RT Journal Article SR Electronic(1) A1 Le Vay Kriger, R.A. A1 Mokhtari, M. A1 Ireson, D.YR 1999 T1 The evaluation and design of a sea-bed 4C survey in the Brage Field using VSP data JF First Break, VO 17 IS 2 OP DO https://doi.org/10.1046/j.1365-2397.1999.00700.x PB European Association of Geoscientists & Engineers, SN 1365-2397, AB The arrival of commercial sea-bed recording systems has led to a recent rapid growth in sea-bed shear seismic acquisition. The data acquired, particularly in the North Sea, thus far have generally been of high quality. Sea-bed shear seismic acquisition is now becoming an accepted technique for `seeing' through gas, for lithology prediction and for differentiating between lithology and fluid amplitude effects. As the processing and analysis of such data become more secure it is certain that improved resolution, improved imaging and improved reservoir characterization through the availability of additional parameters will result in most cases. The ability to predict whether mode-converted shear surveys will provide a solution to a particular problem before acquisition commences is of great value. Such studies will also establish the best parameters for the acquisition, processing and imaging. In many offshore fields, particularly in the North Sea, a great deal of rig-source, deviated well VSP data exists in Oil Company files. Much of these data are recorded using threecomponent geophones and therefore characterize the complete elastic wavefield, including mode-conversions, as generated and propagated around the vicinity of the well location. Other types of VSP geometry such as walkaways, fixed offset source and vertical well and walkabove configurations also contain information with regard to the mode converted shear activity and can be used for a similar purpose. This paper serves to show how such data are integrated with other available data to test the likely value of a sea-bed multicomponent survey in helping to resolve a defined problem. Also illustrated is the information that such a preacquisition study provides for acquisition design and processing parameter selection. , UL https://www.earthdoc.org/content/journals/10.1046/j.1365-2397.1999.00700.x