ID: 122
OBJECTID: 122
wlbNpdidWellbore: 124
wlbName: 2/8-1
wlbHistory:

General

Well 2/8-1 was the eighth, and at the time the most southerly exploration well to be drilled in Norwegian waters. The geological objective of the well, in this early stage of exploration, was to test all horizons down to the Permian Rotliegendes Group. The well also had as a technical objective to test the use of a large, single hull vessel for drilling in the North Sea.

Operations and results

Well 2/8-1 was spudded with the vessel "Drillship" on 28 November 1967. This was the first drilling operation in Norwegian waters in which a vessel was used. Many problems arose during the drilling of 2/8-1. Repeated failures of the anchor mooring chains at tensions loads of only 10?50 % of their rated breaking occurred. To this, the weather conditions in the North Sea turned out to be more severe than had been predicted. Several storms in the 25 to 30 year category were encountered, and in January a storm that would be expected once every 75?100 years occurred with maximum waves of 15 - 17 m. After this storm the Drillship was in shipyard for repairs and modifications from 19 January to 8 March 1968. Even so, these failures of anchor chains eventually resulted in failure of the BOP stack and 13 3/8" well head after having drilled to 2595 m, and made clear that drilling could not continue safely.

Besides the mooring problems, other difficulties occurred. While testing in the 12 1/4" hole, the Drill Stem Test (DST) - tool dropped into the hole. The hole was reamed and the fish retrieved. The drill pipe stuck twice when making trips, first at 2118 m. The pipe was not recovered and a fish was left from 2007 - 2118 m. A cement plug was set and the hole side tracked. The pipe stuck again at 2237 m and a new fish was left from 2052 to 2237 m. Two cement plugs were set, one in the 13 3/8" casing shoe and one in the casing from 140 m to sea floor. This occurred in connection with the BOP and wellhead break, and th
wlbHistoryDateUpdated: 2016-05-19T00:00:00