ID: 689
OBJECTID: 689
wlbNpdidWellbore: 1508
wlbName: 1/6-5
wlbHistory:

General

Well 1/6-5 is located in the Feda Graben between the Flyndre and Tommeliten Gamma discovery in the North Sea. The well was drilled on the crest of a major salt diapir. The objective of the well was to test the existence of a chalk raft and the presence of reservoired hydrocarbons.

Operations and results

Wildcat well 1/6-5 was spudded with the semi-submersible installation Dyvi Stena on 20 July 1990 and drilled to TD at 1854 in Late Permian salt of the Zechstein Group. An 8 1/2" pilot hole was drilled from 156m to 600m. The hole was control drilled at 30m/hr maximum ROP as a precaution for encountering shallow gas. No shallow gas was encountered. Pore pressure prediction while drilling in the 1/6-5 well was difficult as the only pore pressure detection parameters that appeared to work were gas measurements, resistivity and sonic log measurements. Other parameters such as shale cuttings density, Electric log density, D-exponent and rate of penetration were not successful in determining high pore pressure zones. However, despite the abnormally high pressures and temperatures encountered drilling went forth without major incidents. A minor salt water flow accompanied by a 37.1 % gas peak occurred during a trip at core point at 1725 m. The mud weight was increased from 15 ppg to 15.3 ppg and finally 15.5 ppg as a result of this flow. In the following coring 119 bbls of mud was lost to the formation, but this was cured by setting an LCM pill. The well was drilled with seawater and viscous pre-hydrated bentonite sweeps down to 600 m and with fresh water polymer mud/Duponol WBS 200 wellbore stabilizer from 600 m to TD.

From 864 m gas readings showed all components from C1 to C4. Gas peaks from the formation were experienced all
wlbHistoryDateUpdated: 2016-07-06T00:00:00