Lengo gas field is located within the Bulu PSC in the East Java Sea, Indonesia, at water depths ranging between 50m and 60m. The field’s plan of development (POD) was submitted to the Indonesian Government in July 2014 and was approved in December 2014.
The Bulu PSC covers an area of approximately 697km² integrating three separate areas, namely Bulu A, Bulu B and Bulu C. The Lengo gas discovery is located within the Bulu A area.
KrisEnergy operates the field, holding a 42.5% working interest in the Bulu PSC along with its joint venture (JV) partners AWE (42.5%), PT Satria Energindo (10%) and PT Satria Wijayakusuma (5%).
The front-end engineering design (FEED) study for the project is being performed, while the company is yet to make a final investment decision. Production is expected to begin after two years of construction activities, with peak production expected to reach 70 million metric standard cubic feet a day (MMscfd).
Lengo gas field discovery and appraisal
The Lengo field was discovered in 2008 by drilling the Lengo-1 exploration well. Drilled to a total depth of 959m (3,146ft), the exploratory well flowed at a rate of 12.8Mmscfd during the production test and penetrated a 142ft gas column.
The field was further appraised by drilling the Lengo-2 appraisal well in April and May 2013. The vertical well was drilled at a water depth of 57m and to a total depth of 837.6m (2,748ft), deploying Shelf Drilling’s Randolph Yost jack-up rig. Two separate drill stem tests (DST) were performed on the well achieved maximum gas flow rates of 4.5MMscfd and 21.2MMscfd respectively.
Lengo gas field reserves and geology
The offshore gas field is estimated to hold 200 billion cubic feet (bcf) of recoverable sales gas in reservoirs located within the Miocene Kujung 1 formation.
Lengo gas field development details
The conceptual plan for the field development involves the drilling of four production wells, and the installation of an unmanned wellhead platform (WHP) and a 65km-long and 20in-diameter export pipeline to transport the gas to an onshore gas receiving facility.
The infrastructure is expected to serve as a hub for other gas fields located offshore East Java. The Lengo East discovery located in the adjacent East Muriah PSC is expected to be developed as a single well tied-back to the Lengo field, while the production from the neighbouring Sakti PSC, where a 1,202km 2D and 401km² 3D seismic data were acquired in early 2015, is also expected to be hosted.
Gas sales agreement
A memorandum of understanding (MoU) was signed with a potential off-taker in mid-2014. As of July 2015, gas sales agreements are in progress with more parties.
Contractors involved with the Indonesian offshore field
Java Offshore started the geophysical and geotechnical surveys for the proposed platform site, platform-to-shore pipeline route and onshore receiving terminal location in April 2014 and completed them in mid-2015. The FEED study for the Lengo field is being performed by PT Synergy Engineering.