Pumping under pressure

The UK is ‘going all out for shale’. Those were the words of prime minister David Cameron at the start of the year as he attempted to shore up support for ‘fracking’ — a controversial technique that he believes could help solve the country’s impending energy crisis.

Fracking — or hydraulic fracturing — involves shattering rock deep  in the Earth to release shale gas using high-pressure water, sand and chemicals. Its use has prompted fierce opposition from some sections  of the public over fears that it could trigger earthquakes and release damaging chemicals into the environment. But while the debate on fracking continues to rage in the UK, engineers in the US are developing technologies that could extract shale gas from increasingly difficult geological formations. The country has undertaken fracking in at least  17 states with more than 82,000 wells operating nationally.

The success of the shale industry owes a great deal to innovation in the pumps used to deliver fluid down to the well bore, as well as the growing supply chain. Early frac pumps were either triplex or quintuplex, operating with three or five pistons. They were used on vertical fracturing operations and typically ranged in horsepower capacity from 1,300–2,000bhp with pressure requirements often less than 10,000psi.

These pumps were fine in the early days of shale gas extraction, but as engineers looked further afield, pumps had to evolve to be bigger, stronger and more reliable. This evolution began two decades ago during the boom in unconventional shale natural gas plays. The most notable was the Barnett Shale formation in north Texas, which used a technique known as horizontal drilling.

Horizontal drilling allows engineers to access more natural gas from thin shale deposits. The pumps needed to do this had to be capable of operating for more than eight hours at a time. ‘Initially, the power of the pump for the water used to fracture the rock was weak and we needed to combine chemical substances to enhance the viscosity of the water to propel the sand further,’ said Hiroki Haba, vice-president of the shale gas division at Mitsubishi Corporation.

For a sector traditionally conservative in its approach, the pumps market moved relatively quickly to address the problem. ‘Performance under those conditions required innovation in creating a new robust pump with structural integrity to meet the demand of high-pressure conditions,’ said Chris Poole, executive vice-president of engineering at Weir. In response, Weir spent three years developing the Destiny TWS 2500. The pump offered a load capacity of 273,000lbs and 2,500hp. It also required far fewer duty cycles and therefore experienced less wear. But even greater reliability and flexibility were needed, as pumps went from operating from an average of eight hours to several days at a time. This led to a new generation of ‘super duty’ pumps designed specifically for tough unconventional gas plays, such as Baker Hughes’ Centrilift FLEX pumps.

As frack pump technology in the US evolved, so too did the companies that delivered solutions. In comparison, some in the industry believe that a lack of an existing supply chain in the UK could prove to be a barrier in maintaining British innovation in what could be a lucrative industry. The government currently estimates that up to 2,880 wells could be drilled for oil or gas in a new licensing round, which would in turn generate 16,000–32,000 jobs.

But without a supply chain in place, innovations such as super-duty pumps are more likely to come from abroad. ‘Vast shale gas reserves across Europe and the economic benefits of shale gas exploration will encourage exploration,’ said Frost and Sullivan Industrial Automation and Process Control research analyst Niranjan Paul. ‘However, the potential growth of pump manufacturers targeting the region’s shale gas industry will vary according to the country.’

The UK has drilled around 2,000 wells onshore, including at Wytch Farm in Dorset, where British engineers have pioneered horizontal drilling techniques. Despite this, the country lacks an extensive onshore supply chain that could work on innovation in pump technology. Unlike the offshore sector, demand for onshore rigs and drilling services has been low. While innovation in pump technology in the US could prove to be a useful lesson, its success is unlikely to be replicated in the UK.

‘In the course of our research, we have spoken to a number of investors and potential investors who have told us that the lack of an onshore drilling services industry in the UK at present is an issue,’ said Corin Taylor, senior economic adviser at the Institute of Directors (IoD). ‘Less competition will mean higher prices for drilling than in the US, although UK wholesale gas prices are also higher.’

The UK oil and gas sector overall has a supply chain of more than 1,100 companies generating revenues of around £27bn. While there may be significant differences between offshore and onshore development, Taylor suggests the UK’s offshore expertise may be one solution to developing a much-needed supply chain.

‘We have the skills and we have the capability; it makes a lot of sense from a job creation and tax revenue point of view. We should get out there and prove the technology in a UK context, and use that as a platform to become a European hub as shale reserves are developed across both western and eastern Europe,’ Keith Cochrane, chief executive of Weir, said in the IoD’s recent ‘Getting Shale Gas Working’ report.

As the shale gas industry continues to grow over the other side of the pond, political uncertainties in the UK mean that the sector remains in its infancy. But the shale industry has proven that it can overcome technological and political barriers in its search for lucrative energy. But whether this will be enough to foster shale gas innovation in the UK remains to be seen.