Two main areas of offshore activity are addressed in this book: Site investigation on assessment; and Applications and foundation engineering. The 37 contributions from a wide ranging group of international experts, are resulting from the Offshore Site Investigation and Foundation Behaviour Conference, London, U.K., September 1992. Adequate determination of site conditions can only be achieved by the integrated approach of using geological, geophysical and geotechnical data. Developments in data acquisition techniques are illustrated through case histories in the section on Geotechnical Sampling and Testing. In the section on Advanced Interpretation Techniques and Integrated Interpretations the state of the art of these topics is also illustrated by case histories. A review of foundation behaviour is presented in the section on Gravity Foundations, Foundation Performance Monitoring, Piling Research and Design Criteria. These topics are illustrated in the light of field experience and recent research, in particular that involving full-scale tests and monitoring. This book provides many illustrative figures and much pertinent information to exploration and marine geophysicists, petroleum and offshore engineers and for researchers working these fields.

Ocean engineering is generally considered to be concerned with studies on the effects of the ocean on the land and with the design, construction and operation of vehicles, structures and systems for use in the ocean or marine environment. The practice of engineering differs from that of science in both motivations and objectives. Science seeks understanding of the principles of nature in terms of generalizations expressed as laws and classifications. Engineering seeks the application of knowledge of the physical and natural world to produce a benefit expressed as a device, system, material, and/or process. From the standpoint of the financial sponsors of an engineering project, the ideal approach is one of minimal risk in which only proven knowledge, materials and procedures are employed. There is frequent departure from this ideal in anticipation of the increased benefit expected from a large increase in performance of a structure or device. The process of acquiring this new capability is engineering research. Historically, ocean engineering developed with the application of engineering principles and processes to the design of ships and, later, to the machinery that propels them. In most societies, naval architecture and marine engineering are recognised as the origin of ocean engineering. In fact, the design of a ship constitutes the original systems engineering programme involving hydrodynamics/fluid flow, structural design, machinery design, electrical engineering and so on as well as requiring knowledge of the ocean environment (waves, corrosion, etc.).

Today western nations consume annually only a small percentage of their resources from the sea, despite the proclamation of Exclusive Economic Zones (EEZ) by many. In contrast, most Pacific Basin Countries obtain more than a quarter of their annual needs from the ocean. Determination of greater rewards from the development of marine resources is markedly inhibited by the limited technical abilities available to locate and assess them. Knowledge of Exclusive Economic Zone resources is schematic and generalised, and a detailed understanding of the geology and processes relating to the economic use of the seafloor is both fragmentary and very basic. Technology for mapping the mineral resources of continental shelves and ocean areas, except in active offshore hydrocarbon provinces, has been largely developed in pursuit of scientific objectives and competence to rapidly appraise economic potential is limited. Similarly, the capability to characterise and evaluate the other resources of the seas is rudimentary. The development of ocean resources will become increasingly urgent as the growth of the world population and the depletion of land reserves combine to enhance demand. Also, increasing environmental constraints will limit the availability of traditional land-based resources; nevertheless, new offshore development must proceed in a manner whereby the marine environment is not plundered but protected and conserved. The challenge to develop ocean resources with responsible environmental stewardship will require greater leadership than the development of the technologies of exploitation.

Ocean engineering is generally considered to be concerned with studies on the effects of the ocean on the land and with the design, construction and operation of vehicles, structures and systems for use in the ocean or marine environment. The practice of engineering differs from that of science in both motivations and objectives. Science seeks understanding of the principles of nature in terms of generalizations expressed as laws and classifications. Engineering seeks the application of knowledge of the physical and natural world to produce a benefit expressed as a device, system, material, and/or process. From the standpoint of the financial sponsors of an engineering project, the ideal approach is one of minimal risk in which only proven knowledge, materials and procedures are employed. There is frequent departure from this ideal in anticipation of the increased benefit expected from a large increase in performance of a structure or device. The process of acquiring this new capability is engineering research. Historically, ocean engineering developed with the application of engineering principles and processes to the design of ships and, later, to the machinery that propels them. In most societies, naval architecture and marine engineering are recognised as the origin of ocean engineering. In fact, the design of a ship constitutes the original systems engineering programme involving hydrodynamics/fluid flow, structural design, machinery design, electrical engineering and so on as well as requiring knowledge of the ocean environment (waves, corrosion, etc.).

Today western nations consume annually only a small percentage of their resources from the sea, despite the proclamation of Exclusive Economic Zones (EEZ) by many. In contrast, most Pacific Basin Countries obtain more than a quarter of their annual needs from the ocean. Determination of greater rewards from the development of marine resources is markedly inhibited by the limited technical abilities available to locate and assess them. Knowledge of Exclusive Economic Zone resources is schematic and generalised, and a detailed understanding of the geology and processes relating to the economic use of the seafloor is both fragmentary and very basic. Technology for mapping the mineral resources of continental shelves and ocean areas, except in active offshore hydrocarbon provinces, has been largely developed in pursuit of scientific objectives and competence to rapidly appraise economic potential is limited. Similarly, the capability to characterise and evaluate the other resources of the seas is rudimentary. The development of ocean resources will become increasingly urgent as the growth of the world population and the depletion of land reserves combine to enhance demand. Also, increasing environmental constraints will limit the availability of traditional land-based resources; nevertheless, new offshore development must proceed in a manner whereby the marine environment is not plundered but protected and conserved. The challenge to develop ocean resources with responsible environmental stewardship will require greater leadership than the development of the technologies of exploitation.

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.