Oil & Gas Report

Eagle Ford-Woodbine, mega-giant petroleum fields of Texas

 

 

Let’s begin with significant dates of significant discoveries in the U.S. energy future. First, the date, October 5, 1930 – fastforward eightytwo years later to the same month, different day, October 16, 2008. What an impact those October days had and continue to have in the energy future of our United States of America.

On that historical October

5, 1930 date, energy history was made when the Daisy Bradford No. 3 well was completed for oil at 3,536 feet underneath ground level. There were two previous attempts to tap into that historical East Texas Oil Field, but to no avail, as earlier tries, beginning in 1927, were unsuccessful. Columbus Marion (Dad) Joiner began drilling in 1927 but lost the No. 1 Daisy Bradford because of stuck pipe. The No. 2 Bradford was spud in 1928 and ended in failure when the pipe twisted off. After the Daisy Bradford No. 3 gusher shocked the world in 1930, subsequent wells were drilled and soon a connected oil pool was realized. Within a few months, landowners, investors and drilling companies began to realize they had tapped into a giant oil field less than a mile deep that produced large amounts of oil in a band 40 miles long and four to six miles wide. One of these wells flowed as much as 22,000 barrels of oil per day (BOPD). In fact, the famous East Texas Oil Field provided the U.S. with enough oil to win World War II.

Now let’s consider the historic date of October 16, 2008. That was the date when the STS #1H began producing natural gas and condensate out of the Eagle Ford Shale in the Hawkville (Eagle Ford) Field, eight miles south of Los Angeles, Texas in LaSalle County. Drilled by Petrohawk Energy, it was the first horizontal well drilled into the Eagle Ford Shale and it flowed at a rate of 7.6 million cubic feet of gas per day from a 3,200 foot lateral with ten frac stages. That well marked the beginning of drilling in what has been described as one of the biggest oil and gas discoveries in the last half century. Natural gas, crude oil and condensate are all produced from the Eagle Ford Shale.

I called on Pleasanton geologist Arthur Troell to describe this Eagle Ford trend.

Troell said, “ In Northeast Texas, oil from the Eagle Ford Shale source beds migrated to traps in the Woodbine Sandstone: Such traps include those (1) along faults (Richland Pool), (2) on domes (Van Dome Pool) or (3) in places where Woodbine Sands wedge out (East Texas Pool). The discovery of these pools dates back to the 1920s to 1930s. In all of these occurences, oil flows freely from pores (open spaces) between sand grains. The pores in shales, like the Eagle Ford, are so small, oil will not flow freely from them. Thus the Eagle Ford must be fractured (fracked) to produce because most of the oil and gas still remains in the source beds due to the lack of permeability.”

Troell continued, “Historically, it is extremely rare to find natural oil production from a shale formation. One exception to this was the Florence Oil Field in Colorado, discovered in 1876, which produced oil from natural fractures in the Pierre Shale of Upper Cretaceous Age.”

Continuing, “In South Texas, the Woodbine Sand was not deposited, (does not occur), south of Waco. Historically, there were few if any oil wells completed from the Eagle Ford although the Eagle Ford was known to be the source beds for oil trapped in the Woodbine Sands in East Texas. It is important to note that the Eagle Ford is a true shale in North Texas whereas it contains up to seventy percent calcium carbonate (lime mud) in South Texas.” “Successful hydraulic fracturing (fracking) of shales such as the Barnett Shale (Mississippian) in North Texas and the Haynesville Shale (Jurassic) of North Louisiana led Petrohawk Energy to lease acreage in La Salle County beginning in 2007. The discovery well, the STS #1H was completed on October 16, 2008.” Said Troell, adding, “The activity continues. The production is a huge field of wells, not individual pools. Production occurs in bands: (1) shallower oil, (2) intermediate dip condensate and (3) deeper down-dip gas.”

Troell added, “No one knows how much petroleum the Eagle Ford Shale may ultimately yield but it could rival or even exceed the six billion plus barrels of oil or BOE ( barrels of oil equivalent) produced from the East Texas Pool of historic fame.” Continuing, Troell said, “Hopefully, Eagle Ford production will have the longevity of the East Texas Pool in the Kilgore-Gladewater area which still produces oil today, eighty-two years after Dad Joiner and Daisy Bradford made ‘black gold’ history.”


SOUTH TEXAS – NORTHEAST TEXAS:

SOUTH TEXAS – NORTHEAST TEXAS:

Geologic columns showing presence of Woodbine Sand beneath the Eagle Ford Shale in Northeast Texas and the absence of Woodbine Sand in South Texas due to nondeposition.

Geologic columns showing presence of Woodbine Sand beneath the Eagle Ford Shale in Northeast Texas and the absence of Woodbine Sand in South Texas due to nondeposition.

 

 

ARTHUR TROELL GEOLOGIST

ARTHUR TROELL GEOLOGIST

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