Wertz Field sits at Bairoil in south-central Wyoming, immediately alongside Lost Soldier, and the two have been run for decades as a single integrated CO2 project. Sinclair Oil and Gas discovered Wertz in 1936, and the Pennsylvanian Tensleep sandstone has been its principal reservoir ever since. What distinguishes Wertz is chronology: carbon dioxide injection began here in late October 1986, making it one of the first fields in the Rocky Mountain region to undergo field-scale miscible CO2 flooding rather than merely to be studied for it.
Sinclair Oil and Gas found Wertz in 1936, during the campaign that mapped the string of anticlines running through the Lost Soldier and Ferris district. Early production came from a combination of fluid expansion and water influx — a natural drive that would deplete on its own schedule regardless of how many wells were drilled. Operators recognized that early, and gas injection was started in 1941, an unusually forward-looking pressure-maintenance decision for a field only five years old and one that shaped everything that followed.
Amoco acquired the Bairoil properties in December 1975 and set about engineering the next stage. Miscible carbon dioxide flooding of the Tensleep was designed through the following decade and injection began in late October 1986, supplied through the pipeline infrastructure that also serves neighbouring Lost Soldier from the CO2 source in western Wyoming. Technical papers on the Wertz Tensleep CO2 flood document the engineering design and early performance in detail, and the project is treated in the literature as a reference case for miscible flooding in Rocky Mountain sandstone.
Operating a flood for four decades is largely a matter of controlling where the injected fluid goes. Case histories from Wertz describe gel conformance treatments at injection wells, placed to block the high-permeability streaks that would otherwise let CO2 short-circuit past the oil it is meant to sweep. The field has been run in recent years as part of the Bairoil complex alongside Lost Soldier, and owners should confirm current operatorship from a division order rather than from published history.
Wertz produces from the Pennsylvanian Tensleep sandstone, an eolian unit whose cross-bedded architecture gives it good porosity and highly variable permeability. The field lies on an anticline in the Bairoil area at the eastern edge of the Greater Green River Basin, adjacent to and structurally similar to Lost Soldier. Tensleep permeability contrast is the defining engineering problem in these fields: injected fluid finds the best-connected laminae and races ahead, leaving oil in the tighter units behind. Almost everything done at Wertz since 1986 has been aimed at that single characteristic.
Wertz is one of the earliest field-scale miscible CO2 floods in the Rockies. Miscible carbon dioxide mixes with residual oil rather than merely displacing it, swelling the oil and reducing its viscosity so it can move through rock a waterflood has already swept. Injection began in late October 1986 and has continued since, with gel conformance treatments used at injectors to force CO2 into rock it would otherwise bypass. For owners, the meaningful point is that production here is a function of continuing CO2 purchases and injection, not of new drilling.
Wertz interests behave like Lost Soldier interests: long-dated, flood-supported, and dependent on an operator’s ongoing commitment to buying and injecting CO2. That is a genuinely different valuation problem from a declining conventional well, because the tail can extend for decades or contract quickly if injection stops. The Bairoil area also spans the Sweetwater and Carbon County line, so title work can involve both counties. We buy minerals and royalties in Sweetwater and Carbon Counties and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
They are adjacent fields at Bairoil that have been operated together as an integrated CO2 project. Both produce from the Tensleep and both were brought under miscible carbon dioxide flooding in the 1980s using the same pipeline infrastructure.
Injection began in late October 1986, following a design effort under Amoco, which had acquired the Bairoil properties in December 1975. Gas injection for pressure maintenance had already been running at the field since 1941.
Production would decline much faster than it does under injection, because the flood is what keeps oil moving. That risk is exactly why interests like this should be valued by modeling the flood rather than by applying a multiple to recent income.