JOHOR BAHARU (Nov 12): The large-scale Tapis enhanced oil recovery (EOR) project is a major milestone for Malaysia's oil and gas upstream industry.

The project, one of the  largest water-alternating gas (WAG) projects of its kind to be implemented offshore in Southeast Asia, is a move by ExxonMobil Exploration and Production Malaysia Inc (EMEPMI) together with joint venture partner PETRONAS Carigali Sdn Bhd and national oil company Petroliam Nasional Bhd (PETRONAS) to rejuvenate the mature Tapis oilfield located 200 km offshore
Peninsular Malaysia.

Since the start of production in 1978, the Tapis field has produced approximately 400 million barrels of oil, peaking at about 80,000 barrels per day in the 1980s and down to just between 4,000 and 6,000 barrels per day currently.

The implementation of EOR technology using WAG measure will boost output to up to 35,000 barrels oil per day at its peak, expected in 2016 and 2017, and inject new life into the maturing oil field. With the introduction of EOR, the lifespan of the Tapis field will be prolonged by at least 20 to 30 more years.

EMEPMI Chairman/President, J. Hunter Farris, said the significant investment in the field, totalling RM10 billion, will bring new life to the asset, which in turn will provide continued oil supply and revenue to Malaysia.

"The Tapis field is currently at the end of its water flooding cycle. EOR allows us to continue production of remaining unswept oil that has been left behind through the current water flooding recovery techniques.

"The first EOR production is scheduled in 2014.Though EOR cannot bring production to the high levels achieved during its
peak production period, the technology is able to offset production decline and bring in new production that would otherwise be unrecoverable without the use of the EOR technology," he told a media conference recently.

He was speaking after the recent Tapis-R topsides onshore fabrication celebration at the Malaysia Marine and Heavy Engineering Bhd fabrication yard.

PETRONAS Vice President (Petroleum Management Unit), Ramlan Abdul Malek, said the company, based on its screening study, has identified 14 fields where EOR could be implemented in the future.

Of the 14 fields, he said, five are in Sarawak, four in Sabah, and the rest offshore Peninsular Malaysia.

"Among the identified fields, Tapis is the first for WAG technology to be implemented. For the other fields, we will progressively implement in due course," he said.

He said the company is also researching other methods to prolong the life of an oilfield after the EOR period was completed.

PETRONAS Head of EOR Programme, Exploration and Production Technology Division, Dr Nasir Darman, said the company targets to recover 750 million barrels to one billion barrels from the 14 identified wells.

EOR technology uses gas, chemical injection or thermal flooding to improve oil recovery from the industry norms of 20-35 per cent to 30-50 per cent, extracting the maximum potential from mature oil fields.

A variety of EOR methods -- such as WAG, chemical and microbial -– are developed and applied to mature and mostly depleted oil reservoirs to improve the efficiency of oil recovery compared with primary (pressure depletion) and secondary (water flooding) oil methods.