ADNOC looks to artificial islands, EOR to boost production

Improved EOR techniques and the building of artificial islands are key elements of the strategy that the Abu Dhabi National Oil Company (ADNOC) is implementing to boost production capacity from 2.8 million bbl/day of oil with condensates now to 3.8 million bbl/day by 2020, ADNOC manager offshore division, Ali Khalifa Al Shamsi told OTC delegates in Houston on 4 May.

The artificial islands concept will play a critical role on the Upper Zakum field, the largest offshore oilfield in UAE history, currently producing 550,000 bbl/day. More than 450 total wells have been drilled on the field, over 300 of them horizontal. Five jackups are deployed on the field, along with six land-based rigs to support the FFDP (full field development plan) by extended-reach drilling (ERD) and maximum reservoir contact (MRC) wells from artificial islands, Mr Al Shamsi said.

Four such islands will be built initially – South, North, Central and West. This is a reduction from the previously planned seven, made possible with the use of ERD technologies, Mr Al Shamsi said. Additionally, MRC technology will reduce the number of wells required on each island. "We are confident that we will be able to work with our partners to turn those artificial islands into realities. The shelf life of those islands will be almost 100 years," he added. ADNOC and its partners hope to achieve a production of 750,000 bbl/day on the field by 2015.

Gas is also a key component of ADNOC's exploration program. "The UAE has the fifth-largest gas reserves (in the world). Currently Abu Dhabi depends almost totally on natural gas for power generation. Demand for electricity in the Emirates will grow by 11% (a year) through 2019 due to the expected growth in the residential and commercial projects and the industrial sectors," Mr Al Shamsi said. Meeting this demand is a major challenge for ADNOC, and "we are trying to add about 1 to 2 TCF of gas reserves annually," he continued.

This won't be an easy task, considering the high sourness of many gas reserves in the UAE. For example, on Shah, a major onshore gas field, ADNOC estimates there is about 17 TCF of gas in place, yet they'll have to contend with a high H₂S content of 23% and a CO₂ content of 10% or more in order to extract those reserves. High pressures and temperatures add another layer of difficulty, Mr Al Shamsi said.

He believes that ADNOC will have future needs in the three primary areas of EOR, sour gas development and minimizing environmental footprints. Early adoption of technology will be necessary to ensure sustainable production, and ADNOC is already taking regional initiatives in techniques like nitrogen substitution and CO₂ EOR, he said. Tight gas and unconventional resources are being evaluated as well.