Affiliation:
1. Department of Geophysics, Stanford University
2. British Petroleum, Britannic House, Moor Lane, London, England EC2Y 9BU
Abstract
The length of a seismic profile and the recording time available as input to migration govern simple equations relating dip observable on migrated profiles to the spatial location of the reflector. This relationship is important to exploration geophysicists seeking critical seismic dip and to deep crustal geophysicists examining the nature of the continental crust. A certain amount of the observed decrease of dip with depth, and the dip biasing on the edges of migrated sections, can be related to the size of the input, as shown in a real data example. Any further decrease in dip with depth may have geologic significance. To portray (image) up to 45‐degree dips at the target depth, 50 percent more time must be recorded and input to the migration as the two‐way migrated time of the target. The lead‐in (or step‐in) required on both ends of the line is the depth to the target. For 0‐ to 30‐degree dips to be present at the target depth, one‐sixth more time must be recorded and input to the migration; the lead‐in must be 65 percent of the depth to target. Crooked profiles complicate the migration: either linear segments of the profile are migrated separately (which drastically decreases the dip resolution obtained on the section as a whole), or the line can be “straightened” (projected onto a dip line) and then migrated as a unit [which assumes the target horizon is two‐dimensional (2-D)].
Publisher
Society of Exploration Geophysicists
Subject
Geochemistry and Petrology,Geophysics
Cited by
23 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献