According to reports and information gained under the UK Freedom of Information Act it appears that one of Cuadrilla’s initial drilling sites in the UK suffered a previously unreported structural failure.
The damage has been described by engineers as a possible “loss of wellbore integrity”, this can result in a leaking of fluid or gases from shale extraction and cause possible environmental or public health hazards.
The allegations originate from emails between Cuadrilla and the Health and Safety Executive (HSE) which suggest that the site at Preese Hall, Lancashire, suffered structural damage.
The news has caused environmental and safety concerns regarding fracking, although there is no indication that any gases escaped from the well into the air or surrounding rocks.
Cuadrilla has made no admission of such damage but Anthony Ingraffea, Professor of Engineering at Cornell University, said “it is quite apparent… that there was indeed a loss of wellbore integrity followed by attempts to remediate.”
But clarified that the blanket term covers a multitude of incidents of varying severity and as such “there are so many factors to consider” when reviewing the impact of a loss of well integrity.
The well itself was abandoned by Cuadrilla in December 2013, a HSE spokesperson asserted that “the issue has been resolved during the abandonment process” and that there had been “no leak of fluids” but that the site would be continued to be monitored for any potential concerns.
Caroline Lucas an MP for the Green Party said, “these new revelations cast serious doubt upon their [the government’s] assurances.
“Ministers claim that the serious leaks of gas and fracking fluid that have blighted the industry in the USA couldn’t happen here because of strong regulation. But now it seems that, before fracking has even started in a meaningful way… independent experts are saying that well integrity has been breached… the only safe and responsible thing to do with shale gas is to leave it in the ground.”
However, a spokesperson for Cuadrilla stated that “the well integrity at Preese Hall is secure and always has been…”
Shale Energy Insider 2014