WESTERN OVERTHRUST BELT PETROLEUM PROVINCE
REGIONAL SOIL GAS GEOCHEMICAL SURVEY
A very large regional geochemical survey consisting of 5728 four-foot soil gas sites is available for sale in the Western Overthrust Belt of western Wyoming and eastern Utah and Idaho. The regional soil gas survey covers an area of about 5900 square miles (Figure 1).
Three criteria were used in designing the locations of the soil gas sampling sites: (1) collect one sample per section (640 ac.) to attempt to establish a uniform sampling density, (2) sample locations were purposely selected adjacent to long and straight stream systems and surface traces of major thrust faults based on the assumption these lineaments would be related to fracturing, and (3) samples were located near roads, trails or other easy access after the first two criteria were met.
The regional soil gas survey was also designed so that it included the Whitney Canyon-Carter Creek and Ryckman Creek-Clear Creek regional productive fairways for the purpose of calibration with established production. There are two productive trends within the survey area (Figure 1): (1) eastern trend containing the Ryckman Creek-Clear Creek Fields (condensate and gas), and (2) western trend containing the Whitney Canyon-Carter Creek Fields (gas with some condensate).
The distribution of magnitude data from this survey clearly identifies numerous, non-random, clusters of anomalously high surface occurrences of light hydrocarbons that are on trend with productive fields to the south. The composition (ratios of ethane to propane) of the anomalous microseep clusters are very similar to those of the hydrocarbons produced from the fields referenced above. The resultant distributions of the observed light gas microseepage documents that the soil gases have migrated to the surface both laterally along thrust-fault planes and vertically from the entrapped hydrocarbons below.
The primary value of this regional geochemical survey is that of focusing on, or emphasizing, the identification of broad areas of interest (for further delineation) in the vast overthrust petroleum province, rather than direct identification of individual drilling locations. Further infill soil gas surveys could be conducted later in the areas of the regional anomalies exhibited in this survey to define exploration prospect areas.
This regional soil gas geochemical database is available for sale, in whole or in part, for the considerations listed below. The minimum data block that should be considered for purchase is 10 townships. To enhance the geochemical interpretation, it is required that the data blocks selected for purchase all have contiguous boundaries.
Price Schedule for Data Purchase
Deliverables include a soil gas sample location map, database of x and y coordinates for the soil gas sample locations, and analyses tables of light hydrocarbon magnitudes (methane to butanes) by FID analyses and He, and H2, by TCD analyses.
An extensive discussion and interpretation of the data from southern
portion this survey has been published by Dickinson
and Matthews – “Regional Microseep Survey of Part of the Productive
Wyoming-Utah Thrust Belt” (AAPG Bull., 1993, p. 1710-1722) - PDF
format, 1.1 MB