All production of hydrocarbons in Denmark currently takes place offshore, and the actual production and drilling of wells result in discharges into the marine environ-ment. It is also offshore that most exploration activities, including the acquisition
of seismic data, have taken place. As a result, marine flora and fauna are exposed to impacts. In partnership with many other authorities and organizations, the DEA is responsible for protecting the marine environment.
Marine discharges
Chemicals, oil residue and subsoil material are discharged into the sea in connection with oil and gas production and the drilling of new wells. In addition, unintentional oil spills may occur.
To reduce the environmental impact from the discharge of chemical residue, environ-mentally hazardous chemicals are substituted by less hazardous ones where possible.
Attempts are also made to reduce the discharge of oil residue.
Regulation of discharges
Marine discharges are regulated by the Marine Environment Protection Act and the Mini ster for the Environment’s Offshore Action Plan, which sets targets for the dis-charge of oil in produced water and chemicals as well as atmospheric pollution. Through agreements under the international OSPAR Convention on the Protection of the Marine Environment (see box 5.2), Denmark has committed itself to regulating discharges in the same way as the other Contracting Parties. The objective of the OSPAR Convention is to protect the marine environment of the North-East Atlantic, including the North Sea.
Under the OSPAR Convention’s requirements concerning the discharge of produced water, the concentration of dispersed oil has not been permitted to exceed 30 mg/l since 2006. In the discharged produced water from the Danish fields, the average con-centration today is considerably lower. The negotiations that are under way between the OSPAR member countries are moving towards a risk-based approach for the determination of restrictions on discharges.
In 2001, the OSPAR member countries adopted a recommendation to reduce total discharged oil by 15 per cent, compared to the equivalent discharge in the year 2000, during the period until 2006.
To achieve this goal, the Minister for the Environment launched the Offshore Action Plan in 2005, followed by a revised plan for the period 2008-2010. In this connection, investigations were commenced to assess the potential for further reductions in the discharge of oil with produced water. This work was continued during 2009 with a study looking at the opportunities for increasing the reinjection of produced water to replace treated seawater as a source of pressure support for production.
One of the challenges associated with reinjecting produced water into the chalk reser-voirs that make up the majority of Danish oil fields is to achieve adequate water treat-ment in order to avoid a reduction in the reservoir’s performance and increased wear on equipment. Tests are planned to determine whether the reinjection of produced water could replace treated seawater as a source of pressure support for production.
The Danish Environmental Protection Agency regularly supervises the operators’
compliance with the Offshore Action Plan and submits an annual status report to the Danish Parliament. Moreover, the Danish operators (DONG E&P A/S, Hess Denmark ApS and Mærsk Olie og Gas AS) prepare a publicly accessible report every year that accounts for the environmental impacts associated with oil and gas production in the Danish sector of the North Sea.
Box 5.2
OSPAR
The Oslo-Paris Convention (OSPAR) for the Protection of the Marine Environment covers the North-East Atlantic and comprises 15 countries, including Denmark.
In the oil and gas area, the DEA assists the Danish Environmental Protection Agency with technical expertise related to the work under OSPAR for the protection of the marine environment, e.g., in the North Sea. The detailed con-tent and scope of the Convention can be read on OSPAR’s website, www.ospar.org.
The work concerning the oil and gas industry is primarily carried out in a committee called the Offshore Industry Committee (OIC), which works on an ongoing basis and meets annually.
Noise from seismic surveys
Another environmental impact of oil and gas operations is noise from the acquisition of seismic data. During seismic surveys, a sound source sends out pressure waves, which are reflected by the layers in the subsoil; see box 1.4 in chapter 1, Licences and exploration. This noise can disturb marine mammals such as the porpoise, a species of whale that is protected by the EU Habitats Directive. The Habitats Directive imposes strict measures for the protection of all species of whale and dolphin. In Denmark, porpoises are found in the inner Danish waters and in the North Sea, where most of the Danish oil and gas operations take place. The DEA has therefore introduced a series of conditions for the acquisition of seismic data.
The DEA must approve all seismic surveys before the work is commenced. When a com-pany wishes to acquire seismic data in an area, the comcom-pany must submit an application to the DEA. Before the company is permitted to carry out the seismic survey, the DEA will in each individual case review the information in the application concerning equipment, programme and method of execution. The DEA will also specifically assess the possible adverse impacts on animal life in the affected areas, including whether the seismic survey would be carried out in accordance with the provisions of the EU Habitats Directive.
To ensure that the seismic surveys are carried out in accordance with the Habitats Directive, the DEA will make the approval conditional on the company implementing preventive measures to give the marine mammals sufficient time to leave the area before the seismic activities are initiated.
One standard condition is that companies must use what is known as a “soft start procedure” when the seismic survey is carried out. The soft start procedure is based on slowly increasing the sound level from the seismic air gun up to the operational level. If marine mammals are observed at a distance of less than 200 metres from the sound source, the soft start procedure must be postponed. The soft start procedure must be carried out in accordance with a set of “best practice” guidelines, prepared by the National Environmental Research Institute (NERI) at Aarhus University.
In rare cases, explosives will be used as a sound source instead of an air gun. In such cases, corresponding conditions are imposed which require small warning detonations within a 20-30 minute period before the survey detonation itself. When dynamite is used, it is a condition that the company checks the area for marine mammals before carrying out the seismic detonations. If there are marine mammals in the area, the detonations must be postponed.
The conditions that are imposed in connection with the approval of seismic surveys at sea are partly based on the latest data and information concerning the presence and behaviour of the marine mammals that live in the Danish offshore area. The DEA con-tinually reassesses and updates the conditions as new knowledge about the subject is acquired, e.g. via conditions in licences, in order to ensure compliance with the require-ments of the Habitats Directive concerning the strict protection of whales and dolphins.
At the end of 2009, the DEA received preliminary reports concerning the provisional results from two monitoring programmes relating to, e.g., the behaviour and distribu-tion of porpoise in the western area of the North Sea from Mærsk Olie og Gas AS.
Mærsk Olie og Gas AS has monitoring programmes carried out as part of the com-pany’s obligations in connection with oil and gas operations. Based on the results in the reports, the DEA has instigated work to clarify whether further initiatives will
be required to ensure the best protection of porpoises and dolphins. The DEA has therefore consulted DMU and the Agency for Spatial and Environmental Planning and is awaiting DMU’s assessment of the results from the two reports. The reassessment of the conditions is expected to be completed during the summer of 2010.
When this report went to press, the ongoing reassessment of the conditions imposed for the approval of offshore seismic surveys had not been completed. When the reassess-ment has been completed, the results will be placed on the DEA’s website, www.ens.dk.
Conditions requiring the use of soft start procedures, etc. are also imposed in con-nection with other noise-generating activities such as piling works in the seabed.
Piling works are for example carried out in connection with the installation of piles to anchor platforms and during the drilling of wells, where conductors protecting the upper section of a well are driven into the seabed.
The Marine Strategy Framework Directive
The Marine Strategy Framework Directive is intended to establish a framework for the EU’s marine environment policy measures. Via the Marine Strategy Framework Directive, a common timetable has been agreed at EU level to ensure good environmental status in marine areas by 2020. The Marine Strategy Framework Directive must be implemented into Danish legislation by 15 July 2010. For this purpose, the Minister for the Environment presented a Marine Strategy Bill in the Danish Parliament on 21 January 2010.
In this connection, the DEA has taken part in analyses concerning possible conse-quences of implementing the Marine Strategy Framework Directive in Denmark. These analyses have been carried out by the Agency for Spatial and Environmental Planning.
Integrated maritime policy
The “Maritime Blue Book” on an integrated EU maritime policy was adopted by the European Commission in October 2007 and subsequently approved by the Council of Europe. In June 2008, the Commission subsequently issued guidelines for an integrated approach to maritime policy.
The preparation of a Danish integrated maritime policy was begun in 2009 as a project under the Danish Maritime Authority. The aim is to draw up a Danish integrated maritime policy, which can form the basis for growth-oriented and environmentally and climatically sustainable commercial development for the maritime sectors. The intention is not to replace, but to supplement, the sector-based policies. The project will seek to link together the many considerations in the maritime area, create a series of concrete initiatives and promote coordination between authorities with tasks within the maritime area. The maritime sectors in a broad sense also include offshore energy production. Against this background, the DEA has participated in the project and contributed with regard to oil and gas production offshore and offshore wind tur-bines. The Ministry of Economic and Business Affairs expects the integrated maritime policy, which will set out the Government’s policies in the area, to be issued in 2010.