Surface geochemistry in petroleum exploration / Геохимия поверхности в нефтеразведке

Initially, I approached this book with a certain trepidation. Forseveral decades, surface geochemistry has been a controversial subject when applied to petroleum exploration. Vertical migration is not a new concept, but the mechanism by which it occurs is still not clear. Quantifying all the different elements from the seal rock to the soil may be an insurmountable task, but we can identify, discuss, and interpret the principal ones. The majority of evidence has not come through laboratory or research investigation but by field
observation. Data from laboratory results and from fieldwork are often conflicting. Consequently, there have been steps backward and stumbles forward toward a clearer understanding. Difficulty in re-creating or duplicating conditions of vertical migration in the laboratory will continue to be a problem as we have not really identified all the essential parameters needed to facilitate vertical migration. Surface geochemistry is a valid tool and is not the ultimate "black box."* Every reasonable tool applied with objectivity will increase success and decrease failure. In petroleum exploration, we hope to achieve an above-average ratio of successes to failures. The view of exploration is like ajigsaw puzzle; every tool is a piece leading to a complete picture and a reward of finishing.
I began my career in the search for base and precious metal deposits; in mining, the concepts and applications of surface geochemistry have always been acceptable. When I was first employed in the petroleum industry, I was uncertain about the viability of surface geochemistry in view of the industry's ingrained concept of the integrity of the "seal" above the reservoir. However, I became convinced of the usefulness of surface geochemistry and questioned the absoluteness of the seal when I was working in an area where production is shallow (400 to 1200 ft). This area made the existing seismic methods untenable and uneconomic. Also, many of the existing data from these shallow wells were unreliable. I was able to utilize soil-gas and radiometrics with good results. But I was still skeptical about the claims of tremendous successes by various contractors. Unfortunately, many of these successes were related to existing fields. Over time, through association with several companies, I was able to try different surface geochemical techniques with varying results. The overall result was that when a surface geochemical anomaly was not present, there was a dry hole. It was clear, too, that there was very little scientific investigation into these methods.<...>