29-11-2012, 04:58 PM
Possibilities of Microbial Enhanced Oil Recovery implementation in the Danish chalk rocks
1Possibilities of Microbial.pdf (Size: 865.11 KB / Downloads: 282)
MEOR methods can be applied for:
•viscous oil to reduce oil viscosity by microbial decomposition of long-chain compounds,
•sour fields to reduce sulphur corrosion by injecting nitrate/nitrite,
•depleted fields by injecting biopolymer-generating bacteria and nutrients to block high-permeability beds,
•paraffin removal from well tubing,
•oil recovery enhancement by microbes producing gases (carbon dioxide and hydrogen) and other products of metabolism pressurizing oil reservoir, decreasing oil viscosity and increasing permeability.
The advantages of chalk rocks in comparison
to sandstones are:
•injected bacteria spread wider and more quickly through fissures, fractures and pure canals
•carbonates neutralize generated organic acids which inhibit microbial population growth
•permeability increases as the result of microbial rock solution, not yet drained sections of the reservoir rock are included in the recovery.
Gas analysis
Setupfor measuringthegas volumeproduced
•Determination ofH2S presencein thegas producedby microbes
•Treatment of white precipitate with acidified AgNO3 showed no production of a black substance showing that the test is negative. This proves that no traces of H2S are present in the produced gas.
•Therefore, precipitated is CaCO3 and gas produced is predominantly CO2.