The slides cover reservoir/fluid properties and production parameters of the Zhetybay oil and gas field located in Khazakstan. Information about geology, porosity-permeability, production and injection allow you to get an idea about drive mechanisms in the field.

1. Farida Ismayilova

2.  General information
 Parameters
 Advantages & disadvantages
 Water injection
 Summary
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3. -On top 15 for oil resources
-3.3% of world crude oil resources
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5.  19 x 5 km, field area: 77 km2
 Depth: 1500-2500m
 Reservoir dip: 3-50
 No major faults
 Trap: anticline
 STOIIP= 2.5 BBO,GIIP=1.2TCFG
 Current production rate: 21 MBD
 Ultimate recovery factor: 39 %
 Current recovery factor: 19%
Production rate:
1987 – 31 MBD
2015- 21MBD
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6.  13 layers
 HC type:
➢ light oil
➢ gas
➢ condensate
 Natural drive:
➢ moderate aquifer
➢ gas-cap
➢ solution-gas
No H2S!
good
bad
good
bad
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7. Discontinuous
sandstone=
lenses
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8.  Heterogeneous lithology
 Middle Jurassic sediments
 Gross thickness: 700m
 Oil column: 60m
 NTG=0.5-0.7
 Initial water saturation
➢ Oil:30-45%
➢ Gas:38-44%
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9.  Porosity: 16-22%
 Permeability: 6-115 mD due to:
➢ high clay content (up to 50% of the bulk rock volume )
➢ diverse grain size (fine-medium)
➢ poor sorting
Wide range of porosity and permeability
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10. ▪ Mature field
▪ Multilayer field
▪ Low dip angle(3-50)
▪ Moderate aquifer
▪ Low natural energy
▪ High heterogeneity
▪ Mobility ratio >1
▪ High initial water saturation(30-45%)
▪Onshore field
▪Multilayer field
▪No major faults
▪Low S content
▪No H2S
▪No sand issues
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11. Low energy system→ needs pressure support
Water injection efficiency is low
Reasons:
the disadvantages mentioned earlier result in
water fingering
▪ Mobility ratio >1
▪ Low dip angle(3-50)
▪ High heterogeneity
➢ Channelized system
➢ Discontinuous sandstone
➢ Moderate-poor vertical connectivity
Initial water saturation + water injected
→ high water cut
Other used methods:Artificial lift
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12.  No water drive, but depletion drive and the
production will continue to decrease without
enough pressure support.
 More surveillance, new technology and
investments are needed.
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