Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Box, R. Articles by Loren, D. Search for Related Content GeoRef GeoRef Citation

Excellent synthetic seismograms through the use of edited logs

Lake Borgne Area, Louisiana, U.S.

Harmony Graphics, Houston, Texas, U.S.

Les Maxwell

The Meridian Resource Corporation, Houston, Texas, U.S.

Dennis Loren

Loren and Associates, Houston, Texas, U.S.

Corresponding author: info@loreninc.com

The first 20% of the full text of this article appears below.

Information of great value for seismic processing and interpretation can be gleaned from synthetic seismogram ties and their associated well-based wavelet extractions, but only if the well data are excellent. If the well data are not very closely and correctly edited, wrong conclusions are likely.

Synthetic seismograms often fail to tie with surface seismic data because they are made from well logs distorted by borehole washouts, formation damage, tool miscalibrations, digitizing or database errors, and many other difficulties. These difficulties may be overcome by editing the logs, especially if the editing method is multizone and multiwell, and uses regression rather than neural nets or other curve-fitting techniques. Box and Lowrey show that one such method, called log purification (described below) detects most of the errors in sonic and density logs, and replaces them with realistic computed values, bringing them into harmony with velocities measured by check-shot surveys. Here we show that logs edited in the same manner produce synthetic seismograms which match the seismic data, allowing us to analyze the true phase and frequency content of the seismic data.

This paper compares a South Louisiana well seismically analyzed in its recorded form to the same well analyzed in its edited form. The recorded logs contain enough "noise" to blur the wavelet extraction process, making it impossible to conclude much about the seismic data processing. One could incorrectly conclude from the results that the seismic polarity is reversed. The edited logs contain very little noise, making it easy to create robust wavelet extractions and excellent synthetic seismograms, yielding clear, valuable insight about the wavelet processing of the seismic data.

	Area of study

 
The well used in this study is the Texaco 1 SL 9595 OKC. It is located east of New Orleans, Louisiana, on the southeast shoreline of Lake Borgne in St. Bernard Parish . . . [Full Text of this Article]