Velocity profile accuracy in depth prediction in a Texas Gulf Coast area has been statistically estimated by two methods: 1) a comparison of profiles to well surveys; 2) a study of errors in marker horizon depth estimates made in wildcats prior to drilling and in wells that had already been drilled. Both methods point to an accuracy of 1 to 2 percent in 80 percent of the samples at depths ranging from 5000 ft to 12,000 ft. Accuracy falls off fairly rapidly below 12,000 ft, but 50 percent of the samples still exhibit an accuracy of 2 percent or better at 15,000 ft. This accuracy is attributed to the two-mile spread lengths used, the overall good quality and density of the data, and to the moderate velocity range, 7000 ft/sec to 11,000 ft/sec.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page of Depth prediction from velocity profiles on the Texas Gulf Coast
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.