S. Korea's Yukong Sets U.S. E&D Joint Venture

G. Alan Petzet
Exploration Editor

Yukong Ltd., Seoul, has activated its first U.S. upstream joint venture with the purchase of working interests in five Texas and Louisiana onshore fields.

SK E&P, Yukong's U.S. unit, paid $24 million for 49% working interests in Kohler, Trinity, and Maurbro fields in Texas and 60% interests in Port Barre and Iberia fields in Louisiana. Overall output is 3,200 b/d of oil equivalent, and reserves are estimated at a combined 10.6 million BOE proved and 15.6 million probable.

The seller, which operates the five fields, is Manti Resources Inc., a private Corpus Christi company formed in 1989 largely by ex-Exxon Corpus Christi engineers.

3D seismic surveys are in progress or planned in all fields except Maurbro. Manti and SK plan exploration and exploitation activities mainly at Trinity, Port Barre, and Iberia fields, where multiple stacked pay zones are unexplored on piercement salt dome flanks.

Manti and Yukong will collaborate on future domestic and international exploration and acquisition opportunities.

Yukong's SK E&P, which opened a Houston office, is not related to SK Resources, Houston, which is active in the East Texas Cotton Valley reef gas play.

Manti acquired the Texas fields from Exxon in February 1996 and the Louisiana fields from M&R Exploration, Houston, in June 1997. It also purchased key Trinity field flank acreage.

Manti, which operates properties in South, West, and East Texas and Lou- isiana, hopes to pursue other U.S. opportunities joinly with Yukong, said Lee Barberito, Manti president. Manti also plans to start operating in Australia, New Zealand, Venezuela, and Colombia by yearend.

Dr. K. Son is representative of SK E&P in Houston. Yukong has 20 exploration initiatives in 10 countries including Ecuador, Libya, and Australia.

Here is a look at exploration and exploitation action Manti and SK plan for the fields, which will involve capital spending in addition to the sum SK paid for its working interests.

Kohler field

The main focus in Kohler field, Duval County, Tex., is to define and drill untested traps in Eocene Wilcox.

Two wells have reached Wilcox Hinnant at 9,000-14,000 ft. The field, covering 11,000 acres, has produced 55 bcf of gas and 6.4 million bbl of oil since discovery in 1926, mostly from Queen City sands on 5,000 acres. Other production comes from Oak- ville, Cole, Hockley, Mirando, and Yegua, which represent 26 pays at 600-4,500 ft.

A field study is under way to identify infill and extension opportunities in historically productive zones through Queen City.

A range of structural and stratigraphic trapping mechanisms and significant unexplored acreage warrant the investment in 3D seismic, said Gary Mize, Manti executive vice-president. A 25 sq mile 3D survey to be finished by yearend has been optimized to image targets at Queen City level and should generate numerous shallow low cost targets.

Manti has boosted Kohler's gas sales fourfold since buying the field in February 1996 by modifying facilities and increasing gas lift gas to oil wells.

Maurbro field

Manti has hiked production to 320 b/d from 230 b/d in Maubro field, Jackson County, Tex., which has produced 22 million bbl since discovery in 1941.

Drilling this year is to test a prime infill location that should aid in the decision to increase well densities fieldwide. Other wells are plan-ned to Frio objectives at 5,500 ft and 7,500 ft and other shallow gas anomalies.

Before acquisition Manti's studies indicated it could add reserves with increased Marg well densities and possibly a pattern waterflood, exploring the Frio which produces in other fields on trend with Maurbro, and exploiting log-confirmed potential for shallow gas, 30 bcf of which has been produced only on the field's east flank.

Trinity field

Since discovery in 1934 this Houston County, Tex., field has produced mainly from Wilcox/Carrizo at 2,500 ft atop a salt dome. Shallower undeveloped pays exist in Crockett, Queen City, and Sparta sands. Also limited Edwards and Woodbine production on the flanks of the dome.

Since the initial acquisition in February 1996 of acreage controlling the top of the dome, Manti has acquired an further 3,700 acres on the flanks.

Manti was also successful in reclassifying Trinity as a salt dome field after technical presentations to the Texas Railroad Commission. The new salt dome classification, along with the control of top and flank acreage positions, provides for the first time in the field's history an opportunity for fieldwide management based on a planned 3D survey.

Based on the established Woodbine and Edwards flank production, Manti anticipates that the 3D survey will identify piercement traps along the face of the dome in multiple regional pays from Cotton Valley up through Woodbine. And 2D seismic indicates additional Wilcox potential in a rim anticline feature.

Iberia field

Iberia is producing 1,400 b/d of oil and 3.3 MMcfd of gas from Middle to Lower Miocene age sands at 800-10,500 ft.

The field, in Iberia Parish, La., has produced more than 100 million bbl of oil and 100 bcf of gas since discovery in February 1917.

About 25 of 75 existing standing well bores were active when Manti assumed operations.

It plans to reactivate many of the idle wells.

State of the art 3D seismic will be used to support redevelopment and delineate deeper potential.

Most of Iberia's reservoirs produce oil. With modern completion techniques even an old field can give up high rates such as at the 1 Bullock, which flowed 650 b/d of oil on a 12/64 in. choke.

Some of the deeper reservoirs produce gas, including the Germany sand.

Manti joined Sonat Exploration Inc. in acquiring a 36.5 sq mile 3D seismic survey over the Iberia salt dome. Processed data are expected in September.

Port Barre field

This field in St. Landry Parish, La., is producing 280 b/d of oil from Pliocene through Frio age sands in 19 wells.

Port Barre has exceeded 50 million bbl of oil and 75 bcf of gas since July 1927. Manti plans to reactivate many of 49 shut-in wells following a geologic and engineering study.

Manti and HS Resources expect processed data in fourth quarter 1997 from a 50 sq mile 3D survey over the complexly faulted salt dome. The data tied to well control will define untested fault blocks and delineate deep reservoirs.

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