Abstract
PETRONAS is currently embarking on a project to implement Chemical Enhanced Oil Recovery (CEOR) by injecting 160,000 BWPD of chemically enhanced water consisting of Alkaline and Surfactant (AS) for a period of four (4) years. The oil field is located in the South China Sea and has been in operations for thirteen (13) years.
Initially in terms of facilities development, the base case identified for the project was a floating vessel (ship) concept which was preferred to other options considered at the time such as having a new standalone platform or a bridge link platform to house the water treatment and chemical mixing and injection facilities. Short duration of CEOR injection, opportunity to redeploy the floater to reduce lease costs as well as the ability to store large volumes of treated water and chemicals were key factors in selecting the floater to be the base case. Further studies using the floater concept i.e. Basic Engineering Design (BED) and Front End Engineering Design (FEED) were carried out in 2011 and 2012 to mature the development concept.
High project cost and chemical logistics challenges learnt from these engineering works resulted in a decision to explore other alternative facilities development concept which could meet the project requirements but at a lower cost and risks. One of the options identified is to build the CEOR Plant at onshore and deliver the chemical mixture by using a pipeline. The opportunity to consider this option was made possible with the availability of an existing oil pipeline that connects the CEOR Field and an existing Onshore Crude Oil Terminal belonging to PETRONAS. A feasibility study was immediately carried out to assess this option which included evaluation of the compatibility of the cocktail with the pipeline internal walls as well as its effectiveness after travelling the whole length of the pipeline at varying seawater temperatures. In parallel, potential locations to construct the plant were surveyed, a preliminary layout of the plant was drafted and numerous seawater intake options evaluated including the potential of using river water as alternative to seawater to produce the designer water required.
Results from the feasibility study were encouraging and high level cost estimates indicated significant savings could be achieved by pursuing the onshore plant option. More importantly logistics challenges associated with transportation of huge amount of chemicals to offshore and other operational constraints would be eliminated via this option. This new alternative concept has given a new lease of life for the project to be realized.
