Helix Exploration PLC
INGOMAR DOME
The Ingomar Dome in South-Central Montana represents the largest, single structure multi-Bcf, geological hydrogen and pure-helium (helium as a primary target) play in the United States.
Helix Exploration PLC (operating in Montana as Hereford Resources, LLC) drilled a well last month (August 2024) on the apex of the anticline and received exceptional results from the mudlog demonstrating high helium concentrations in the two "upper" zones and up to 10.5 % Hydrogen on the mass spectrometer over the deeper Flathead sandstone. Concentrations of this magnitude highlight the probable greater in-situ concentrations of hydrogen in the formation. This 10% Hydrogen show over a thick interval proves the presence of a hydrogen system that could be capable of production quickly.
Upon the "wash" trip to clean the hole prior to wireline logging, the shallow Mowry shale became unstable so we made the decision to pull in a larger rig to help set 7" casing over the Mowry formation and continue to clean out the wellbore below. The new rig could be on location as early as three weeks (late September 2024).
The Ingomar Dome has a rich history of oil exploration because it was a well known surface anticline, which was the primary method of exploration in the early days of wildcatting. Although no oil or methane was discovered, several zones tested "non-burnable" gas, but were never analyzed for helium or hydrogen. In this area of Montana, any nitrogen-rich gas zone is always associated with helium. Thus, we anticipate a rich component of helium (~1.5 %) given comparables in the area (see the Comparables tab).
In addition to the known inert gas-bearing horizons, the deeper Cambrian Flathead formation represents a potential world-class hydrogen and helium resource which was just penetrated on our Clink #1 well on the apex of the structure. The Flathead is a clean, porous and permeable sandstone which demonstrated our 10.5% hydrogen result on the mudlog. A well six miles to the west (and off-structure) of the Dome penetrated the Flathead and logs highlight clean Gamma Ray with Cross-Over Porosity (gas-bearing). The Central Montana area remained a deep, 14,000 - 16,000 ft trough that accumulated classics from Cambrian through lower Devonian periods until the trough became "inverted" via uplift during Devonian time. Thus, the Flathead formation is "intact" on the dome.
The tabs above give a solid and full geological picture of the Dome and its potential.
History of the Ingomar Dome
Exploration on the Ingomar Dome began in 1920 when Absaroka Oil Company drilled the Savage #1 well, TD’ing at 3,040’ in the Kootenai (Jurassic) formation (dry hole). At that time, the Ingomar Dome was a known surface anticline thus the reason for Absaroka’s exploration activities in the area as virtually all exploration in any part of the United States was done on or near surface anticlines prior to the advent of seismic. Absaroka would drill one more well on the Dome TD’ing at only 50 feet.
In 1926, the United States Geological Survey published a paper titled, The Geology of the Ingomar Anticline Treasure and Rosebud Counties Montana by K.C. Heald. In it, Heald outlined possible future exploration targets using Absaroka’s only well as a go by. Even this study, however, did not spur exploration on the Dome for another 17 years until Northern Ordinance drilled two deep holes in 1943 and 1944.
Near the apex of the surface anticline, the Northern Ordinance Hillison #1 well discovered “non-burnable” gas flowing 8.2 MMcfpd out of the Late Mississippian-Early Pennsylvanian-aged Amsden formation (the Amsden, found at 3,900' on the Ingomar Dome is the productive, oil-bearing zone in the nearby Gage, Big Wall, Sumatra, and Wolf Springs Fields). Nearly concurrently on a well drilled one mile to the southwest, the Northern Ordinance NPRR #1 well mentions “nitrogen” flows out of the Amsden as well (the NPRR #1 well was structurally lower on the Amsden).
Four samples of gas were collected on the Hillison #1 well and sent to various laboratories. The USGS found this gas to contain 82.63% Nitrogen, 12.75% Methane, 4.03% Ethane, 0.39% Oxygen, and 0.2% Carbon Dioxide. No attribution or line item was made for helium meaning that it was not analyzed. Two other private laboratories would yield very similar results but a helium analysis was not performed as private labs lacked the ability to analyze helium in 1944.
The last sample was sent to the United States Bureau of Mines which did have the ability to analyze for helium but the sample results were skewed from the original three. The Nitrogen composition dropped by 4%, the Oxygen by 100%, and the Methane by 1.2%. The Ethane component, however, increased by 98%. Thus, IF the USBM analyzed for helium, an evident leak in the bottle caused the lighter elements to escape allowing for the heavier ethane molecules to become enriched. It should also be noted that this sample remained in a bottle for over a month prior to its analysis. Northern Ordinance left the area after these wells stating in the well file, “there is no further use of this gas.”
Twelve years would elapse before another operator would drill another well on the Ingomar Dome. Between 1956 and 1975 only nine wells were drilled on the Dome (a density of one well
per 3.5 sections). Nearly all of them were drilled on the Rosebud County (structurally higher) part of the Ingomar Dome. The deepest of these wells only penetrated the Kibbey Lime (Mississippian) at 4,974’. Of these wells, only one well, the American Metal NPRR #1 located on the far western edge of the Dome Drill Stem Tested the Amsden formation (rec. 60’ mud, 2,040’ saline water). During this period only one operator tested the Piper formation but all others performed no Drill Stem Tests. All wells during this period were dry.
In 1985, Texas Gas Exploration Company drilled a deep test (upper Cambrian) on the south end of the Ingomar Dome which found “non-burnable” gas in the Charles (Mississippian) formation. Although the results were poor, this well further demonstrated the presence of inert gas in deeper intervals on the Dome. The last well on the Dome was a shallow Cretacious test to 2,187 feet in 2001.
Although the Amsden formation potential is enormous along with several up-dip porosity zones demonstrated in the Raw Log Section of this website, the most exciting and possibly the most productive interval is the lower Cambrian Flathead Sandstone that directly overlies the Precambrian. A well drilled by Southport Exploration 6.5 miles to the west (and well off structure) found crossover porosity in the Flathead. Further, this well found nitrogen gas (i.e. helium-bearing) in the Charles formation. As the Flathead is present in this part of Central Montana, this zone represents one of the most lucrative targets in all of Montana.
The Ingomar Dome represents the largest domestic helium project available today. Two zones have demonstrated inert gases with flows and the Flathead Formation has never been tested. No other helium projects that exist today have potential multiple pay zones, especially in an area of extreme tectonic activity (which is crucial for helium to occur).
Surface Setting
Below is a map from: Characteristics of the Judith River Aquifer in Treasure and Yellowstone Counties. The top map further demonstrates the Cretaceous structure of Ingomar Dome, and exemplified below in the stratigraphic cross section (C to C').
