Scanning Electron Microscopy and Core Analysis for "Mini" CO2 Flooding Operations in the Hospah Formation of the Miguel Creek Field, McKinley County, New Mexico

Abstract

Abstract A combined laboratory evaluation that included scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction, petrography, and core flow/permeability damage analysis was performed on core samples from the Hospah formation of the Miguel Creek field, McKinley County, NM. The objective of this study was to determine what type of recovery method would be the most beneficial and economical for a pilot five-spot, 8-acre plot. The geologic evaluation of the core samples indicated tremendous lithologie differences in this formation. The rock types contained appreciable amounts of migrating clays (kaolinite and illite). Various degrees of pyrite, total clay content, and residual hydrocarbon saturation also were observed. According to the operator, a conventional waterflood operation attempted during 1974–76 proved unsuccessful. This study indicates that the most likely reason was migratory fines. A foam fracturing technique also was attempted in June 1980 in the Miguel Creek field, with similar negative results. The conclusions from this study suggested that the use of a clay-stabilizing surfactant preflush in a "mini" CO2 waterflood could be an advantageous method of controlling migrating fines and swellable clays.