I. Lazar et al., The use of naturally occurring selectively isolated bacteria for inhibiting paraffin deposition, J PET SCI E, 22(1-3), 1999, pp. 161-169
One of the most severe problems at any oil fields producing paraffinic oils
is that of paraffin depositions. Romania which has a long experience in oi
l production is also faced with this problem in many oil fields. The microb
ial treatment, based on the activity of naturally occurring, selectively is
olated bacteria, is already proved as an effective alternative to conventio
nal methods to prevent and remove paraffin damage. Using such kind of bacte
rial products, exciting results for inhibiting paraffin depositions have be
en obtained. In this paper results concerning the naturally occurring bacte
ria selectively isolated from hydrocarbon polluted sites as well as from pa
raffinic oils, semi-solid and solid paraffin depositions are presented. Aft
er a laboratory screening, 15 bacterial strains (BS 1-15), three bacterial
consortia(BC 1-3) and a Special Bacterial Consortium (SBC1) were selected.
For the selection of bacterial consortia, the classical enrichment culture
method has been used. The Special Bacterial Consortium resulted from a mixt
ure of BS 1-15 and BC 1-3 following the steps of the classical enrichment c
ulture method. The BS 1-15, BC 1-3 and SBC1 have been tested for their perf
ormances in producing biosurfactants and biosolvents as well as for hydroca
rbon utilisation. The SBC1 has been tested for its ability in degradation o
f hydrocarbons contained in several types of paraffinic or non-paraffinic o
ils, and then for inhibiting paraffin deposition on a 'flow equipment' usin
g two types of paraffinic oils. The SBC1 has been also tested for degradati
on of hydrocarbons contained in semi-solid and solid paraffin depositions.
The results obtained could support further applications to prevent and cont
rol paraffin depositions. (C) 1999 Elsevier Science B.V. All rights reserve
d.