Area Drilling

Dec. 24, 2007


Argenta Oil & Gas Inc., Toronto, said logs identified at least three potential pay zones per well in its first two exploratory wells on its 100% owned Loma El Divisadero property in Argentina’s Neuquen basin.

Argenta set production pipe at the Ledo-x2 and ADC-x1 wells, drilled to 1,615 m and 1,496 m, respectively.

Colombia - Putumayo basin

Gran Tierra Energy Inc., Calgary, spud the first of two delineation wells at Costayaco field on the Chaza Block in the Putumayo basin.

The field discovery well, which tested at as much as 5,906 b/d of oil from four reservoirs in the second quarter of 2007, has been producing 2,200 b/d, natural, from a single zone. Production is trucked to Toroyaco field facilities.

Production facilities are under construction at Uchupayaco, and a 15-km, 8-in. pipeline from Costayaco to Uchupayaco is to be completed in mid-2008.

Results of a 70 sq km 3D seismic survey over Costayaco field will be used to plan 2008 well locations.

Working interests are Gran Tierra and Solana Resources Ltd. 50% each.

Colombia - Catatumbo basin

Benchmark Energy Corp., Calgary, struck a deal with Colombia’s state Ecopetrol to apply proprietary well-performance enhancement technology to wells in three mature fields in the Catatumbo basin.

The wells are in Sardinata, Petrolea, and Tibz fields. A pilot project on the first Sardinata well started Dec. 9. All pilot projects are to be completed within 45 days.

Upon completion, assuming Ecopetrol is satisfied with the pilot results, Benchmark will attempt to negotiate a farmout from Ecopetrol on one or more of the fields.

Benchmark secured the preferential right to the technology for Colombia through a cooperation agreement with Dominion Oil (USA) Corp., Spring, Tex.

Colombia - Llanos basin

Petro Rubiales Energy Corp., Vancouver, BC, has boosted production from Rubiales field in the Llanos basin to 25,000 b/d from 18,300 b/d since taking control of the field in July 2007.

Results from the first three of 10 planned appraisal wells indicates that the reservoir extends farther southeast than originally thought.

RPS Scotia, Houston, formerly Scotia Group Inc., is conducting a reserves certification. The company anticipates that the results from the three wells will enable 85 million bbl of oil to be reclassified as proved reserves.

Falkland Islands

BHP Billiton Petroleum acquired 40% interest in 14 exploration and production licenses off the Falkland Islands.

BHP will operate the East Falkland basin licenses after having acquired the interests from Falkland Oil & Gas Ltd. FOGL holds the other 60% interest.

The licenses, south and east of the islands, cover 18 million acres in 656-6,570 ft of water.


Serica Energy PLC said the Global Santa Fe 136 was spudding the Batara Ismaya-1 exploration well in the Biliton Block in the Java Sea off Indonesia.

Next the rig will drill an exploration well on the Batara Indra North prospect.

Serica is operator of the Biliton PSC with 45% interest, and a farmee is carrying the majority of its costs in the two wells.


Otto Energy Ltd., Perth, agreed to participate with Deltana Energy Ltd., Sydney, in a farmout from Ascent Resources PLC of 50% interest in the 828 sq km Cento and Bastiglia exploration permits in Italy’s Po Valley.

The first of two wells is to be drilled in late 2008 on the Gazzata Prospect, estimated to be capable of containing more than 100 bcf of gas. Deltana and Otto will pay 100% of the cost of the first exploration well and 100% of the cost of a second exploration well if the first well finds commercial gas.


Sterling Resources Ltd., Calgary, was to spud an exploratory well on the Doina Sister prospect in mid-December in the northwestern Black Sea off Romania.

The prospect is an analog to the Doina gas discovery, which tested gas at a restricted 17 MMscfd.

The company said the established Doina gas trend forms a small part of the offshore Midia Block XV. Media Block XV and the Pelican Block XIII cover 1.1 million acres and contain several other mapped structures.

Sterling obtained 100% of the offshore blocks in 2006 and later reached agreement with three companies to cover its costs to drill and test the Doina Sister well and a large portion of a second well. Sterling retains a 65% working interest in the blocks.


Tower Resources PLC launched a 300 line-km 2D seismic survey on Block 5 in Uganda’s Albert graben.

The survey area overlies a sedimentary sequence with prospective structures identified by a regional gravity survey (see map, OGJ, Sept. 4, 2006, p. 46).

The survey is being shot under terms of an Aug. 28 agreement between Tower and Orca Exploration. On receipt of the fully interpreted seismic, Orca has the right to acquire a 50% working license interest in Block 5 by funding 83.33% of the cost of two exploration wells. The search for a rig is under way


Richards Oil & Gas Ltd., Calgary, drilled a multilateral horizontal well to the Ardley coals (Cretaceous Scollard formation) on its Ansell property in west-central Alberta.

Using an experimental “dry” drilling process, the company extended the original 50-m leg drilled in July 2007 into a further two legs totaling 350 m.

The company released the rig and plans to attempt completion, stimulation, and flow testing in the next two months.

Northwest Territories

Indian and Northern Affairs Canada issued a significant discovery license for Umiak field northwest of Inuvik, NWT, for which MGM Energy Corp., Calgary, is considering development scenarios to feed the proposed Mackenzie Valley gas pipeline.

The Umiak SDL covers 21,270 acres around the Umiak N-05 and N-16 wells and includes multiple pools of gas, oil, and oil and gas in Tertiary Richards and Taglu sandstones.

The company’s contingent resource estimate is 444 bcf of gas, which could supply at least 100 MMcfd for 10 years, and further volumes of oil in place.

MGM operates the field with 60% working interest, and ConocoPhillips Canada has 40%.


Penn Virginia Corp., Radnor, Pa., plans to ramp up horizontal drilling to Cretaceous Selma chalk in 2008 after a horizontal well in Baxterville field, Lamar County, Miss., exceeded expectations, the company told investment analysts in early December.

Another horizontal chalk well in Gwinville field, Jefferson Davis County, met expectations. The company believes horizontal drilling will hasten production and increase recoveries.

The formation is at about 6,000 ft, and vertical wells are being drilled on 20-acre spacing for reserves of 375-400 MMcf/well.

Penn Virginia’s third quarter gas production from Selma chalk averaged 21.9 MMcfd, up 29% on the year. It had 132 bcf of proved reserves in the formation at the end of 2006 and added 11.2 bcf of proved reserves in a 2007 acquisition at Gwinville.

The company was to drill 72 wells in 2007 compared with 80 wells in 2006 with 100% success.

Texas - West

Arena Resources Inc., Tulsa, found near virgin pressures of 1,500-1,800 psi in two wells recompleted for gas from Permian Yates at 3,000 ft in giant Fuhrman-Mascho oil field in Andrews County, Tex.

By early November, Arena had assured mechanical integrity at 18 of the first 20 wells it identified for recompletion in the Yates.

Arena in June 2007 agreed to dedicate its Yates gas on 14,000 acres to Aspen Pipeline, Houston, which plans to build and start up in mid-2008 a pipeline from the field 30 miles to the 1,000-Mw Odessa electric generating plant operated by PSEG Texas, Dallas, formerly Texas Independent Energy.

Under the agreement, Arena would recomplete or drill 60-90 wells/year for 4 years in an attempt to attain deliveries of 31-37 MMcfd. The Odessa plant can consume a blend that includes Yates gas, which has a high nitrogen content.

Arena has drilled more than 200 wells to the field’s oil producing formation at 4,800 ft and run refracs on more than 100 since acquiring the properties.

Texas - Offshore

Carson Energy Inc., private Austin independent, acquired a minority working interest in the Dorado development prospect, State Tract 133-1 prospect, in Galveston Bay.

The prospect is on leases adjacent to the Dorado ST 132-1 well, in which Carson Energy holds an interest. The well found multiple productive intervals and is producing 3.2 MMcfd of gas and 130 b/d of oil.

The acquisition adds to Carson’s portfolio of wells and 3D prospects in Trinity and Galveston bays through various operators that focus on deep Frio and Vicksburg intervals.


Range Resources Corp., Fort Worth, and Equitable Resources Inc., Pittsburgh, placed on production at 1.1 MMcfd of gas Virginia’s first horizontal Devonian shale well.

The well, in Nora field in Dickenson County, wend to TD 8,150 ft measured depth including a 3,000-ft lateral. Well cost was $1.2 million.