Improving Shale Gas Safety with Well Integrity Management
Written by Intetech’s Dr Liane Smith
The recent approval of shale gas extraction by ministers in the UK means that operations are now planned to start in 2015. Shale gas has the potential to make a significant contribution to ensuring energy security and reduce the UK’s reliance on imports.
But while business leaders are enthusiastic about shale gas and its potential to boost industry and keep energy costs down, environmentalists are more cautious. The extraction process entails hydraulic fracturing (fracking), which has proved controversial. Incidents in the US have seen fracking associated with pollution of water through the chemicals involved, while the UK Government imposed a moratorium on the practice 18 months ago after the UK’s first fracking site was found to have caused two minor earthquakes.
Well integrity the highest priority
The UK Government’s Chief Scientific Adviser, Sir John Beddington FRS, asked the Royal Society and the Royal Academy of Engineering to review the scientific and engineering evidence and consider whether the risks associated with fracking as a means of extracting shale gas could be managed effectively in the UK.
Published in June 2012, the review concluded that the health, safety, and environmental risks can be managed effectively, and that the risk of fractures propagating to reach overlying aquifers is very low. It also concluded that more likely causes of possible contamination include faulty wells. Well integrity was therefore identified as being the highest priority, with robust monitoring also considered vital before, during and after shale gas operations.
Managing well integrity is therefore much more than simply ensuring safety during a current activity or specific scenarios, rather it concerns the sustainability of the equipment to operate safely for the full design life of the well. Well integrity management systems exist both at a documentation and software level, and combine key well operating and production data within a framework for decision-making, management processes and organisational structure.
The shale gas opportunity
Because the shale gas sector is still young, it can learn much from the conventional oil and gas business in terms of best practice, but firms also have the opportunity to take the initiative on well integrity management, given that conventional players are only just beginning to implement more systemised approaches. Well Integrity Management System (WIMS) documentation sets the standard in terms of helping to set out and establish an approach for all aspects of well life – from design and construction, to operation and abandonment – and for all well types.
However, much of the information relating to well production, barrier equipment and design is held in different departments in various formats and under different timelines. Not only do these ‘silos’ make it difficult for senior executives and management teams to collate, compare and report on well integrity data, but the length of time this can take impacts on their ability to identify problem wells, make informed decisions and take remedial action.
A systemised approach
When a shale gas well is drilled, the well bore is protected by a steel casing, with the space between the steel casing and the rock wall in the well bore filled with cement. Known as a ‘cement sheath’, the protection of this sheath is essential in order to prevent contamination.
The normal deterioration mechanisms are to be expected – namely temperature and pressure fluctuations due to changes in production rates. These can cause potential degradation of the cement bond between the casing and the cement, or the well bore and the cement.
Additionally, the fracking process itself is unique, in that a large volume of high-pressure fluid is being pumped into the well bore for prolonged periods, stressing all the cement bonds, or any kind of mechanical or integral seal within the well. Given the potential for a loss of integrity over time, the cement sheath and surface conditions must be monitored continuously. The operator must also ensure vigorous fluid quality monitoring. Shale gas requires large amounts of water, if the water needs to be reused during the process then the quality of the water must be assured.
An advanced well integrity management system provides the ability to analyse, compare and validate all operating well data, alert and report on exceptions and make information available throughout the enterprise to the right people at the right time. It provides:
Production information – to confirm that all fluids in the well are within their safe operating limits for flow rates, pressures and temperatures
Barrier tests – to check that safety-critical equipment is leak-free
Well design data –to support informed well workover plans
Well history – to track all actions on the well and handover events
Practical steps for shale gas
The performance of shale gas wells should be monitored as per conventional wells in order to detect signs of leaks at an early stage. This ensures that action can be taken to control them in a timely way, rather than waiting until any aquifer has become contaminated or other problems.
Operators also need to monitor fluid compositions at the wells and in surrounding aquifer monitoring wells to reassure the public of diligence and quality control of their potable water. There are three crucial steps to this process: sample the well data, record that data and ensure control mechanisms that keep operations within defined safe operating envelopes.
To date, there has been too much focus on the fracking process, and not enough on managing the integrity of the completed wells themselves. With all departments and risk areas integrated into a single, highly-functional well integrity management system, operators can have access to a single version of the truth that translates into usable information for proactive decision-making. More importantly, by taking the lead on well integrity, shale gas operators will not only ensure integrity is established and maintained effectively, but can be seen to be doing so by both regulators and the general public.
Image sourced via danielfoster437
Ofwat allows retailers to raise prices from April
Retailers can recover a portion of excess bad debt by temporarily increasing prices from April 2022, according to an Ofwat statement.
The regulator confirmed its view that levels of bad debt costs across the business retail market are exceeding 2% of non-household revenue, thereby allowing "a temporary increase" in the maximum prices. Adjustments to price caps will apply for a minimum of two years to reduce the step changes in price that customers might experience.
Measures introduced since March 2020 to contain the spread of Covid-19 could lead to retailers facing higher levels of customer bad debt. Retailers’ abilities to respond to this are expected to be constrained by Ofwat strengthening protections for non-household customers during Covid-19 and the presence of price caps.
In April last year, Ofwat committed to provide additional regulatory protection if bad debt costs across the market exceeded 2% of non-household revenue.
Georgina Mills, Business Retail Market Director at Ofwat said: “These decisions aim to protect the interests of non-household customers in the short and longer term, including from the risk of systemic Retailer failure as the business retail market continues to feel the impacts of COVID-19. By implementing market-wide adjustments to price caps, we aim to minimise any additional costs for customers in the shorter term by promoting efficiency and supporting competition.”
There are also three areas where Ofwat has not reached definitive conclusions and is seeking further evidence and views from stakeholders:
- Pooling excess bad debt costs – Ofwat proposes that the recovery of excess bad debt costs is pooled across all non-household customers, via a uniform uplift to price caps.
- Keeping open the option of not pursuing a true up – For example if outturn bad debt costs are not materially higher than the 2% threshold.
- Undertaking the true up – If a 'true up' is required, Ofwat has set out how it expects this to work in practice.
Further consultation on the proposed adjustments to REC price caps can be expected by December.
"While it’s great that regulators are helping the industry deal with bad debt in the wake of the pandemic, raising prices only treats the symptoms. Instead, water companies should head upstream, using customer data to identify and rectify the causes of bad debt, stop it at source and help prevent it from occurring in the first place," she said.
"While recouping costs is a must, water companies shouldn’t just rely on the regulator. Data can help companies segment customers, identify and assist customers that are struggling financially, avoiding penalising the entire customer in tackling the cause of the issue."
United Utilities picks up pipeline award
A race-against-time plumbing job to connect four huge water pipes into the large Haweswater Aqueduct in Cumbria saw United Utilities awarded Utility Project of the Year by Pipeline Industries Guild.
The Hallbank project, near Kendal, was completed within a tight eight-day deadline, in a storm and during the second COVID lockdown last November – and with three hours to spare. Principal construction manager John Dawson said the project helped boost the resilience of water supplies across the North West.
“I think what made us stand out was the scale, the use of future technology and the fact that we were really just one team, working collaboratively for a common goal," he said.
Camus Energy secures $16m funding
Camus Energy, which provides advanced grid management technology, has secured $16 million in a Series A round, led by Park West Asset Management and joined by Congruent Ventures, Wave Capital and other investors, including an investor-owned utility. Camus will leverage the operating capital to expand its grid management software platform to meet growing demand from utilities across North America.
As local utilities look to save money and increase their use of clean energy by tapping into low-cost and low-carbon local resources, Camus' grid management platform provides connectivity between the utility's operations team, its grid-connected equipment and customer devices.