15/12-13 A

General

Well 15/12-13 is located ca 0.8 km northwest of the 15/12-12 (Varg South) Discovery well. The primary objective was to appraise the Varg South discovery: to define the oil/water contact, measure current reservoir pressure and fluid gradients, confirm reservoir quality and geometry, and confirm geophysical model in terms of depth to top and base reservoir. Potential Kimmeridgian Sandstone immediately above the main Oxfordian reservoir was seen as a secondary objective. The well bore 15/12-13 encountered the Oxfordian sandstones (Intra Heather Formation sandstone) 105 m deeper than the prognosed reservoir, and below the OWC. Since the objectiv of this well was not met well 15/12-13 A was drilled as a geological sidetrack to 15/12-13. The geological target was the same as in the primary well bore, but ca 300 m southwest of the discovery well 15/12-12.

Operations and results

Appraisal sidetrack well 15/12-13 A was spudded with the semi-submersible installation West Alpha on 11 May 2003. Kick-off was at 1350 m. The well was drilled to 2530 m, when the BHA became stuck repeatedly due to poor hole cleaning and the fact that the formation was reacting with the mud. The well bore was drilled with Sodium silicate (Barasil CX)/KCl/glycol mud. The well bore was logged with LWD only. No wire line logs were run, no pressure or fluid samples were taken, and no cores were cut.

The sidetrack was abandoned in favor of a lower angle sidetrack along a different azimuth. It was permanently abandoned on 17 May as a junked well.

Testing

No drill stem test was performed.