Environmentally friendly drilling

Brian Stringer
National Secretary at British Drilling Association
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Post date: Wednesday, 24th August 2011

One of the headlines that followed the 2010 Gulf of Mexico oil spill, which released 4.9 million barrels of crude oil into offshore waters, was: “Drilling is killing the environment”. During April and May 2011, two earthquakes of 2.3 and 1.5 magnitude hit near Blackpool in UK and the headline was: “Blackpool tremors may have been caused by gas drilling”. In southern Germany, parts of the small town of Staufen have risen 30cm since 2008, causing structural damage – the headline here is: “After geothermal drilling, a town rips up”.

While these examples are extreme, they illustrate the law of unintended consequences – actions always have effects that are unanticipated or unintended.

Drilling’s effect doesn’t have to be as severe as potentially polluting miles of coastlines or causing underground disturbances for us to be concerned for the environment. In everyday activity, there is much that can be done to anticipate harm to the environment and thereby prevent or minimise it happening. Legislation helps us indirectly, in that it places responsibilities on us to protect the environment; gives examples of what we shouldn’t be doing, and provides penalties for those who transgress. In the UK, the Environmental Protection Act, the Environment Act and many other Acts and regulations provide this legislative framework. The government’s Environment Agency is the regulator and a source of much guidance.

There is an overlap between environmental and health legislation. Take noise pollution for example, which is not only bad for the general environment (public, animals, wildlife etc.) but also is the subject of worker protection through the Noise at Work Regulations. It is sometimes not clear that when we talk about environmental damage, we are in fact talking, in the majority of cases, about what hurts people. Tree hugging and saving the planet get all the headlines, but ultimately it comes down to the effects on you and I.

Are there any benefits other than avoiding prosecution and paying large fines in adopting pro-environment policies? Larger companies in mining and quarrying have had no choice other than to pursue ‘green’ policies because successful planning applications and public acceptance can only be achieved through exhibiting care for the environment. It is the same with the larger drilling companies. An improved image and meeting regulator/client requirements thereby produce commercial gain, i.e. more contracts. But the benefits exceed this. For example, low particulate exhaust emissions are provided by fuel-efficient engines, i.e. savings on fuel bills.

How can we carry out drilling in a more environmentally friendly way? What practical things can we do that we may not be doing already? Very few people can be motivated purely by appealing to their environmental conscience. Business is business and has to make commercial sense; taking on further cost without increased revenue/profit planning is a road to ruin.

Drilling utilises plant whose prime energy source for surface drilling is diesel engines. Reduction of carbon output and particulate emission should be an environmental goal. Switching to more modern plant can achieve this goal. In turn, the new plant will be more fuel efficient and more productive (for example, automatic rod handling for new drill rigs). Investment in new plant satisfies environmental issues; produces fuel savings; gives productivity gains; raises worker respect and loyalty for the company; produces a better image, and less plant maintenance.

What about the drilling method? Client specification can be negotiated if an alternative will produce the same required product results. For example the client may specify an NQ (wireline hole size 75.7mm) size core of 47.6mm. A core size of 45.2mm (a little bit less) can be obtained from a hole size of 56.3mm using a TT56 core barrel, requiring much less rock to cut, with consequent energy savings and faster penetration. Other factors may still determine that wireline is the correct choice (such as depth, tripping times, bit life, ground conditions etc.) but conventional thin-walled core barrels should very often be considered, if only from an environmental viewpoint. Consider, for example, that an NQ impregnated core bit has more carats of synthetic diamond than TT56. What’s the energy requirement per carat to produce synthetic diamond?

Drilling in all its forms can be more environmentally friendly. Biodegradable drilling fluids can be utilised. Air flush drilling, which is compressor dependent, is more energy intensive than water flush, although the right choice on many occasions. Disposal of drilling cuttings either to atmosphere (air borne dust) or runoff cannot be acceptable. Leaving pathways through inadequately sealed boreholes for surface or underground contamination to reach groundwater is not protecting the environment. Encountering hazardous gases during drilling may be a real risk to drilling personnel, however, could our drilling process (mainly air flush) be creating and/or driving hazardous gases through the ground for emergence elsewhere, where it is harmful to other people?

Perhaps more questions than answers. The drilling industry is no more immune to environmental considerations than any other sector. As such it’s engaged in examining its environmental credentials; seeking improvement; discussing with clients, and ensuring that it plays its part in protecting the environment and peoples’ health.

This article first appeared in Quarries and Mines 2012. To read the entire publication, click the ebook.

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