Crooks Gap Field

Fig. 2. Thin-section photomicrograph of Dakota sandstone from Crooks Gap field, 1539 m (5048 ft), showing small, dispersed nature of the calcite (arrow). Scale bar = 144 nm.

Smith, L.K., MacGowan, D.B. Surdam, R.C. (1991) Scale prediction during COj hufTn puff enhanced recovery, Crooks Gap field, Wyoming. Proceedings of the SPE Rocky Mountain Regional Meeting, Denver. April 1991, SPE Paper 21838. 

Table 1. Pre- and post-C02 treatment water analyses for Crooks Gap and Bonanza Fields...

In addition to increased calcium and magnesium in the post-C02 water, bicarbonate also increased at Crooks Gap and Bonanza where this analysis was performed (Fig. 5 Table 1). At Bonanza field, bicarbonate increased from an average of 446 ppm... 

The increases in silica and aluminium are indications of aluminosilicate alteration and/or dissolution, although the data are insufficient to determine specific mechanisms. Several mechanisms involving more than one aluminosilicate mineral may be operating, and they may be different in the two fields. At Crooks Gap, the aluminium probably comes from sodic plagioclase which is the most... 

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