Amoco reports big Norwegian Sea strike

Amoco Norway Oil Co. has disclosed an oil strike in the Norwegian Sea that it reckons could have reserves of at least 200-500 million boe.

Operator Amoco drilled a rank wildcat on Block 6507/5, on a structure called Donnatello that lies between the producing Norne and Heidrun oil fields.

The well was drilled with the Maersk Jutlander semisubmersible rig operating in 327 m of water, to a vertical depth of 4,198 m where it bottomed in an early Jurassic formation.

Well results

Amoco said the 6507/5-1 well encountered more than 140 m of net oil and gas pay in Jurassic and Cretaceous formations. Three separate drill stem tests were run.

Two tests in Jurassic sands flowed at rates of 5,400 b/d of oil and 5.3 MMcfd of gas through a 1-in. choke and 1,120 b/d of condensate and 26.2 MMcfd of gas through a 40/64-in. choke, respectively.

The company said that while uncertainty remains as to the Donnatello oil/gas ratio, preliminary estimates suggest reserves in the Jurassic formation alone could amount to 200-500 million boe.

The Cretaceous layer test produced 5,800 b/d of oil and 7.8 MMcfd of gas through a 36/64-in. choke. Amoco said 300 m of core were collected from the well and that other prospects on the license area are being evaluated.

L. Richard Flury, president of Amoco's exploration and production division, said, "This is a very encouraging discovery that may prove to be of great importance to Amoco in Norway as well as to Amoco Corp."

Block 6507/5 license interest holders are: operator Amoco 30%, state firm Statoil AS 30%, Enterprise Oil Norge AS 25%, and Mobil Exploration Norway Inc. 15%.

Enterprise model

Enterprise said it regards the Donnatello discovery as confirmation of its geological model for the play. Prior to drilling of the discovery well, Enterprise had increased its interest in nearby licenses.

Before the well was spudded in late December, Enterprise traded with Norsk Hydro AS to gain a 20% stake in Block 6507/3 to the north in return for 5% in Block 30/8 plus an undisclosed cash sum.

Before Donnatello was tested, Enterprise traded with Total Norge AS to gain a further 20% interest in Block 6507/3 in return for 10% in Block 30/8 plus cash.

John Bullough, general manager of Enterprise Norge, said, "This is a very significant discovery for our business in Norway, and we have taken steps to enhance our position in an area we believe has considerable potential.

"We will now seek to exploit our increased presence in the Norne-Donnatello trend to maximize the value of our assets. An initial step will be the appraisal of Donnatello, which we hope to begin in 1999."

When Block 6608/10 Norne was discovered in 1993, it was declared the largest Norwegian find in 8 years, with estimated reserves of 480 million bbl of oil and 550 bcf of gas. The field was developed with a production ship and now delivers 100,000 b/d of oil.