Automated Seismic-Well Tie Using Dynamic Time Warping and Optimal Interpolation

Abstract

Seismic-well tie is a crucial process to correlate subsurface information from well logs and acquired seismic data. Traditionally, a manual seismic-well tie is conducted based on the interpreter's visual pattern recognition, which is subjective, time-consuming, and may lead to unrealistic velocity distortion. This paper presents a new method to automatically tie seismic to well using Dynamic Time Warping (DTW) and Optimal Interpolation (OI), to save man-hour and to obtain a more reliable time-depth relationship. To produce a better tie, we use DTW to seek the appropriate amounts of time stretching and squeezing to match the synthetic and actual seismic. Then, we balance the rigid pattern matching of DTW by using OI to smooth DTW results and constrain changed rock velocity to be within physical bound. The invented technique has been used to tie seismic to six exploration wells in the Gulf of Thailand. The results from the automated method are then compared with the manual method. For all wells, resulting synthetic-seismic correlations from the automated well tie are higher than the manual method by 1.6%-14.9%. Applied time shifts from the automated and manual methods are then compared. Notably, time adjustment correlations between the automated and manual well tie are considerably high, around 72%-85%, suggesting that both methods yield similar outcomes, yet the automated well tie gives a slightly higher match between tied synthetic and observed seismic traces.