Environmental performance: six ways IOGP is increasing transparency

With the latest edition of the environmental performance indicators series just published, IOGP has provided the public with the most up-to-date global information on the performance of IOGP member companies, broken down into six categories.

Published annually since 1999, this series outlines the environmental performance of the contributing member companies. This year’s report focuses on 2013 data from 43 companies – 3 reporting for the first time. The data represent 2,077 million tonnes of hydrocarbon production, approximately equivalent to 29% of world production in 2013.

IOGP categorizes this environmental performance data in six ways:

1. Gaseous emissions

The report includes the gaseous emissions that are considered the most relevant from process control as well as regulatory perspectives:

In 2013, upstream emissions from reporting were:

• 259 million tonnes of carbon dioxide (CO₂)
• 1.9 million tonnes of methane (CH₄)
• 921 thousand tonnes of non-methane volatile organic compounds (NMVOC)
• 400 thousand tonnes of sulphur dioxide (SO₂)
• 801 thousand tonnes of nitrogen oxides (NO_X)

When compared with 2012* data, per unit of production figures show:

• CH₄ emissions decreased by 27%
• SO₂ emissions increased by 24%
• NO_X emissions decreased by 7%
• CO₂ emissions decreased by 4%
• NMVOC emissions increased by 2%

* including the effects introduced by changes in the companies reporting

2. Energy consumption

It takes significant amount of energy to extract, process and transport oil and gas.  In many oilfields, locally produced gas meets those energy needs.

In 2013, IOGP reporting companies consumed on average 1.5 gigaJoules of energy for every tonne of hydrocarbon produced; a 4% increase compared with the 2012 average.

As in previous years, data indicate that onshore production in 2013 was more energy intensive than offshore production.

3. Flaring

Flaring is the controlled burning of hydrocarbons produced in the course of petroleum exploration and production operations. It includes the controlled and safe burning of gas that, for safety or technical reasons or for lack of export infrastructure, is not used or exported.

In 2013, reporting companies flared 15.1 tonnes of gas for every thousand tonnes of hydrocarbon produced, versus 13.9 tonnes in 2012 and 15.7 in 2011.

4. Aqueous discharges

Produced water – the water that comes to the surface with oil and gas – is the highest volume liquid discharge generated during the production process. It consists of formation water (water present naturally in the reservoir), floodwater (water previously injected into the reservoir) and/or condensed water (in the case of some gas production).

For every tonne of hydrocarbon produced in by reporting companies in 2013 (including oil, condensates and gas), 0.6 tonne of produced water was discharged and 1.1 tonne of produced water was re-injected.

5. Non-aqueous drilling fluids retained on cuttings discharged to sea

While the oil and gas industry predominantly uses water-based drilling fluids (muds), technical challenges often require the use of non-aqueous drilling fluids (NADFs).  These provide higher lubricity, better performance at higher temperatures and greater well-bore stability compared with water-based muds.

NADFs contain more than 30% non-aqueous base fluid (NABF) as a continuous phase (typically 50%–80% by volume). The remainder consists of brine, barite and other materials such as gels and emulsifiers.

NABFs are reported according to the three classifications: diesel-based and mineral oil-based fluids (Group I fluids); low-toxicity mineral oil fluids (Group II, with reduced aromatic content); and more sophisticated drilling fluids (Group III, with low to negligible aromatic content).

Group III fluids deliver high drilling performance while ensuring that any discharges of drilling fluids adhering to cuttings or discharges of whole mud pose minimal threat to the marine environment.

The 2013 data shows that reporting companies discharged 15,347 tonnes of non-aqueous base fluids (NABF) on drill cuttings to sea. Of these discharge fluids, 96% were in Group III and 4% were in Group II.

No company has registered discharges of Group I fluids retained on cuttings since the reporting of NABF by Group I, II and III classification began in 2003.

6. Spills of oil and chemicals

Spills are an important environmental performance indicator for the oil and gas industry, since they can have a significant and visible impact on the environment. In this report, a spill is defined as any loss of containment that reaches the environment irrespective of quantity recovered.

In 2013, companies reported 2,270 oil spills of greater than one barrel in size – a normalized spill rate of 1.2 oil spills per million tonnes of hydrocarbon production.

These spills resulted in the release of a total of 7,585 tonnes of oil. In 2013, the quantity of oil spilled per unit of hydrocarbon production had fallen to a rate of 4.1 tonnes per million tonnes production, 13% lower than 2012 rate and 48% lower than the rate for 2011.

Report 2013e, Environmental performance indicators – 2013 data is available to download here.