CUSTOMER: Tegichevroil (TCO) Oil and Gas Refinery Kazakhstan

PROBLEM: Mechanical damage to the 28 inch main feed pipeline at the  Tegichevroil (TCO)-operated oil and gas refinery in Kazakhstan was causing gas losses, and remedial work was required as a matter of urgency.   It was imperative that shutdown was avoided as this would mean cutting off gas supplies to numerous cities and areas of industry and incurring significant costs.

SOLUTION: Furmanite was called in for its specialist on-line pipeline intervention skills in order to avoid a shutdown of several days.  A new double block and bleed valve was installed at the point where the line was damaged.  This involved hot tapping the three ancillary balance, vent and bagging points in the 28 inch pipe line through flange on weld-o-lets (supplied by Furmanite and welded on site) and cutting the 28 inch pipe through a pre-fitted full encirclement tee to allow insertion of the stopple plug.  All this was performed under normal operating pressure of 43 bar g.  Furmanite technicians vented the line through the vent point and the refinery boiler house and back-purged it with nitrogen from the refinery.  Two bags were then inserted in to the line and filled with nitrogen, acting as secondary stops.  This held the line, without leakage, for eight days while the technicians focused on the pigging 60km downstream. 

Modification of the pigging station entailed removal of a large section of the pigging system and its replacement with a more up to date unit.  The same operation was carried out as had been undertaken upstream, (although on a 16 inch line on one side of the station).  Work was successful and live gas pressure was maintained while the remedial work was carried out.

OUTCOME: Furmanite's pipeline intervention expertise allowed the remedial works to the pipeline and pigging station to be carried out safely, the work successfully completed, and the line reinstated on schedule.  The entire project was carried out without shut down, avoiding the need to import extremely expensive gas from an outside source to meet consumer demand.