Oil and Gas Reservoirs and Coral Reefs, Figure 3 (a) Natuna L subsea depth structure in feet (from Eyles and May, 1982). (b) Natuna
sequence stratigraphy showing well correlations. Platform consists of alternating thick shallowing upward highstands (increasing
porosity) (i.e., highstand systems tracts) and thin deepening upward transgressive (decreasing porosity) deposits (i.e., transgressive
system tracts). Highstand deposits show porosity enhancement beneath subaerially exposed sequence boundaries (i.e., age date
surfaces) (modified after Rudolph and Lehmann, 1989).
Oil and Gas Reservoirs and Coral Reefs, Table 1 A partial list of significant Miocene-aged, coral reef platform oil and gas
fields, compiled from various sources, including references above (MMBOE million barrels of oil equivalent) (Pore types: Vug vuggy,
Mo moldic, Chalky chalky microporosity, BP Interparticle, WP intraparticle, Fr fracture, BC Intercrystalline, Ch channel, Cav
cavernous). Depositional components and pore types listed in order of abundance
Field name
Country
Depositional component
Porosity types
Estimated
porosity
range (%)
Estimated ultimate
recovery
(MMBOE)
Arun
Indonesia
Coral/algal/foram/molluscs
Chalky, Vug, Mo, WP, Fr
5–25
3,900
Kampung Baru
Indonesia
Coral/algal/foram/molluscs
Mo, Vug, Chalky, Fr
25–30
90
Krisna
Indonesia
Coral/algal/foram/molluscs
Vug, Mo, Chalky, Fr
10–35
55
Lho Sukon A
Indonesia
Coral/algal/foram/molluscs
Vug, Mo, Chalky
5–20
85
Liuhua
China
Coral/algal/foram
Vug, Mo, BP, WP, Chalky
15–35
115
Nido
Indonesia
Coral/algal/foram
Vug, Mo, Fr
1–10
20
NSO A
Indonesia
Coral/algal/foram/molluscs
Vug, Mo, Chalky, Cav, Fr
15–30
245
Natuna L
Indonesia
Coral/algal/foram/molluscs
Vug, Mo, BP, WP, Cav
10–30
26,250
Luconia F6
Malaysia
Coral/algal/foram/molluscs
Vug, Mo, BP,
5–35
740
Salawati A
Indonesia
Coral/algal/foram/bryozoan/
molluscs
Vug, Mo, Fr, BC
~15
20
Kasim
Indonesia
Coral/algal/foram/bryozoans/
molluscs
Vug, Mo, BC, Fr
5–40
60
Walio
Indonesia
Coral/algal/foram/bryozoans/
molluscs
Vug, Mo, BC, Fr
5–30
200
Rama
Indonesia
Coral/foram
Chalky, Vug, Mo, BP, WP
15–40
125
Bima
Indonesia
Foram/molluscs/coral/algal
Vug, Mo, Chalky, WP
20–40
90
Ramba
Indonesia
Foram/coral
Vug, Mo, Chalky, Ch, Fr
5–30
90
Bombay High
India
Coral/algal/foram
Vug, Mo, Chalky, Fr
15–25
5,015
Ras Fanar
Egypt
Vug, Mo, Chalky, BC, Fr
10–30
140
748
OIL AND GAS RESERVOIRS AND CORAL REEFS