Formation conditions and exploration direction of large natural gas reservoirs in the oil-prone Bohai Bay Basin, East China
XUE Yong’an,WANG Deying
Table 2 Reservoir rock types of large and medium-scale gas fields around the world.
Gas field Lithology of reservoir Reservoir features Thickness of reservoir
ZEIT BAY buried hill oil and gas field in Gulf of Suez Quartz diorite, granodiorite,
granite, alkali granite, andesite
porphyry
The storage space is mainly composed of fractures, the development of which is controlled by faulting, diagenesis and inclination and direction of dyke and brecciated zone Oil reservoir: 295 m,
gas reservoir: 70 m
Bonger rift basins in Central Africa rift valley Cataclastic migmatitic granite,
migmatitic granite, and syenite
The storage space is made up of fractures and dissolved
pores, weathered crust and fracture belt form bi-layer
structure of reservoir in the bedrock
Greater than 300 m
Jatibarang oil and gas field in Indonesia Faulted volcanic rock, including
andesite, basalt, tuff, volcanic
breccia and agglomerate
With fractures, intergranular pores and intercrystalline
pore as main storage space, the reservoirs feature
strong heterogeneity and abundant fractures
Gas reservoir: 1200 m
Anyue gas field in Sichun Basin Granular dolomite and
crystalline dolomite
Dissolved pores, caves, fractures and structural
fractures constitute storage space
Up to 450 m
Kelameili gas field
in Junggar Basin
Basic-intermediate basalt,
andesite, acid rhyolite, volcani-
clastic rock and orthophyre
The storage space includes secondary dissolved pores
and structural fractures, volcanic breccia and basalt
form high quality reservoirs
Approximately 250 m
Xushen gas field in Songliao Basin Volcanic lava and
volcaniclastic rock
The storage space is made up of gas pores, dissolved
pores and high-angle and reticular fractures
70-400 m
BZ19-6 condensate gas field in the Bohai Bay Basin Gneiss, metamorphic granite,
migmatite, cataclasite and
morbruk rock
The storage space is composed of structural
fractures, intragranular fractures,
dissolved pores and dissolved fractures
Greater than 1500 m