WoldWide Drilling Resource

Directional Drilling Site in UK Releases Environmental Data Adapted from Information by Cuadrilla Resources Ltd In the UK, shale gas exploration company Cuadrilla Resources Ltd is making use of its website, or ePortal, to share envi- ron mental data fro m its Preston New Road (PNR) drilling project, near Blackpool, Lancashire. Cuadrilla’s ePortal, featured in the August 2018 issue of WWDR , allows members of the public to track the status of environmental monitoring. The data includes hundreds of thousands of separate air quality readings taken continuously for more than a year. A baseline was established using data collected during monitoring of the area between February 2016 and January 2018. The British Geological Survey (BGS) observed baseline levels, before site construction, and recorded ambient methane levels of up to 70 ppm (parts per million). Since the beginning of 2018, a group of independent specialists have conducted continuous air monitoring, including recording methane and nitrogen dioxide levels. As part of the project’s environmental permit conditions, methane levels above 7.1 ppm must be relayed to the Environment Agency (EA). There are hundreds of thousands of readings from each stage of the process including the drilling of two wells and hydraulic fracturing operations. Monitoring between mid-October and mid-December 2018, indicated the following results: j There have been four separate instances of elevated methane levels recorded since May 2018, when a continuous methane detector was installed. Periods of elevated readings were less than 0.3% of the time, and the EA was notified of each occurrence. j 99.7% of the time, methane levels in and around the site were below the 7.1 ppm standard. This included operational activities and during hydraulic fracturing and flaring. j Three of the methane spikes were recorded in January 2019. The highest was due to a controlled release of methane through the flare during the well testing phase; it spiked at 30.5 ppm, which is still less than half of the highest level recorded during the baseline period. j Methane was mixed with nitrogen gas for a short time which formed a noncombustible mix in the on-site flare. The flare pilot light was ignited to try and combust the mixture, and propane was also added for the same purpose, but the methane and nitrogen gas mixture could not be burned. j The fourth instance of elevated methane emissions was in October 2018, when a reading of 12.1 ppm was recorded for about ten minutes. This was due to methane gas in the flow- back water stored in tanks. The continuous monitoring site is only part of the monitoring network at PNR. The Lancashire County Council described the network as, “highly detailed and professional monitoring” which has made this the most monitored site in Europe. Nick Mace, environmental manager at Cuadrilla said, “We are very proud of the extensive monitoring program . . . It has worked exceptionally well and the data set is probably the most compre- hensive ever gathered at a shale gas exploration site. It shows how seriously we take our environmental responsibili- ties at Cuadrilla. The absolute level of methane emissions over the 12-month reporting period is reassuringly tiny. Whi le there were four instances of somewhat higher methane levels detected at Preston New Road, let me put these into context to reassure peo- ple. The instances were short in duration, very low in absolute volume, and natu- rally-occurring background methane at this level was also detected before the site existed, so it is not uncommon to see short-term spikes in data. In addi- tion, there are no health consequences whatsoever from very short-term emis- sions of methane at these low concen- trations.” DIR 45 WorldWide Drilling Resource ® JULY 2019