Overview of the Seismic Reflection Industry

The seismic reflection industry can be divided into three main sections : data acquisition , data processing and data interpretation . These incorporate not only areas of technique, but also of business activity and of employment: 

? Data acquisition is a difficult operation on both land and sea. It requires a lot of skill and experience on the part of operating personnel and so, like much of the technically difficult operations in the oil business , is placed in the hands of specialist contractors . Firms such as Schlumberger Geco-Prakla, Western Geophysical , Petroleum Geo-Services (PGS) and Compagnie Generale de Geophysique (CGG) provide data acquisition and processing services and may also provide specialist interpretation of the results . However , most interpretation is handled by the client oil companies or specialist consultancies. The contractors may undertake to survey specific areas exclusively for oil-company clients – so-called proprietary surveys. They may also initiate non-proprietary or speculative surveys in areas that they think will be of interest, make interpretations of them and attempt to sell them to oil companies. Contractors are at the forefront of the research and development of new techniques in both acquisition and processing . They employ mostly physicists , geophysicists, engineers, computer scientists and mathematicians, with some geologists. 

? Data processing is normally handled by the same contractors who carry out acquisition, with the addition of some smaller firms who may focus on particularly advanced processing techniques. They all employ a similar mix of people. 

? Data interpretation is mostly handled by the client oil companies, who employ both geophysicists and geologists as seismic interpreters. Most companies have moved away from workgroups based on skills (‘Geology Department’) to groups based on projects (‘Tertiary Sand Plays’) or based on assets such as individual fields (‘Schiehallion team’). As a result, there is much more emphasis on the integration of geological/geophysical data with other data sets, such as those of the reservoir engineer, and all geoscientists have to know quite a lot about what the others in the group are doing. 

The petroleum industry is by far the biggest spender on geophysical surveying , spending about five times the total spent on all other applications such as minerals , engineering and research . Most of the expenditure goes on seismic reflection surveys and the total length of profile surveyed in a year is well over one million miles. About a third of that is on land and two-thirds at sea.