USING NON-SEISMIC METHODS TO ANALYZE SALT STRUCTURE OF THE ONION CREEK SALT DIAPIR, UTAH

The Onion Creek salt diapir lies within the Paradox Basin in Utah and Colorado where it is part of a series of salt walls that separate the Paradox Basin into smaller sub-basins. These sub-basins and associated salt diapirs remain key to several oil and gas traps in the region. At the surface, a postulated salt shoulder associated with the Onion Creek diapir is potentially concealed by the overburden of the Permian Cutler Formation. I have used gravity and magnetics methods to better determine the extent and shape of the salt shoulder near the Onion Creek salt diapir. Since the salt is less dense than the Cutler Formation, gravity methods are the best at defining the salt shoulder extent while magnetic methods help to delineate the more highly magnetic Cutler Formation. My initial results from gravity data collected in April 2019 show a low over the diapir and then a gradual increase in gravity readings that I interpret to represent more of the Cutler Formation covering the salt shoulder. Initial magnetics data along two lines, also collected in April 2019, display a similar trend with a low over the diapir with values that generally increase with more Cutler sediment cover. A full magnetics survey was run in July to create a magnetics map of the area of interest, this data is key to showing the structural relationship between the salt and sediments of the Cutler. Lastly, a few more gravity points were collected to tie with some abandoned petroleum exploration wells in the area for a control on depth.