Dr C P Ellinas Advanced Mechanics & Engineering Ltd Major advances have been achieved in recent years in subsea pipeline design and installation. Inspection, maintenance and repair have also received much attention. The development of marginal fields has brought with it special problems, which have necessitated novel methods and solutions. In the meanwhile interest in the development of deepwater fields continues with the development of new technology. This Conference has placed emphasis in addressing developments in pipeline technology under four main headings: pipeline/seabed interaction; flexible pipelines; pipeline design, fabrication and installation; deepwater applications. Advances in North Sea technology over the last few years have been concerned mostly with marginal fields, small diameter pipelines and new materials, which are well covered in the first three topics. Economic development of marginal fields requires processing of oil and gas to take place not at the wellhead but at existing facilities, usually some distance away. Hydrocarbons are thus often transported at high pressure and temperature in small diameter pipelines, which need to be protected through trenching. However, such operational practice has brought to the fore a problem that in the past was of little concern namely, upheaval buckling.

Edited by the Society for Underwater Technology, this text covers advances in subsea pipeline engineering and technology. Topics covered include changes in the industry, high pressure/high temperature, design, construction/installation and operations and maintenance.

Aspect '94 is the most up-to-date and comprehensive assessment of the present and future of the pipeline systems industry. It comprises papers from leading experts in all areas of pipeline engineering and technology. As this book shows, the last few years have seen great strides forward in the field of subsea pipelines. Deepwater pipelines, long distance pipelines and complex systems transporting hydrocarbons and fluids to and from marginal field subsea wellheads and templates are all being implemented without significant problems. The pace of progress continues to accelerate in the subsea industry, and the scope to make further improvements is constantly being explored. Operators, consultants, suppliers and contractors are all researching, developing and testing new techniques and ideas.

The three parts of this volume - Technical Refinement; Technical Innovation; and Project Management and Risk Minimisation - reflect the areas of opportunity for improved cost effective techniques for exploration and production of oil and gas in the North Sea and worldwide. The book is indispensable for engineers and scientists interested in the latest advances in technology and resource management that will reduce costs and continue to enhance the safe exploration of oil and gas resources. This volume comprises a selection of contributions presented at the International Conference Subsea International '93, held 28--29 April 1993 in Aberdeen, U.K.

Shallow Gas determination, prior to drilling, is carried out using 'Engineering Seismic' survey methods. Seismic acquisition data quality is fundamental in achieving this objective as both the data processing methods and interpretation accuracy are subject to the quality of the data obtained. The recent application of workstation based data analysis and interpretation has clearly demonstrated the importance of acquisition data quality on the ability to determine the risks of gas with a high level of confidence. The following pages summarise the 5 primary issues that influence acquisition data QC, suggests future trends and considers their potential impact. The primary issues covered in this paper are: A. Seismic B. Positioning C. QC Data Analysis D. Communications E. Personnel 90 SAFETY IN OFFSHORE DRll.LING FIELD QC ...................... PRIMARY COMPONENTS COMMERCIAL TECHNICAL 1 OPERATIONAL FIGURE 1 HYDROSEARCH The often complex influences of Technical, Commercial and Operational constraints on the acquisition of high quality data require careful management by the QC supervisor in order to achieve a successful seismic survey data set. The following pages only consider the Technical aspects of QC and assume that no Commercial or Operational restrictions are imposed in the achievement of optimum data quality. It is noted however, that such restrictions are frequently responsible for significant compromise in data coverage and quality during routine rig site surveys.

The three parts of this volume - Technical Refinement; Technical Innovation; and Project Management and Risk Minimisation - reflect the areas of opportunity for improved cost effective techniques for exploration and production of oil and gas in the North Sea and worldwide. The book is indispensable for engineers and scientists interested in the latest advances in technology and resource management that will reduce costs and continue to enhance the safe exploration of oil and gas resources. This volume comprises a selection of contributions presented at the International Conference Subsea International '93, held 28--29 April 1993 in Aberdeen, U.K.

The concept of using flexible, reelable pipe to transport liquids, gases, and vapours is not a new one. As early as the 1940s a steel braided elastomeric pipeline was developed for the Allied Forces in order to transport fuels to support the Normandy Beacheads. In fact, the longest flexible pipeline ever constructed is likely to be that laid across the English Channel as part of 'Operation Pluto'. The methodology used to handle and instal such pipe is also not new. Ellis (1943, London) in an early patent specification identifies three basic objectives for a flexible pipelining method. These are: prefabrication of the pipe onshore; coiling of the pipe on suitable drums or reels; and using such reels to lay pipe from anchored or motorised barges. The design concept for flexible pipe is also not a new invention given that flexible hoses and umbilicals have been in service for more than sixty years. A break-through was however achieved by the French Institute of Petroleum in the early 1970s when they developed an improved steel reinforced pipe structure having a high axial loading capaci ty which utilised corrosion and hydrocarbon resistant polymers to extend pipe service lifetime. This early pipe design utilised established cable making techniques to apply steel armour and axially and radially reinforce alternating layers of polymer sheaths. The pipe was primarily developed as a flowline for use in static seabed applications.