USING NOBLE GASES AS NATURAL TRACERS IN THE PANHANDLE-HUGOTON FIELD, TEXAS, UNITED STATES: ASSESSING THE ORIGIN, MIGRATION AND MIXING OF NOBLE GASES AND METHANE

In this study, we present the first complete stable noble gas dataset (He, Ne, Ar, Kr and Xe) for natural gas samples from the Texas Panhandle Field to investigate the composition, sources and migration of both hydrocarbons and helium. This new dataset, combined with that of Ballentine and Lollar [2002] from the Hugoton Field, further north, provides a more comprehensive overview of the entire Panhandle and Hugoton Field (PHF).

A strong positive correlation between terrigenic noble gases (⁴He* and ²¹Ne*) and methane in west Panhandle suggests a common origin for both gases. Both may have originated from adjacent basins to the west, i.e., the Palo Duro and Dalhart basins. In east Panhandle, a positive correlation between terrigenic noble gases and depth points to an upward noble gas flux from underlying rocks. A combined He-Ne analysis reveals the presence of a primordial mantle component in east Panhandle, which likely originated from a mantle plume related to the Wichita Igneous Province. However, an origin from the subcontinental lithospheric mantle (SCLM) cannot be ruled out. Mantle helium is also observed in the west Panhandle Field and has likely originated from the Bravo Dome Field to the west.

Observed ⁴He*/⁴⁰Ar* and ²¹Ne*/⁴⁰Ar* ratios suggest an external origin with an average-lower crustal signature, rather than in-situ production in the reservoir rocks. A first-order estimation of in-situ ⁴He* and ⁴⁰Ar* production suggests that in-situ production across the PHF accounts for a minor portion of the total crustal noble gas content of the field. Contribution from in-situ production is higher in the east Panhandle Field compared to the west. More interaction with groundwater in West Panhandle, Texas and Oklahoma Hugoton gases results in higher water/gas ratios and also higher concentrations of terrigenic noble gases, likely brought by groundwater flow from adjacent areas (i.e., Dalhart and Palo Duro basins). The relatively low water/gas ratios and terrigenic noble gas contents in east Panhandle samples are consistent with the shortest migration distance, youngest migration ages and absence of significant groundwater flow in this area.