Special Digest


Preese Hall - Has it leaked? Will it leak?

The first shale gas well to be fracked in the UK has an unfortunate history. Fracking this well caused earthquakes three years back, resulting in deformation of the well, and now new information has emerged of further problems with well barrier integrity. Whether this resulted in a well integrity failure has not been established.

On April 1st 2011 Cuadrilla fracked this well, named PH1, at Preese Hall, Fylde, Lancashire. This caused a seismic event which was felt in the nearby area.

They continued with a series of further tests (including DFIT or mini-fracs and 2 full fracks) until on 27th May there was a further larger (than the other 50 or so smaller events that were recorded) seismic event. The BGS knew now the quakes had a fingerprint which showed the new tremor was down to fracking. Although not as large as the April 1st tremor it was enough for the rug to be pulled from under Cuadrilla's feet. Despite the tremor, the NEXT DAY Cuadrilla CONTINUED with yet another DFIT and Frack. Even four days later they planned a further frack. But this was too much for the authorities. On the basis of the 27th May event there was a suspension of Cuadrilla's activities. During the investigation which followed it became apparent that the well casing at Preese Hall had been deformed by the April 1st tremor and Cuadrilla had known about it a few days after that event. However they did not disclose this information. In the report into the seismic events (the Green/Styles/Baptie report of April 2012) it is made clear that “Once wellbore deformation is observed, a detailed analysis is required in order to use the correct mitigating strategy, which may include either strengthening the casing, or alternatively, allowing more room for greater compliance between the casing and formation.”

Cuadrilla, however, determined unilaterally that there was no effect on overall well integrity and continued fracking. (It is not, therefore, clear why they then subsequently closed the well, if they had determined no loss of integrity). The official report concluded the earthquakes were indeed the overwhelmingly likely cause of the earthquakes. The pre-existing fault which was triggered into action by Cuadrilla’s fracking has not (even today) been definitively identified. It was therefore reckless for Cuadrilla to continue not only with a deformed well casing but without performing further geological investigation.

Cuadrilla’s management was criticised by government in December 2012, and Ed Davey promised an independent review into Cuadrilla's competence. Despite repeated requests his department DECC has refused to come up with a copy of that report. It is suspected that Lord Browne - who has a central role in government despite having a tarnished reputation in business, where he was widely accused of loosening safety standards in BP, and in the British High Court, where he was found to be a serial liar - had a hand in minimising the damage to Cuadrilla, in which company he has a large personal stake.

So that is old news, what of more recent activity?

This year Cuadrilla applied for and were granted an extended period on their "temporary" permission, to abandon the well and restore the well site. This is the THIRD such extension they have been granted. An exploration which should have lasted 18 months has now been allowed to run for SIX years.

However, earlier this year it emerged that a new problem had occurred with PH1. The well experienced annular pressure problems indicating a well barrier failure. This was not a new experience for Cuadrilla. At Anna's Road in the Fylde there were doubts expressed about the well's cement casing. This, and the loss of a tool - known as a packer - down the hole resulted in Cuadrilla being forced to abandon that well.

But at Preese Hall it transpired that the new failure was unassociated with the original deformation caused by the earthquake. Two problems in the same well is two too many. Problems in two different wells is a sad reflection on Cuadrilla's capability.

The Health and Safety Executive claim through Freedom of Informnation request that there was no leak to the atmosphere. As they themselves performed no checks it is not clear how they can be sure of that. They have not confirmed there was no leak to the geological formations outside the well. They suggest that the casing was thick enough to prevent "significant" leaks to the surface or the overlying saline aquifer. Again, as always with HSE, this guess can only be as a result of a desk check of information provided by Cuadrilla. In any event, they did not themselves inspect the well. What they have confirmed is that it was necessary to agree remedial action for the well with Cuadrilla, before it could be abandoned. But they have made no inspection to ensure that such remedial action has been completed as per the agreement. DECC, who were said to be responsible for agreeing abandonment procedures, have failed to provide any information on what agreement has been made with Cuadrilla for the abandonment process. What is sure is that there are no guarantees in place to cover any future leakage or similar incident caused by further well breakdown.

HSE have also confirmed they will not be performing any monitoring post well abandonment.

Cuadrilla applied for and obtained this month yet another extension from Lancashire County Council for abandonment and restoration of the site, but have failed to provide either LCC or Fylde Borough Council with full information on the problems they have experienced at Preese Hall. All such information had to be provided by individuals and organisation who had prised limited information out of DECC or HSE.

This whole story exemplifies how inadequate regulation of onshore shale gas fracking is, and how incompetent Cuadrilla are as novice operators. The scandal is that we may never know whether there has been a cover up of whether PH1 was actually leaking at any time, and - more importantly - whether it will leave a leaky legacy continuing into the future.

Another question - If there was no leak and no prospect of a leak, why were Cuadrilla driven into an agreement with LCC to perform water monitoring nearby for a (pathetically short) period of only one year?

Another question. Why did LCC not discuss this in their planning meeting to extend the PH1 permission? Why did they totally ignore debating whether a long-term monitoring of PH1, its integrity, its potential leaks to ground water or air, when they now knew there had been a problem? It is not only the regulatory system and the regulators who will not protect us. We can not expect protection either from the County Council. They are simply not competent to make decisions on shale gas. The councillors rel;y on officers who are not conversant with onshore shale gas operations. NOBODY IS. This is why councillors should say NO to an experiment on the Fylde. Our environment and our health are at stake.

"There was pressure on the B annulus – between the 5 1/2” and 9 5/8” casings. The 9 5/8” casing was cemented to inside the 13 3/8” casing to 1290ft and the 13 3/8” was cemented to surface. This was not associated with the previously deformed casing.
HSE, FOI response 30Sept2014

"Given the number of wells that would have to be drilled in the UK to satisfy the frackers’ demand for gas output, even a one in a thousand chance of well failure would probably mean a disaster for the Fylde. But if in reality the figures were put at only one in fifty, that’s maybe 80 wells failing. Remembering that an abandoned well is capable of leaking methane forever, not just for the lifetime of the well’s production, then if we believe that all wells will fail in time we are looking at not just a risky plan for converting Britain’s countryside to gas production, but an insane one. In a hundred years four thousand wells leaking methane and other contaminants up to the surface, and through drinking water aquifers, is not an attractive future, to say the least."
Fracking The UK

"Worldwide the industry does not have a good record when it comes to well integrity. One in fifty failures would be extremely optimistic and far away from the scary reality.
Cornell University engineer Anthony Ingraffea, who has been outspoken in blowing the whistle on oil and gas industry practice is rapidly becoming a bęte noir of the frackers.
He claims that industry studies show that 5 to 7% of all new wells leak. As they age, the figure can rise to between 30 and 50%. Horizontally fracked wells have the worst record.
Offshore oil wells in the Gulf of Mexico report leakage rates of some 60% after 16 years of service. In the North Sea the Norwegian Petroleum Safety Authority reports that 18% of deep offshore oil and gas wells have integrity problems. Australia has chronic leakage problems from fractured coal bed methane (CBM) wells. In Canada, according to industry returns to regulators, about 5% of 300,000 oil and gas wells are leaking. That’s 15,000 leaking. But an independent study by Bachu and Watson estimated the percentage for the deviated (i.e. non-vertical) wells rose to perhaps 60%.
Given the risk that high-pressure fracking increases the chance of leaks creating pathways percolating to other wells, the atmosphere and groundwater, these are not encouraging statistics.

Even worse is the conclusion reached by several commentators that all wells will fail in time.
Fracking The UK

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