The DTS logging was started one to two days after completion of the respective well, and
continuous monitoring of the well temperatures was performed over a period of up to 61 days.
Government regulations for the abandonment procedure required that the wells be plugged
and the casing cut below ground level. In order to enable future temperature measurements,
the DTS cables were secured and left accessible during the abandonment of the wells. The
surface ends of the sensor cables were stored in custom-designed steel boxes on site. Two
subsequent DTS surveys were carried out for long-term temperature monitoring in October
2002 and September 2003 with a temporary set-up of the DTS equipment