Historic Oil Field
Winkleman Dome is an asymmetrical surface anticline at the northwestern end of the Wind River Basin in Fremont County, Wyoming, lying within the Wind River Indian Reservation. Its distinguishing feature is the crude: shallow, highly saturated, and viscous enough that ordinary pressure-driven recovery leaves most of it in place. That is why the field became a thermal project rather than a conventional one, with Pan American Petroleum beginning forward steam drive operations in the Nugget zone in 1964 and Amoco Production expanding the project later.
Winkleman Dome was identified from the surface, as most Wind River Basin fields were: an asymmetrical anticline with northeast-southwest trending faults, obvious enough to map without instruments. Early production established that the structure held oil, but also that the oil was viscous and the reservoir shallow — a combination that produces disappointing wells under natural drive no matter how many are drilled. The field spent its early decades as a modest producer, which is the usual fate of heavy oil accumulations before thermal recovery became practical.
The turning point came in 1964, when Pan American Petroleum began forward steam drive operations in the Nugget zone. Forward steam drive injects steam to heat the reservoir and lower oil viscosity so the oil will flow toward producing wells. Published evaluations of the project describe expansion under Amoco Production, including five-spot injection patterns placed within the faulted portion of the structure, and note candidly that the Nugget here lacks the thickness, porosity, and permeability found in most successful cyclic steam projects — the process worked despite the rock rather than because of it.
More recent operations at the field have been conducted by Wesco Operating, whose facilities on the reservation are permitted through federal channels rather than state ones — a reminder of the jurisdictional structure that governs everything here. Wells in the field include recompletions and horizontal work under names carrying the Winkleman Dome designation. Owners should note that the roster description of this field as a polymer flood does not match the published record, which describes steam.
Winkleman Dome is an asymmetrical surface anticline at the northwest end of the Wind River Basin, with the accumulation controlled chiefly by structural relief and by northeast-southwest trending faults. The principal producing interval is the Jurassic Nugget, with the Tensleep also present in the section. The reservoir is shallow, holds high oil saturation, and contains viscous crude. Published assessments note that the Nugget here does not have the thickness, porosity, or permeability typical of successful steam projects, which is why the field is studied as an instructive rather than an ideal thermal case.
Thermal recovery defines Winkleman Dome. Forward steam drive — injecting steam continuously so a heat front advances through the reservoir, thinning the oil ahead of it — began in 1964 under Pan American Petroleum and was later expanded by Amoco Production, including five-spot patterns in the faulted part of the structure. Steam is expensive and its economics track fuel costs as much as oil prices, so thermal fields tend to run in cycles of activity and quiescence. That rhythm, rather than reservoir decline alone, is what drives production history here.
The threshold question at Winkleman Dome is not valuation but jurisdiction. The field lies within the Wind River Indian Reservation, where mineral interests are tribal trust or individually allotted acreage administered by the Bureau of Indian Affairs. Those are not conventional fee minerals, they are not conveyed under Wyoming law, and they are not something we purchase. A great deal of Fremont County outside the reservation boundary is ordinary fee mineral title. Where an interest is fee rather than trust or allotted, we buy minerals and royalties in Fremont County and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
The published record describes steam, not polymer. Forward steam drive began in the Nugget zone in 1964 under Pan American Petroleum and was expanded under Amoco Production. Descriptions of the field as a polymer flood appear to be an error.
Not as fee minerals. The field is within the Wind River Indian Reservation, where interests are trust or allotted acreage administered by the Bureau of Indian Affairs under federal law. We do not buy those, and any offer to purchase them should be treated with caution.
It is viscous and the reservoir is shallow, so it will not flow readily to a well under natural pressure. Steam is injected to heat the rock and thin the oil. That works, but it costs fuel, which makes production sensitive to energy prices as well as to oil prices.