Cairn Makes Discovery with First Well on Mangala Prospect

Cairn announces the successful results of the first appraisal well on the Mangala oil field in northern Rajasthan.

Mangala-1ST was drilled from the N-B-1 discovery well surface location and deviated 400 meters away in an up-dip direction. The well cored 234 meters of gross Fatehgarh section and encountered 121 meters net (equivalent to 109 meters net true vertical) of excellent quality oil bearing Fatehgarh sands. The same oil water contact and pressure system has been found in both wells.

A vertical reservoir interference test was conducted between N-B-1 and Mangala-1ST to assess reservoir continuity and connectivity between the two wells. Oil from a zone in N-B-1 was produced and the pressure disturbance measured in sands within Mangala-1ST. The result successfully established reservoir connectivity between the two locations. Further interference testing on future appraisal wells will also be required to determine connectivity across the field for development purposes.

Two sand units were also selected for an open hole drill stem test program in Mangala-1ST. The first zone tested (Zone 1) was from a selected interval within a massive sand unit which was water bearing in the discovery well. The second zone tested (Zone 2) was the structurally highest Fatehgarh sand yet encountered in the field.

The following stabilized rates were obtained in the open hole tests:

  • Zone 2 tested at 1,250 barrels of oil per day of 30 degrees API oil on a 56/64 inch choke.
  • Zone 1 tested at 2,800 barrels of oil per day of 27 degrees API oil on a 2 inch choke.

  • Three additional appraisal wells will be drilled from new surface locations 2.5 kilometers, 1.5 kilometers and 3 kilometers respectively from N-B-1.

    Additional Exploration Activity

    Operations on exploration well N-F-1 commenced on March 20, 2004. Operations on the Saraswati-4 appraisal well have been temporarily suspended to allow the drilling rig to be moved north to the N-C exploration prospect. The N-C-1 exploration well is expected to commence drilling in early April.

    A 2D seismic program across the northern area is also underway.

    Bill Gammell, Chief Executive, commented:

    "I am delighted with this excellent start to the Mangala appraisal program which is consistent with our views of the potential of the field."