sponsor of the development programme, and to ensure that it adequately addressed BP's business needs the SOR was approved by a Steering Committee of Seni or Managers from several departments within BP Exploration and BP Engineering. In preparing the SOR the Project consciously narrowed the scope of work to fit available resources and timeframes guided by a perceived priority list of technology gaps. The Project also acknowledged that the SOR would be a snapshot of BP's perception as of mid 1986. and included sections of work in the SOR to help with future reviews of the work programme. The SOR, the Project's reference book, summarised the background and detailed the objectives. It set out the design premises and philosophies, described the concept used as a basis to implement the programme, and it formed the technical basisfor the first few engineering study contracts. The concept of DISPS being an enabling technology was promulgated In order to closely focus the programme the technology development was limited to subsea facilities and surface equipment to handle them, flowlines and umbilicals and their subsea terminations. STUDIES AND CONCEPTUAL DESIGNS The SOR was taken as the basis for studies of the major technology areas, and preparation of conceptual designs.