BP taps cutting-edge 4D seismic tech to survey Azerbaijani oil field

Faced with declining production from Azerbaijan's main Azeri-Chirag-Guneshli (ACG) oil field, field operator BP has launched what it says is "globally" its biggest-ever seismic survey program aimed at maximizing output.

Launched on January 23rd, the new survey will cost $370 million over five years and will cover an area of 740 square kilometers, focusing on the Balakhany and Fasila oil reservoirs, the two main reservoirs in the ACG field, Eurasianet reports. 

The survey itself will be conducted by sub-contractor Caspian Geo LLC using two specialized vessels, the Murovdag and the Guba using a survey technique called 4D seismic surveying.

Seismic surveying is a technique that uses controlled explosions on the seabed to send seismic waves through kilometers of rock below.

The reflections of these waves are detected and the data are recorded and analyzed to produce a three-dimensional (3D) picture of the oil reservoirs. 

A "4D" or four-dimensional survey is the same 3D survey but conducted at the same points over an extended period of time and will show how the volume of oil in different parts of the reservoirs is changing and how much oil remains there.

"By committing to this wide-scale seismic acquisition we aim to obtain comprehensive understanding of the reservoir’s architecture," said BP's vice president for subsurface operations in the Azerbaijan, Georgia and Turkey region, Roshni Moosai.

"We hope the most up-to-date 4D technology to be used for this program will allow us to acquire further in-depth data about the reservoir helping us identify ways to minimize future well surprises and maximize the field recovery in the next decades," she added.

Generally, seismic surveys are used to try to identify new oil and gas reserves although in this case BP has confirmed that the aim is only to help better understand the existing reserves and not to identify new ones. 

Declining production

Production from the ACG oil field began in 1997 and peaked in 2010 at around 835,000 barrels per day. 

Since then output has declined considerably, with BP's most recent results reporting that in the third quarter of last year, production averaged just 368,000 barrels per day, down 11 percent on what it was a year earlier.

The fall represents a serious drop in earnings for BP, which operates the field, and also for Azerbaijan itself, which relies on revenues from the sale of its oil and gas for over 90 percent of its revenues. 

Such a sharp decline in production is normal for an oil field that has now been producing for over 25 years. 

The ACG field also contains large volumes of natural gas, and as oil and gas are produced from the field, the pressure in the field falls, with the result that less oil and gas come up through the production wells.

Much of this gas produced is already being pumped back into the field to help force out more oil, in order to help maintain crude oil production levels. 

In addition to the new seismic survey campaign, BP is also funding other longer-term efforts to maintain or increase crude oil production from the ACG field.

In addition, this year BP will begin production from its Azeri Central East (ACE) platform, a new production rig that aims to boost output by up to 100,000 barrels per day. 

The company has not yet said exactly when production from the ACE platform 

is expected to start. Its latest statement confirmed only that it will be "early this year." 

In addition, BP announced last year that it had started drilling new wells into what it claimed were "deep" gas reservoirs beneath the ACG oil field, and Azerbaijan's main gas field, the Shah Deniz field, which it also operates. 

In July, the company confirmed that the well drilled into reserves below the ACG field had struck gas and that talks were underway with Azerbaijan's state oil company SOCAR over possible production models.

As yet no announcement has been made as to how the companies plan to proceed with this project, which, if successful, could help Azerbaijan to meet its promise made last year to Brussels, to double its exports of gas to the European Union, by 2027.