The Parque das Conchas complex has completed a full decade of production for Shell off Brazil, and while the Anglo-Dutch supermajor has been focusing lately on upstream activities in the prolific pre-salt province to unlock potential giant discoveries, the Campos basin deep-water development still plays a vital role in the company’s operations in the country.

Parque das Conchas, also known as BC-10, remains the company’s largest operated production asset in Brazil, and Shell continues to pour money into the field in an attempt to keep output at sustainable levels.

After a five-year hiatus, Shell resumed exploration drilling in Brazil in April with an infill programme in BC-10 in over 1600 metres of water using the Constellation Oil Services drillship Brava Star.

“Two wells have been drilled, but we continue to look for opportunities in the reservoir to deliver more barrels and improve our recovery factor,” says Shell BC-10 operations manager Mandy Lewis.

The first well came on stream in July in the Argonauta O-North field and is producing about 3500 barrels per day of oil, higher than originally expected, according to Lewis. The second well was due to enter operation this month in the Argonauta B-West field with a similar flow rate.

“BC-10 is currently producing in the upper 40,000 bpd, but with the new wells online, output should increase to mid-50,000 bpd,” she tells Upstream.

“Over the long term, our strategy is centred on continuing delivering value by drilling new infill wells to try to sustain production at between 35,000 bpd and 40,000 bpd. Our focus is on existing reservoirs and how we can optimise the pockets in the reservoirs that are not fully depleted.”

Peak

Shell, which operates BC-10 with a 50% stake, started production in the area in July 2009 via a phase one development of the Ostra, Argonauta B-West and Abalone fields.

Output peaked in October 2010 at 86,000 bpd from 10 wells linked to the SBM Offshore-owned Espirito Santo floating production, storage and offloading vessel.

Three years later, Shell brought on stream a second phase by adding production from the Argonauta O-North field, and finally on March 2016 a third phase kicked in comprising the Massa and Argonauta O-South fields.

Lewis explains that managing simultaneously six different fields, which have already produced more than 160 million barrels of oil, is a more intricate process than it might appear.

The Parque das Conchas cluster is a mixed bag as reservoirs and fluids run to both ends of the spectrum, with oil ranging from 15.8 degrees API at Argonauta B-West to 42 degrees API in Abalone. “There are a lot of challenges on the subsea side related to flow assurance. The subsea kit in BC-10 is extremely complex and there is also the issue on the topsides when all these types of crude come together, and not all play well with each other,” says Lewis.

“Abalone has light oil and is also a gas producer. Massa is slightly heavier with high carbon dioxide content. Ostra is a lovely type of crude with very good viscosity and easy to pump, while oil in Argonauta O-North is very heavy and viscous.”

Shell is understood to be analysing the possibility of drilling more wells in the Ostra field following a 4D seismic survey conducted in late 2017.

Even though Shell is relying on infill drilling to keep driving production up at BC-10, the company is also looking at opportunities to bring Abalone back online.

The Abalone field was producing from a single well when a problem at one of the safety valves forced Shell to interrupt output in mid-2011 to carry out extensive maintenance.

Lewis says: “We did conduct well intervention in Abalone in late 2018 and we are now working towards the flow plan for how we are going to operate it.

“Abalone has a high gas-to-oil ratio. It is a huge gas producer, so we need to make sure we deliver it safely within the main gas compressor constraints to avoid flaring.”

The BC-10 concession licence expires in 2032, but Shell hopes to secure an extension with the Brazilian National Petroleum Agency to continue producing for a lot longer. In order to produce for many more years to come, Shell has started conversations with several vendors to see what technologies are available in the market to handle the potential problems of dealing with growing levels of water in the reservoir.

“After 10 years of production, we are seeing more and more water coming to the FPSO, so as BC-10 becomes a more mature asset, it will bring all sorts of challenges from an asset integrity perspective,” highlights Lewis. “From a produced water handling perspective, it is not a bottleneck right now, but we absolutely see that could be a constraint for our topsides in the future, so we kicked off a full study to see what we are going to do next to be able to de-bottleneck the facility that handles the produced water.”

While these studies are still in a conceptual phase, she adds Shell is trying to be prepared to conduct some de-bottlenecking activities next year to deal with produced water and pave the way for future work at BC-10.

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Parque das Conchas at heart for Shell off Brazil