A Lesson in Seismic Data Acquisition<br>Smith River Valley, Montana

In 1979 I had the exciting responsibility of supervising the acquisition of the first seismic data ever shot in the Smith River Valley in Montana. What a thrill for a young geophysicist out to prove his worth! Armed with books on "geophone array responses" and "seismic data acquisition", I headed for the mountains, full of confidence, knowledge, and enthusiasm.
The tiny town of White Sulphur Springs was our headquarters. It sits in a broad valley of cattle pastures and farmland surrounded by beautiful mountains. Our Pac West crew was experienced in mountain seismic acquisition and included a hardy seventy-year old man who was a wood-carver, and two women who liked to work bare-chested in the remote mountains along, with their proud and protective male counterparts who encouraged that feminist experience.
Dick Poulson, a delightful bear of a man from Salt Lake City, was the field geologist. He and I were the "technical team", while jovial permit agent Lee Crawford made good buddies of the local ranchers, to whom he had to explain what seismic was. They treated us to an incredible fishing experience and showed us an arsenal that was ready to take on the Communist threat looming from Canada.
Upon arrival of the crew, I directed the layout of the spread for noise tests, determined to find absolutely the best geophone array possible to cancel all the noise that we would find. I wanted the first data in the valley to be the standard by which all later data would be shot. Shot holes of various depths were loaded with shots of various sizes, and different patterns were laid out along a long seismic line. All was made ready for the big day.
We spent the entire first day testing. The first shot produced total noise, as did the second, third and fourth. Total noise made no sense. Things were changed. More noise. More changes, and still more noise. Disappointment grew into despair. My seismic education under Dr. Smithson at Wyoming and my geophysical training at Exxon had not considered the possibility of unequivocal failure. I headed for one of White Sulphur Springs? several bars, bewildered and stung.
Dick Paulson came out of the mountains and found miserable me. It must have been clear that I did not want to speak to anybody, but he was not the type to hold anything back. He said, "Hey, from up on the mountainside I could see you shooting that seismic line, walking around like little ants. But why did you lay the line out along the surface fault?"
"What are you talking about?" I replied. He pulled out his maps. "From up on the mountain, you can see the expression of a surface fault running through here and you were laid right along it." Despair turned to hope that maybe the fault was dispersing all the energy.
The next day we rotated the line 90 degrees and, sure enough, we got data- primaries, multiples, and noise trains. Glorious noise trains. I could put my book learnin? and trainin'' to work. The first seismic data in the Smith River Valley was useable, and eventually a well was drilled. (It was a dry hole, but that must have been the geologist?s fault!)
How unlucky we had been to lay the line right along the fault. (It probably must have looked like a good place to run a straight line.) How lucky we were to have a knowledgeable geologist on the mountain- and communication. Lessons in work, luck, and expanded thinking.
There is an epilog to this story, another lesson learned. On the second day, after examining the data and studying the array responses, I determined that a particular pattern of geophones arranged in a "star" would cancel most of the noise. So the juggies were gathered, and I demonstrated how to lay out and maintain the star. Everyone seemed willing and off they went, arranging and stomping the phones. I followed. The first array was excellent, the second less so, the third was a bit wobbly, and then real deterioration set in. By the sixth station the star design pattern was unrecognizable. The "geophone array response" book might be good science, but in real life, with real juggies, the KISS rule reigns.