In the article entitled “Ridgeway to delineate CO2 field, eyes Permian EOR” (OGJ, May 28, 2007, p. 41), the statement was made that none of the 26 wells has encountered oil or natural gas, which is incorrect.
After the first round of delineation wells, the cores from the wells in Arizona were sent to the Arizona Geological Survey in Tucson. Since High Plains developed and sold the St. Johns Prospect to Ridgeway, I was interested in viewing those cores, which I did, and I noticed an oil-stained dolomite on one of those cores, which both Steve Rauzi (Arizona oil and gas administrator) and I observed. Therefore, oil was encountered in at least one of the wells that has been drilled to delineate the St. Johns discovery.
From a historical perspective, Ridgeway Arizona Oil Corp. was formed because oil and combustible gas were expected, based on the Tenneco and Mae Belcher wells, which both encountered oil in the Supai. Furthermore, the CO2 and helium accumulation on the St. Johns anticline may be a gas cap with an oil rim. In any case, oil is present on the structure. Whether oil is present in commercial quantities remains to be seen.
Since the Supai dolomites have such high porosity, from 16% to 31% in the discovery well on the St. Johns anticline, the presence of oil in such a dolomite is important, not just as an “oil show” but as an oil show in a zone with excellent reservoir quality.
John B. Somers II
High Plains Petroleum Corp.
Boulder, Colo.
