PROCEEDINGS JOINT CONVENTION BALI 2007
The 32nd HAGI, the 36th IAGI, and The 29th IATMI Annual Convention and Exhibition
FEASIBILITY STUDY OF BIOGENIC GAS UTILITIZATION FOR COASTAL
COMMUNITY OF KAKAP AREA - KAPUAS RIVERMOUTH WEST KALIMANTAN
Hananto Kurnio1
1Marine Geology Institute
Jln. Dr. Junjunan 236, Bandung-40174, Telp:022-6032020
EXTENDED ABSTRACT
The availability of alternative energy, biogenic gas, for coastal community surrounds the existence of gas
deposit is the main objective of this study. We realized that this alternative energy availability is for noncommercial
purpose due to very limited reserve. The activities here are to help local community to fulfill
their own energy demands especially at current condition of increased oil and gas prices that mostly
unafforded by the people. Continuity of reserve availability requires continues mapping and exploration
of other gas traps in the rivermouth area of this Kapuas River.
The feasibility study for gas utilization in conformity with Marine Geological Institute tasks and duties
are directed to thorough understanding of this alternative energy which is ready to be used by the
surrounding community. The prospection includes detail mapping exploited combined methods of marine
geology and geophysics at a limited area (Prospect Area I of previous study). The combined methods are
imaging of target reservoir and conditioning of special shallow gas boring.
In China; as our reference, Biogenic Gas has been utilized for the people surround the deposits such as in
the coastal area of Yang Tze river mouth – eastern of this country. Study of biogenic gas had been
conducted in western coastal zone of Kalimantan in 2004 and 2005 and found out its potentiality. These
previous studies have delineated prospect areas.
The potential alternative energy Biogenic Gas in term of geological age is young in its formation. It
occurs in Quarternary sedimentary sequences and of shallow depths (less than 100 m below seabed). It
spread closed to large river mouths of active depositions. Large quantities of organic materials and
anaerobic environment are required for the formation of Biogenic Gas. Sand reservoir traps capped by
impermeable clay-mud layers would be useful for the occurrences of such gas beneficial for the local
people.
Results of seismic survey conducted in 2005 found out gas indications in the delta area of Kapuas river
mouth of Holocene or Quarternary sediments. In the delta environments, gas indications appeared as
seismic reflectors of acoustic turbidity, enhanced reflectors, acoustic blanking, multiple reflectors and
diffraction hyperbolas.
Drainage pattern of Kapuas River delta is a braided stream. This pattern has tendency channels changing
at periods hundreths to thousands years, thus this is causing sandy sediments become sand lenses acted as
gas reservoir. Drilling results up to depths 100 m found out sand layers at bor depth 35 up to 45 meters
covered up by mud layers. Mud occurs as organic mud enriched in carbon content which is predicted as
gas source with gas migrasion trapped in sand reservoir.
Field observation gas characteristics are demonstrated by strong odour of sulphur which is indication of
high content of H2S in gas composition. Observation also found out gas leakage to the atmosphere
through gas bubbles in swamp still water. During low tide, test by matches in this bubbles produced
flames. Gas existence was also characterized by lower acoustic velocity; 1333.33 m/second for sandy
PROCEEDINGS JOINT CONVENTION BALI 2007
The 32nd HAGI, the 36th IAGI, and The 29th IATMI Annual Convention and Exhibition
sediment and 1500 m/second for muddy layers. The supposed acoustic velocity for Holocene marine
sediments is approximately 1600 m/second.