Environmental Effects Of Produced Formation Waters In The West Java Sea, Indonesia
Authors: Smith J.P. , Tyler A.O. , Rymell M.C. , Amperanto H. , Ng B. , Adisapoetra O.S. 
Published: December 2007

J.P. Smith, SPE, Pertamina/Maxus SES, Inc., A.O. Tyler, BMT Marine Information System, Ltd., M.C. Rymell, BMT Marine Information System, Ltd., H. Amperanto, Pertamina/Maxus SES, Inc., B. Ng, BMT Marine Information System, Ltd., O.S. Adisapoetra, Pertamina/Maxus SES, Inc.

The most significant waste management problem of Exploration and Production operations is produced formation water. As offshore operations mature the ecotoxicological impact and long term sublethal chronic effect of discharged fluids become critical due to increasing pressure to reduce discharge pollutant concentrations discharge volumes and the ever increasing number of reviews by regulatory bodies.

The E and P industry's limited ability to respond scientifically to real and perceived problems is a result of limited research in produced water impact. In particular, a paucity of information on differing effects based on volumes, pollutant concentrations, temperature and synergy of pollutants. Most importantly, correlation of numerical modelling to discharges observed is virtually non existent.

This paper presents the results of a detailed study of the composition of produced waters and their dispersion in an offshore marine environment. Effluent waters from three outfalls situated in the West Java Sea, Indonesia were subjected to a detailed chemical analysis to determine the presence and concentration of contaminants. This information was used to target a detailed literature review to determine priority contaminants for investigation and to determine their geochemical behaviour. Combining this information with a detailed hydrodynamic model of the region around each production facility allowed simulation of the initial dilution and subsequent transport of effluent from six outfalls, each exhibiting different outfall characteristics. flow rates, discharge depths and contaminant concentrations. The modelling was calibrated using results from dye tracing experiments conducted at one of the facilities. Once calibrated, the model has been run for a range of metocean scenarios representing the changes in environmental conditions with tidal states and monsoon season thus allowing the environmental impact of the effluent stream to be assessed.

Introduction

Pertamina/Maxus Operation Area. Pertamina/Maxus operations are located within the mining contract zone (WKP) designated as Southeast Sumatra. All Pertamina/Maxus SES facilities are offshore on the Java Sea side of the Sunda Straits north of the island of Java and southeast of the island of Sumatra or loosely situated between 4 30' and 6 South of the equator (Fig. 1). The contract area covers 11,000 square kilometers and adjoins to the Pulau Seribu, a resort area and a marine park.

Currently, Pertamina/Maxus operates sixty-three platforms of which fifty-four are unmanned. Accommodation for seven hundred and eighty offshore employees and contractors are located at Pabelokan Island, two floating storage facilities, and the accommodation barge, Duta-I. The produced fluids originate from the fifty-three unmanned platforms which are interconnected to three process platforms. The processed hydrocarbons are forwarded by subsea lines, Single Bouy Mooring (SBM). and floating hose to the floating storage facilities at Cinta Natomas and Pertamina/Maxus Widuri.

West Java Sea Environment The environment of the West Java Sea has a rich diversity of marine life. Off the North coast of Java Island lies the Pulau Seribu (Thousand Islands) archipelago made up of approximately 106 islands surrounded by extensive coral reefs and lagoons.

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