New lease on Beryl

Apache’s FNT development may appear a bit “vanilla” on the surface, but a fit-for purpose and fast-to-first-oil ethos under the Apache Projects Group Mission Command management system meant the difference between production and stranded reserves. Elaine Maslin reports.

Work offshore during the FNT project. Images from Apache.

Stranded pools are an endemic issue on the UK Continental Shelf (UKCS). Resources are left untapped because they’re either too small or too challenging to tap.

Apache’s Far North Triassic (FNT) project could have befallen such a fate, but by fast-tracking the project and keeping costs down – lean is an Apache North Sea mantra – it was brought online economically and just 11 months after the project team got their hands on it.

FNT is effectively an infill well in the Beryl field, which Apache bought from ExxonMobil in late 2011. After years without any new seismic data acquisition in the Beryl area, Apache shot new seismic and set about finding previously untapped resources, such as FNT.

The resource was originally drilled from the Beryl Bravo platform, with the plan being to produce it via a platform well. But, geographically difficult hole conditions, in what was a 22,000ft-long well, meant the firm had to re-think its plans.

“The Projects Group was challenged with finding a way to develop the field via a subsea tieback that could be economically justified rather than P&A (plug and abandon) the well,” says Mark Richardson, North Sea Projects Manager. The Projects Group delivered the full facilities for US$31.7 million (£26 million) (over 50% lower than UKCS benchmarked costs), including a tie-in point for future subsea tiebacks, in a record time. Making FNT a very successful economic development.

Not so vanilla

The FNT development comprises a 4km-long single well subsea tieback to the Beryl Bravo platform. It uses an 8in insulated production flexible, a 4in non-insulated gas lift flexible and a control umbilical, for hydraulic, electric and chemical supply to the subsea Xmas tree, plus a new subsea control system and modifications to the topsides.

The decision to develop came in early May 2015 after drilling the well, and initial engineering followed in June 2015. Offshore installation campaigns (route survey, pipeline installation, rock dumping then tie-in), conducted by Subsea 7, came next in February-March 2016, with first oil achieved on 26 April 2016.

The project was executed using the Apache “Mission Command” approach. This means that the mission and tasks were clearly defined, boundaries set, and resources allocated. A competent and capable, but lean, project team (five personnel) was allocated and given complete accountability, and tasked to work with a sense of urgency, collaborate with the supply chain and provide a safe fit-for-purpose solution.

“The remit was to get it online as soon as possible, as time spent on over optimization could eat into returns,” says Crawford Brown, Project Manager, Apache. “A few things came together to allow us to do that. Especially, the current supply chain environment, which definitely worked in a number of ways to our advantage. There was an appetite to respond to our cost challenges, lead time and approach, key factors in delivering best in class results.”

The appetite to work meant, despite February not being the most favorable time of year to do offshore construction work in the North Sea, it went ahead as soon as the subsea equipment was ready.

Procurement was also about being pragmatic and fit-for-purpose, which enabled use of an already manufactured flexible that was built in the UK for an Apache (now Quadrant Energy) project in Australia, but not shipped or used. The re-use of existing designs for the subsea controls system and other ancillary equipment, which had previously been developed for other projects, saved engineering hours. Valves installed for possible tie-ins were also already in stock, having already been ordered for another Apache project.

The firm also deemed it possible to re-use an existing riser, left redundant after the Linnhe tieback was shut-in, for the production line; and, after thoroughly inspecting both, to re-use a former export riser and existing J-tube to pull-in the gas lift pipeline and umbilical.

“We wouldn’t have specified that flexible for the gas lift line, if we were designing new, but it was fit-for-purpose and using it was a tenth of the cost of a new one,” Brown says. It also meant reducing lead time to as good as zero – a key benefit. A similar approach was looked at for an umbilical, but this time a product within Apache didn’t match the requirements. “Being able to make those decisions is good, but being able to make them quickly is vital,” Brown adds. “The main advantage (for Apache) of using already specified equipment was the schedule.”

When it came to repeat orders, while some of the equipment may have been over specified for what was needed, because the design requirements were reduced and the supplier was set up ready to manufacture, the overall costs were less and delivery faster, Brown says.

The Beryl field layout.

Future

Meanwhile, the firm is also developing other recent discoveries: Callater, a significant six-well slot bundle tieback to the Beryl Alpha facility, discovered in 2015; North West Beryl 3 (NWB3), a tieback to the Ness/Nevis subsea infrastructure; plus a Skene North well tie-in to the Skene bundle, all of which are due online in 2017.

There is also Corona, a heavy oil development tapping Tertiary injectites, which surrounds the Beryl field, also tying into Beryl Alpha, due online in 2019. Then, there is Seagull, a high-pressure, high-temperature tieback, which is in pre-front-end engineering and design with host solutions being assessed.

This year [2017], Apache will continue its highly successful, exploration, appraisal and development drilling (in 2015 Apache found 50% of the new reserves in the UKCS). Two semisubmersible drilling rigs will be at work, Apache has plans to drill Skene North and then Callater wells, plus some exploration targets. Platform rigs will also be active in the Forties and Beryl fields.

The Apache Projects Group Mission Command, lean, fit-for-purpose approach will also be taken towards these future projects. Keeping costs low, delivering safely with a sense of urgency, finding new fields and developing stranded oil is what Apache does best.