Durban - American petroleum giant ExxonMobil has joined the hunt for oil and gas off the coast of South Africa, including KwaZulu-Natal, with plans to start a three-year exploration in a massive 50 000km2 search area early next year.
The exploration zone stretches from Port St Johns in the East Cape to Richards Bay in the north of KZN, at sea water depths of up to 3.6km. At its closest point, the exploration area is about 50km off the coastline, stretching almost 400km out to sea.
Several other companies have also applied for exploration permits off KZN over the past few years, including Sasol and the Singapore-based Silver Wave Energy group.
However, unlike previous and current exploration, based mainly on 2D seismic surveys, ExxonMobil is considering more sophisticated 3D and multi-beam sonar surveys, robotic submarine scanning, aircraft fly-overs, sediment core sampling and temperature measurements of the seabed.
The exploration plan follows the decision by the Petroleum Agency of SA to grant a technical co-operation permit to ExxonMobil’s South African-based subsidiary company in December 2012.
Before exploration can start, ExxonMobil has to submit an environmental management programme to the government and has set aside $10.1 million (R110m) in financial provision to manage or rehabilitate any potentially negative impacts during exploration.
A draft environmental management plan for the project suggests that ExxonMobil’s decision to explore this area indicates a strong likelihood of making further oil and gas off South Africa.
“Current interest in exploration in South Africa by experienced international exploration companies, in the face of a very competitive market for exploration acreage, indicates that the potential exists in the South African offshore for commercial oil and gas discoveries.
“This will be to the benefit of the country and its people through additional government revenues, job creation, security of the supply for South Africa’s oil and gas products, and contribution to economic growth,” says the draft report.
The Texas-based company, which was responsible for the major Exxon Valdez oil tanker pollution off the coast of Alaska in 1989, has concessions off Angola and announced several new oil and gas discoveries off Tanzania last year.
The draft environmental management programme by local consultancy firm Environmental Resources Management (which only covers the exploration phase – not drilling or pumping oil), rates the overall environmental impacts as either “low” or “negligible”.
This is despite continuing scientific controversy over the potentially harmful impacts of underwater noise on whales, fish and other sea creatures as a result of seismic and sonar surveys.
For example, the German Federal Environmental Agency placed restrictions on the use of multi-beam sonar systems in Antarctic waters in 2003 on the basis that some sound-sensitive marine creatures could suffer hearing damage or disorientation from sonar beams.
A research paper published last week on seismic surveys off the Angola coast voiced concern about possible disruption to humpback whale breeding behaviour from the intense sound pulses generated from airguns used in sonar surveys.
Another recent review of impacts from airgun seismic surveys by Dr Lindy Weilgart of the Dalhousie University in Canada concluded that human-induced noise in the sea could be detected as far as 4 000km away from the source and that at least 37 species of marine life were affected by seismic noise.
The draft environmental management plan for ExxonMobil also acknowledges that several strandings of giant squid have been associated with seismic surveys. These squid had severe internal injuries, including disintegrated muscles and unrecognisable organs, believed to be the result of rising to the surface too quickly.
The study also acknowledges that some fish showed measurable behaviour changes as far as 5km away from seismic sound blasts and reported that some whale species were likely to suffer hearing damage. As a result, the consultants have recommended that ExxonMobil used a “soft start” procedure in which the sound from seismic airguns is ramped up slowly to full volume, to allow time to fish and other creatures to flee the survey area.
The exploration could also cause disruption to deep-sea commercial fishing for tuna, swordfish and shark as the ExxonMobil seismic survey vessel would be towing a 1.2km-long array of airguns that blast sound waves of around 220 decibels to the ocean floor to build up a 2D or 3D map of the seabed.
Because the long length of these towed airguns makes it difficult for the survey vessel to manoeuvre, other vessels are required to stay at least 500m away – although the survey vessel is expected to request a much larger exclusion zone of up to 8km during the day and 12km at night
. - The Mercury