While carrying out a Plug and Abandonment (P&A) campaign on a UK North Sea oil and gas platform, several wells required a perf wash cement (PWC) to set a safe environmental barrier. PWC, as part of the abandonment process, involves perforating the casing, washing through the perforations and setting a cement plug through the casing to create a laterally extensive barrier from formation to formation.
Abandon the routine well in accordance to the Oil and Gas UK Abandonment Guidelines, the customers well abandonment manual and supplementary UK requirements.
The well was successfully plugged and abandoned using the WG003 340K HWU.
The Tubing hanger was pulled using a spear assembly and 10,000ft of 7" x 5-1/2" completion recovered. An 800ft cement plug was set in the wellbore at a depth of 8400ft. E-line was rigged up through the unit to set the 9-5/8" bridge plug. The PWC cement plug was set at 6000ft
To perforate zone was washed down with a pump rate of 7.5bbls/min at 600psi. Fluid returned to the shakers was monitored throughout the operation. On completion of the washes of the perforated zone, a bottoms up circulation was completed with the string rotated at 40rpm during the circulation. The spacer then pumped followed by the cement.