Historic Oil Field
Eagleville is the Railroad Commission’s designation for the heart of the Eagle Ford oil window, a consolidated field that sprawls across Karnes, DeWitt, Gonzales, La Salle and roughly a dozen other South Texas counties. It is not a conventional field in the old sense — there is no single trap or reservoir — but it is enormous. The US Energy Information Administration ranked Eagleville the number one oil field in the United States by proved reserves as of December 31, 2013, the year it produced about 238 million barrels of oil and lease condensate. For mineral owners, it remains the most valuable royalty address in South Texas.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 27135700, 27135750. Reported volumes lag the calendar by several months.
The Eagle Ford story starts in 2008, when Petrohawk Energy completed the play’s first commercial horizontal well in La Salle County. That discovery opened a gas and condensate play, but within a year operators had traced the shale updip to the northeast, into the shallower, oil-rich part of the trend beneath Karnes, DeWitt and Gonzales counties. The Railroad Commission created the Eagleville (Eagle Ford) designations in 2009 to administer that development, and the name quickly became shorthand for the best rock in the play.
Development moved fast. By the early 2010s the Karnes-DeWitt corridor was drawing many of the highest initial-rate oil wells in the country, and Eagle Ford production for the play as a whole peaked in March 2015 at roughly 1.6 million barrels of oil per day. The 2015-2016 price collapse and the 2020 demand shock both cut drilling sharply, but each recovery brought longer laterals, larger fracs and tighter well spacing rather than a return to the original development pattern.
The modern Eagleville is a consolidation story. Acreage that was assembled by dozens of independents in the leasing rush has been traded into fewer, larger hands, and much of the drilling is now infill and refrac work inside units that were established a decade or more ago. Because operatorship in the play changes hands regularly, an owner’s check detail is often the most reliable place to see who is actually running the wells under a given tract today.
The Eagle Ford is an organic-rich Upper Cretaceous marine shale and marl deposited across what is now a roughly 50-mile-wide band of South Texas. It deepens and thickens toward the southeast, and that depth gradient controls everything: shallow, less mature rock in the northwest produces black oil, the mid-trend produces volatile oil and condensate, and the deep southeast produces dry gas. Eagleville sits squarely on the oil and volatile-oil side of that gradient at depths of roughly 8,000 to 12,000 feet. The rock has almost no natural permeability, so every well is horizontal and multi-stage fracture stimulated.
There is no waterflood or CO2 flood at Eagleville, and there probably never will be — the shale is far too tight for conventional secondary recovery to sweep it. What passes for enhanced recovery here is engineering: longer laterals, higher proppant loading, tighter cluster spacing, gas lift as reservoir pressure falls, and refracturing older wells that were completed with early-generation designs. Some operators have tested cyclic gas injection, or huff-and-puff, in Eagle Ford wells with mixed published results. Each of these adds barrels, but none of them flattens the decline curve the way a waterflood does in a conventional field.
Eagleville royalties behave nothing like the old Permian and Gulf Coast waterfloods. A horizontal Eagle Ford well typically pays a large share of its lifetime revenue in its first two or three years, then settles onto a long, thin tail. That front-loading means the timing of a sale matters enormously: an interest under new wells is worth far more than the same decimal under ten-year-old wells, and buyers price undrilled acreage very differently from producing units. We buy minerals and royalties in Karnes, DeWitt, Gonzales and La Salle counties and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
Eagleville is the Railroad Commission field name assigned to much of the Eagle Ford oil window. Eagle Ford is the geologic formation. Operators report production to the state under the field designation, so your division order and check detail will often show Eagleville even though the rock being produced is the Eagle Ford Shale.
Steeply at first. Eagle Ford horizontals commonly lose a large fraction of their initial rate within the first year and continue declining sharply through year three before flattening into a low, long tail. Owners who bought or inherited an interest during the first flush of production are often surprised by how much the monthly check falls by year four.
Often yes. Undrilled locations inside the core counties still carry real value because the rock is proven and the infrastructure is built. Value depends on how many additional wells a buyer believes will be drilled on your tract, the spacing plan, and whether your acreage is already pooled into producing units. We will explain how we underwrite the undeveloped portion of your interest.