oa Tanjung Jabung Seismic Project: Key Challenges and Issues in Managing Four Different Seismic Methods in One Project

Tanjung Jabung Block seismic project, conducted onshore and offshore of Indonesian Province of Iambi, was one of the challenging seismic survey operations undertaken by Petronas Carigali. Four types of seismic methods, i.e. shallow marine streamer, land, ocean bottom cable dual component (OBC-2C) and transition zone (TZ), were deployed successively. As there were no technically qualified contractors capable of providing services for all four methods, Petronas Carigali decided to split the works into two different seismic survey contractors. While the decision to deploy multi seismic methods was a cost-effective one, it added significant technical, operation and HSE challenges. This paper describes several key challenges, issues and adopted solutions during all the above four different seismic survey methods. As TZ and OBC-2C methods utilized different types of sources and receivers, optimum data overlap was essential for the design of seismic data processing matching filter to correctly merge these two different data types. However, it was challenging task to correctly acquire this required overlap due to shallow water, high daily tide and contractor’s equipment. Harsh working conditions, private cultivated lands, busy shipping lanes, intensive fishing activities, under adaptation of locally sourced boats and lack of contractor’s advance computer QC software were few examples of project key challenges and issues. There were also environmental related challenges and issues where the local authorities prohibited any seismic survey works within the mangrove nature reserve causing no seismic data zone between land and TZ surveys. This no data zone is a challenge for our geophysicist to accurately tie seismic data between land and offshore areas. Additionally there were contract administration and procurement related challenges and issues. It was challenging task to timely administer contracts as there were seven different contracts of various specifications with several contractors. Close onsite project supervision, excellent communication among all parties, thorough project work planning and close interactions with contractor during the operations are several lessons learnt from this project. At the end, the project was successfully completed without any LTI incidents after more than 1.3 millions man-hours were recorded.