This joint report details the existing regulations and guidelines relating to well integrity on the UK mainland for oil and gas exploration and production, including shale gas.
The report aims to inform the general public about onshore well integrity and to give an informed view of current practices.
What is Well Integrity?
Oil & Gas UK defines well integrity as “the application of technical, operational and organisational solutions to reduce the risk of uncontrolled release of formation fluids throughout the life cycle of the well”.
Following the discovery of substantial gas reserves in the North Sea in the early 1960’s the United Kingdom moved from coal to gas as the fuel of choice for power generation and domestic heating/cooking. This trend was accelerated in recent years in an effort to reduce carbon dioxide emissions, with gas being viewed as a cleaner fuel than coal.
Domestic gas production from the UK Continental Shelf (UKCS) is insufficient to meet UK demand, currently supplying around 48% of demand. The UK is therefore reliant on importing gas to meet the majority of the demand. Approximately 38% of UK gas is supplied through pipelines from continental Europe and Scandinavia. With the remaining 14% of demand being met by Liquefied Natural Gas (LNG) supplied by ships, primarily from the Middle East. Imported gas is less secure than domestic gas, has commercial risks associated with currency exchange rates, has a negative impact on the UK balance of payments and does not contribute the revenue associated with gas production into the UK economy.
The United States has led the large-scale development of shale oil and gas using high volume hydraulic fracturing. This has been transformational for the US economy, by increasing the availability and reducing the cost of this energy source. But they have a different land-ownership regime. The UK has extensive onshore shale gas and oil resources located in central Scotland and England.
The UK government has issued licences to enable companies to undertake exploration work to determine if UK shale gas and oil can be economically developed. The first dedicated shale gas well was drilled at Preese Hall in Lancashire in 2010. During the initial stages of high volume fracturing of the well low level earth tremors were recorded and the operation was shut down. There was significant media interest and the UK government imposed a moratorium on further activity. The moratorium was lifted following evaluation and agreement on guidelines for future activity.
Proposed onshore UK shale gas and oil exploration has continued to attract significant attention from the media, politicians, environmental groups, protest groups, business groups and the public at large. Local councilors turned down an application for further shale gas exploration activity in Lancashire and there is significant resistance to an application for fracking in North Yorkshire.
The information often used to oppose shale gas extraction through hydraulic fracturing often includes experience from the US, which is not in line with the UK regulatory framework.
There has been opposition to extraction of natural gas through hydraulic fracturing and much information has been made public that supports opponent’s viewpoints; this has often included experience from the US, which is not relevant to the UK. One of the key topics of discussion has been well integrity.
The Institution of Mechanical Engineers and the Institute of Materials, Minerals and Mining collaborated to form a joint work group to provide the public with an engineering view on well integrity pertaining to UK onshore shale gas wells to assist the public to have an informed view.
This report reviews the regulatory framework and activities surrounding onshore UK well integrity, as this covers most areas of concern.
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Download the UK Onshore Well Integrity report.