The well abandonment

The two-step back filling of the well Ktzi 202

On August 29, 2013, according to schedule, the GFZ German Research Centre for Geosciences terminated the five-year injection of carbon dioxide (CO2) near the town Ketzin/Havel in the State of Brandenburg.

Still before the deconstruction of the injection facility in December 2013 the step wise closure of the observation well Ktzi 202 started. The lower part of the well was already abandoned in autumn of 2013 to a depth of approximately 520 m with CO2-resistant cement; up to now, this first abandonment step was scientifically monitored by continuous measurements.

On June 29th, 2015, a core sample of this first cement bridge for assessment of the backfill material was taken. After positive testing of the material the complete abandonment of the upper well portion of the Ktzi 202 is planned now within the following days. Therefore, on June 30th 2015, a mechanical closure system (bridge plug) was installed in the well in about 480 meters, above the lower part of the abandonment. Thereafter the 5 ½ tubing was cut above the cement plug in 459 meters and removed. Then the well was filled with cement from the cement plug up to about 275 m. After the curing of the cement at the weekend the next tubing will be cut at about 265 m and removed. Afterwards the well will be completely filled with cement up to ground level. After dismantling of the drilling rig, the deconstruction of the rig cellar and the foundation can begin.

In 2016, it is intended to abandon the four other research wells at the Ketzin pilot site, in order to complete the entire life cycle of the CO2 storage at Ketzin - from construction to site closure.

Press Release of GFZ: