Oil production from Cretaceous Austin chalk horizontal wells in a South Texas field is 100 times greater than it was 1 1/2 years ago, officials of Oryx Energy Co., Dallas, have told the Texas Railroad Commission (TRC).
Oryx said this increased production supports its position that temporary field rules on horizontal drilling in Pearsall field should be made permanent.
TRC conducted hearings last week on the temporary rule providing a four-fold increase in horizontal well allowables, to 1,312 b/d from 328 b/d, based on 2,431 ft displacement and 320 acre spacing.
It applied similar reasoning in April for a statewide horizontal well rule.
Since January 1989, Oryx said, its Pearsall field oil production has surged to more than 16,000 b/d from 160 b/d. Displacement has increased to more than 3,000 ft/well from less than 1,000 ft, and mean cost has been reduced to $1.2 million/well from $2.7 million. Some wells have more than 4,000 ft displacement.
Oryx completed 21 Austin chalk wells in first quarter 1990.
WELL COMPARISON
Oryx compared production histories of seven horizontal wells with some typical vertical wells, all completed in Austin chalk.
The horizontal wells produce a total of about 3,000 b/d and have produced nearly 800,000 bbl in the past 1-3 years. Their proved reserves are about 450,000 bbl/well.
In one example, Oryx told TRC its 13 J.B. Baggett horizontal well has produced 206,000 bbl since May 1988. On the same lease, its 7 J.B. Baggett, one of the better vertical wells in Pearsall field, has produced a total of 126,359 bbl during 9 years.
In June, there were 92 rigs drilling Austin chalk wells in TRC Dist. 1-which includes Pearsall field-nearly eight times as many as the 12 rigs operating there in November 1989 when TRC issued the temporary field rules.
Oryx plans to use horizontal technology in drilling Ordovician Ellenburger in Nolan County, Tex., Mississippian Bakken shale in North Dakota, and Cretaceous Niobrara in Colorado.
It has also used a horizontal well for steam injection in California's Midway-Sunset field.
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