The Tors development consists of 2 gas fields, Kilmar in Block 43/22a and Garrow in Blocks 42/25a and 43/21a.

Kilmar was discovered in 1992 and has gas in Carboniferous Namurian sandstones. Alpha acquired 100% equity from BP (2001) and GDF (2004), subsequently selling interests to Sojitz (2005) and Edison (2008).

Garrow was discovered in 1991 and has a Rotliegend reservoir. Garrow was an out of round award to Alpha in 2002 and equity was subsequently sold to Sojitz (2005) and Edison (2008) First gas production was achieved in 2006. The gas is exported via Trent and the ETS pipeline to Bacton, Norfolk.

The Kilmar Normally Unmanned Installation (NUI) was installed in 2005, a 6 slot platform. 3 wells have been drilled and, up to end of 2015, 60 bcf of gas has been produced.  There is an estimated 40 bcf of recoverable gas remaining.

An inline water separator was installed on the Kilmar platform in 2012 to handle the water produced from the K3 production well. Kilmar is a large structure and the 3 wells do not access all of the calculated gas in place. Future work on Kilmar will be to identify potential infill locations.

The Garrow NUI platform was installed in July 2008.This is a 3 slot platform, two production wells have been drilled and, up to end of 2015, 6 bcf of gas had been produced.  Remaining recoverable gas is estimated at 4 bcf.