Wellington, New Zealand

For the last two weeks I reviewed an offshore field in Wellington, New Zealand.  I had a fine time with some great colleagues and a challenging field.  Wellington is the definition of 'picture postcard' scenery.  Everywhere you look in this town you find something photo-worthy.  The town is built on hillsides which overlook an arm of the sea, but also it is clean (never really saw litter) and eclectic.  Small wooden houses and grand mansions compete for space on the sides of the hills.  Some houses have (and need) little cable cars from the driveway up the mountainside.  

We thought we might not need two weeks to review this field with only 7 producers and 3 injectors, but there was such interaction between the wells and facilities and there were so many competing issues that our Producing the Limit review took the standard 2 weeks and we were glad we took the time.  The team uncovered a looming restriction in the subsea flowlines that would have made production of new projects possible only by sacrificing production from the struggling, current wells.  There were a variety of options for reducing backpressure with additional volumes including multi-phase boosting, but since the ESPs already have very good downhole separation, flowing each phase separately through the subsea flowlines will dramatically reduce additional friction as the rates increase.  We also recommended with this approach to convert to wellhead metering using simple, reliable single phase meters, such as coriolis and vortex meters for liquids and gas.  This will give the field real-time rate measurements that will greatly help management of both the ESPs and the waterflood.  (Right now the operators are not able to get very many welltests and those are of short duration or done by testing wells together and finding individual production by difference--very prone to error.)  Also, in this field the average time to replace a broken ESP and return the wells to production was 43 days, while the workover itself was only 16 days.  Thus, proactive replacement of pumps would save 27 days of downtime on average compared to waiting until the pump fails. This alone is worth $50-100 million over the remaining field life. Other benefits for this approach are better planning for the workover rig and better forensics analysis on the retrieved pumps, which in turn will help increase their runlives.  

Recommendations are expected to increase production 25% and add a few million barrels to ultimate recovery.  

We also made a trip to the Weta Cave on the property of Weta, the special effects geniuses who did Lord of the Rings, The Hobbit, District 9 and other movies.   I turned into a kid for 3 hours.  What great fun!!!  

Gollum and Burney eye each other suspiciously

And, if you are a Lord of the Rings fan, watch this Air New Zealand safety briefing!!!!