U.S. OPERATORS EXPAND HORIZONTAL PROGRAMS

G. Alan Petzet
Exploration Editor

Operators are fanning out across the U.S. with horizontal drilling programs completions in many fields and reservoirs.

Most oil and gas producing states now have multiple horizontal wells, although the South Texas Cretaceous Austin chalk play is not likely to be matched soon by any other horizontal play in number of wells and production.

Figures show 847 horizontal drilling permits were issued in the U.S. during January-September 1990, up from 257 in all of 1989. Horizontal well permits numbered 97 in September, down from 119 in August and 123, the highest monthly total, in May 1990.

Nearly all operators decline to provide production information. But in some areas that's available with some lag time from state agencies.

Here is a rundown of selected areas, by state, of action in the South:

ALABAMA

ARCO Oil & Gas Co. is preparing to drill a Cambro-Ordovician Knox test in Hale County, Ala.

Its 1 Cypress B-4 Unit, 33-23n-4e, is expected to have a true vertical depth (TVD) of 4,142 ft.

Meanwhile, Smackco Ltd., Brewton, Ala., reports good production at its 1 Cruit 26-15, a horizontal extension of a former vertical Jurassic Smackover oil producer in Huxford field, Escambia County.

The well reached horizontal at 14,936 ft, surpassing the previous world record of 11,484 ft, then continued to build and hold angle of about 100 for a length of 405 ft in Smackover (see map, OGJ, May 21, p. 23).

The horizontal leg cost about half the price of a new vertical hole from surface and has been an economic success, the operator said.

Production averaged 215 b/d of oil for 114 days. The operator had to shut the well in after lightning struck a gas processing plant serving the field Aug. 30.

The field's vertical wells have been returned to production, but nitrogen jetting with coiled tubing will be required at the horizontal well.

LOUISIANA

Woolf & Magee Inc., Tyler, Tex., and JWR Exploration Inc., Houston, were attempting a horizontal hole to Cretaceous Saratoga chalk at 5,900 ft in Fort Jessup field, Sabine Parish, of Northwest Louisiana.

Swelling of Eocene Midway shale at about 3,060 ft was hampering insertion of an angle building assembly at Wolf & Magee 1 Sonat Mineral C-15.

The two partners had an early success at 1-A Sonat Mineral B-5, in Pendleton-Many field in Sabine Parish, about 8 miles northwest of the presently active well.

The 1-A well was completed May 17 flowing 104 b/d of 41.4 gravity oil and 15 Mcfd of gas, no water, from Saratoga at about 2,320 ft TVD, Petroleum Information reported.

That well began producing water early in July and as of mid-July was producing about 30 b/d of oil and 130 b/d of water. W&M and JWR allowed a permit to drill an offset well to expire.

OXY USA Inc., Houston, spudded 13-1 Tremont H early this month in Olla field, LaSalle Parish, Northeast Louisiana. OXY intends a 1,000 ft horizontal hole to penetrate Eocene Wilcox.

The company completed a vertical Wilcox well in the field in July for 15 b/d of oil, 42 Mcfd of gas, and 157 b/d of water on the pump from perforations at 2,794-2,804 ft.

MISSISSIPPI

Amoco Production Co. earlier this year completed Mississippi's first two horizontal wells, in Clear Springs field, Franklin County.

The goal was to reduce water coning in Eocene Wilcox at about 4,700 ft, wrote Jack Moody of the Mississippi Bureau of Geology.

Initial potential at the 17 USA well was 320 b/d of oil, 103 Mcfd of gas, and 21 b/d of water through an 18/64 in. choke. IP at the 18 USA was 472 b/d of oil and 43.5 Mcfd of gas through a 15/64 in. choke.

After 6 weeks of production, each well was being produced at a rate of about 300 b/d of fluid. Oil cuts were 70-75% at the 17 USA well and 45% at the 18 USA well.

As of July the 17 USA was flowing 140 b/d of oil and 120 b/d of water through a 12/64 in. choke with 220 psi flowing tubing pressure.

"The No. 17 well is a tremendous improvement over vertical wells in the field," Moody wrote.

Amoco last month staked three more horizontal attempts in the field, about 1/2 mile northwest of the two on production.

OTHER TEXAS

Many operators are drilling horizontally outside the main Austin chalk play in other areas of Texas.

In South Texas, C. Hodge Energy Inc., Garland, Tex., in mid-August staked 25 Liebe-House, in Fairfield field, Bexar County, as a 1,500 ft horizontal drainhole in Upper Cretaceous Anacacho at TVD 1,400 ft.

Dorris Petroleum Co., San Antonio, in August was testing a horizontal well projected to Anacacho in Somerset field, Bexar County. The company planned 1 H Barnes, a horizontal Austin chalk well in the same area.

Waters Operating Co., Corpus Christi, in early October staked 1 Yanta, the first horizontal well in Medina County, Tex., in Ina-Taylor field. Austin chalk is the objective in a lateral to be drilled about 1,854 ft south of the surface location.

Maxus Energy Corp. told shareholders earlier this year it planned to try horizontal drilling in Bigfoot Cretaceous Olmos sand field, near Devine in Medina County, Tex.

In East Texas, Maersk Energy, Houston, in early September staked 1 Arco, in Sabine County. Objective is Austin chalk at TVD 8,425 ft.

Proposed bottomhole location of the well is in Newton County, 1/2 mile south of Brookland field, which has produced 121,041 bbl of oil and 368.2 MMcf of gas from three vertical Austin chalk wells since discovery in 1983.

Maxwell Oil & Gas Co., Kilgore, staked 1 Paul in Center field, Shelby County. It is to bottom 940 ft north of the surface location in Saratoga chalk.

In North Texas, Weber Energy Corp., Dallas, in August planned two horizontal wildcats to TVD 9,000 ft in Hardeman County.

The 1 Johnson is 3/8 mile northwest of Grosebeck Creek field, and the 2 Pease River is 2 miles east of Kadane Cata field.

In the Panhandle, Future Petroleum Corp., Dallas, planned to drill 1,500-1,700 ft of horizontal section in Permian Brown dolomite at TVD 2,600 ft at 9 LeFors, in East Panhandle field.

The well was expected to intersect an existing vertical wellbore.

WEST PANHANDLE-CARSON

Service Fracturing Co., a Pampa, Tex., pumping services company, had limited success at a project in West Panhandle-Carson field to connect a new high angle well with an existing vertical oil well (OGJ, June 25, p. 22). The company plans to try again.

The Carson County project was successful mechanically, but a frac job penetrated into bottom water in Permian Brown dolomite, said Jerry Guinn, Service Fracturing president.

The idea was to use the existing No. 14 well's vertical rod and beam pump system to drain oil from 871 ft of open hole inclined at about 80 in Brown dolomite in the 14S high angle well.

Brown in an adjacent vertical well has permeability of 200 md to more than 2 darcies, average porosity of more than 20%, and reservoir pressure is less than 5 psi.

Cores in the 14S confirmed those parameters and showed the natural fractures to be 5 off vertical and oriented E. 10 N.

Guinn said the 14S is the first horizontal well permitted in Texas to deliberately intersect a vertical well, first drainhole permitted in Texas to produce from a second well at the bottom of the drainhole, and first drainhole permitted for completion in Panhandle field Brown dolomite.

It is also, to his knowledge, the first drainhole to be fracture treated from each end and, to minimize screenouts, both ends at the same time.

The frac job took place July 27 and propagated many vertical fractures along 600 ft of the inclined wellbore.

Pump tests continue at the rate of 300 b/d of fluid. Oil rate has declined from 30 b/d just after the frac.