Something to read while we wait for the outcome I came across this interesting pdf article written in 1956 - The Guidebook to the Geology of the Raton Basin, Colorado - it's in reference to the land around BNL's land - it's a really interesting read (as links sometimes don't work on HC, I've copied and pasted the information below) - cheers MC.
THE RATON BASIN, COLORADO LAS ANIMAS COUNTY, COLORADO by Joseph R. Clair and B. B. Bradish Geological Consultants, Denver, Colorado
INTRODUCTION The Model Dome gas field comprises parts of Twps. 29 and 30 S., R. 60 W., in Las Animas County, Colo. The field is on the Model anticline which extends some 16 miles in length and five to seven miles in width from Twps. 28 to 31 S., Rs. 59 and 60 W. The field is noted for its high helium content and at present is controlled by the U. s. Government as a helium reserve,
STRATIGRAPHY The outcropping rocks range from the Fort Hays limestone member of the Niobrara formation to the upper part of the Dakota sandstone. The thickness and gross lithologies of this section are shown in the accompanying columnar section from Bass (1947). No sample data on the subsurface section are available but from Bass (1947), correlations of drillers logs show the subsurface section to be much like that at Garcia below the Dakota sandstone and, hence, the columnar section is applicable for both areas. The Glorieta (Lyons) sandstone is the producing horizon and no mention is made of any shows at any other horizons. Inasmuch as the wells were all drilled with cable tools it is probable that no shows were encountered. The pay horizon has been variously correlated with Triassic (Santa Rosa) and Jurassic (’VVingate) rocks by earlier workers, but on the basis of the writers’ work, Bass‘ correlation seems most logical. It is of interest that the marker beds of the Denver basin are present also in the Model area. The Lincoln limestone member of the Greenhorn limestone is the “brown” limestone of the Denver basin and the bentonite bed just above it is the bentonite marker of that area.
STRUCTURE The Model anticline, as shown on the accompanying surface structure map modified after Bass (1947), is in general a slightly northwest-southeastward trending, fairly symmetrical anticline, although the dip is slightly steeper on the west flank than on the east. Total relief of the structure was not determined by extending the mapping into the synclines, but it is probably in excess of 500 feet. Four prominent domes (three shown on present map) and a few additional very low domes are superposed on the crest of the anticline. The closure on the four larger domes ranges from less than 50 feet to more than 100 feet. Gas has been obtained in wells on the two southernmost of the four prominent domes, and one dry hole has been drilled on each of the other domes. The structure is cut by a small fault along the southwest flank and by two dikes of dense, dark, igneous rock as shown on the map.
HISTORY OF FIELD The discovery gas well was drilled by Foley and Goldsworthy at No. 1 Government on the north line of the NE-NW Sec, 11, T. 30 S., R. 60 W., in 1926 and 1927. It was drilled to a total depth of 2,010 feet. It reached the top of the gas-bearing sand at 900 feet and encountered water 140 feet below the top. The drillers’ log records the Glorieta (Lyons) as being 270 feet thick, below which was red sandy limestone 105 feet thick and red arkose some 725 feet in thickness, It is the writers’ opinion that this well probably bottomed in the upper Madera elastic member of Pennsylvanian age. This section was correlated as the Fountain formation by Bass. The discovery well was abandoned and the Girdler Corporation later drilled the field. Five gas wells and two dry holes were drilled on the anticline in 1929 and 1930. These were located in See. 1, T. 30 S., R. 60 W., and in Secs. 27 and 35, T. 29 S., R. 60 W. The initial daily capacity ranged from 500,000 to 1 million cubic feet of gas per day. The rock pressure was 11 psi (abnormally low). The gas is of particular interest because of its high helium content and complete lack of hydrocarbon gases. The average composition of the gas was: helium, 8 percent; carbon dioxide, 15 percent; nitrogen, 77 percent. The five wells were put on production and from November, 1929, to June, 1930, produced 53,152,000 cubic feet of gas. The Girdler Corporation built a plant at Thatcher, Colo., to process the gas for helium. Later the U. S. Government purchased the entire property of the corporation and reserved the gas for future needs. It has been estimated that 4,380 acres may be productive and that two-thirds of the original gas volume may be recovered by the use of vacuum. The total reserve of helium alone has been calculated as 261,559,000 cubic feet. The nine wells which have been drilled to the Glorieta (Lyons) sandstone have adequately tested that formation. The possibility of deeper production is of course always present inasmuch as onlj7 the upper 830 feet of section below the Glorieta has been penetrated by the drill, It seems logical to the writers that a surface structure of this magnitude might well have deeper reflection and it appears that a deep test is warranted. The field is presently shut in.
I came across this interesting pdf article written in 1956 - The Guidebook to the Geology of the Raton Basin, Colorado - it's in reference to the land around BNL's land - it's a really interesting read (as links sometimes don't work on HC, I've copied and pasted the information below) - cheers MC.
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