Play Activity Alert: Horizontal Woodford Shale Oil Play Extended into North Texas

Editor's Note: Periodically, this blog will cover selected milestones in unconventional play development, chosen from IHS Energy Editorial coverage of industry activity. These Play Activity Alerts cover the milestone within the overall context of the play, focusing on technical details of interest to O&G exploration professionals.

A few years ago, a handful of vertical workovers in Texas' Grayson County north of Dallas and bordering Oklahoma were completed as Woodford Shale oil producers by Blackwell BMC, opening the door for future development in Big Mineral Creek field. After assuming operatorship of Blackwell's vertical Woodford wells, Fort Worth-based Jetta Operating recently announced the first horizontal Woodford completion in North Texas.

Jetta's 1H Southland was tested on gas lift for an initial daily potential of 384 bbls of 38-degree oil, 389,000 cu ft of gas and 750 bbls of water. Fracture-treated Woodford perforations are at 9701-12,476 ft. Four-and-a-half-inch liner is set to a total depth of 12,767 ft. The north-trending lateral reached a true vertical depth of 10,154 ft. The company's Marietta-Sherman Basin acreage is near Lake Texoma, over four miles northeast of the town of Sadler.

The 1H Southland will be placed in Big Mineral Creek field, which has primarily produced from various Pennsylvanian pays (Strawn, Barnes and Atoka) in addition to pays in the Ordovician Viola and Oil Creek.

In an application to adopt field rules for the Woodford pool in Big Mineral Creek field, Jetta previously said the Woodford Shale (between the base of the Pennsylvanian Atoka and the top of the Viola lime) is found at depths from 7000-12,000 ft, with a thickness ranging from 50 ft to 400 ft. At that time, Jetta announced its intent to drill horizontal wells and indicated that stacked laterals could be utilized to develop the resources.

Woodford resource play

The Woodford Shale is an unconventional Devonian-age resource play that has been largely contained within the Oklahoma portions of the Anadarko and Arkoma basins and produces oil and gas. A small number of Woodford completions have also been reported in southern Kansas, the Texas Panhandle and the Permian Basin of West Texas.

Horizontal drilling helped the play take off in the mid-2000s with Chesapeake, Cimarex Energy, Continental Resources, Devon Energy, Newfield Exploration, PetroQuest Energy and ExxonMobil subsidiary XTO Energy among the major players over the last decade.

Figure 2 Woodford Permits 2003-2012

Permit activity across the Woodford play during the first half of 2013 is roughly on par with 2012. If the second six months hold course, 2013 levels project to nearly 350 new permits.

Initial Woodford activity in Grayson County

Jetta currently operated the first three vertical Woodford producers in North Texas' Big Mineral Creek field. The lateral of the 1H Southland passes just east of the 3 J.E. Barnes, which was initially completed by Blackwell in December 2009. The workover was tested flowing 63 bbls of 38-degree crude and 887,000 cu ft of gas per day from fracture-stimulated perforations at 7172-7379 ft. The re-entry has produced more than 9,100 bbls of oil and 420 million cu ft of gas.

In 2010 and 2011, Blackwell added two more Woodford workovers to the field. The 44 and 45 Green have combined to produce over 15,000 bbls of crude and 350 million cu ft of gas.

A rate-versus-time graph for Jetta's three Woodford wells in Big Mineral Creek field appears below:

Figure 3 Jetta Woodford wells Rate vs Time Production Graph

Future operations

Jetta has been conducting an extensive horizontal drilling program in Big Mineral Creek field over the last several years, although its primary objective has been the deeper Viola. Immediately east of its 1H Southland, Jetta owns a permit for the 1H Little, which will include a horizontal Viola lateral running parallel to that of the 1H Southland.

Less than three miles to the northeast, Jetta is active at two offsetting horizontal wildcats-one that will target the Woodford and another that will target the Viola. The Viola test has been drilled to a total depth of 17,347 ft (12,503 ft TVD) while operations began at the Woodford test in late June. The Viola test was spud in May.

The nearest horizontal Woodford production is more than 20 miles to the northeast in eastern Marshall County, Oklahoma.

Posted 27 June 2013

This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.