Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
1.2 EXISTING SOURCES OF THE ANTHROPOGENIC IMPACT ON THE
ENVIRONMENT
The main sources of impact on environment in Surgil GCF region and pipelines for
transportation of field production are drilling production wells, building objects under
construction of Surgil field, existing constructions East Bardakh CGTU and Urga CGTU.
Feature of Surgil CGTU location is absence near large industrial objects.
Complex gas treatment plant (CGTU) East Berdakh is putted into operation in 2002.
Plant operating mode is continuous. Raw stock of CGTU is gas wells production of
East Berdakh, Uchsay field. Unstrapped combustible natural gas represents a multicomplex
mix of hydrocarbons and small quantity non-hydrocarbon components.
Table 2 – Natural gas composition arriving from East Berdakh CGTU to gas link of
CGTU East Berdakh-GMP Bukhara-Ural
Comp. С 1 Н 4 С 2 Н 6 С 3 Н 8 ICaH 1
0
nC 4 H 1
0
C 5 H 12 C 6 H 14 C 7+highest Н 2 S CO 2 N 2
% mole 94,24 2.73 0.78 0.114 0.14 0.1072 0.0621 0.0346 - 1.438 0.351 100.0
Gas of East Berdakh field according to its methane and homologs concentration is
dry, methane: according to non-hydrocarbon components content is nonsulfurous, carbon
dioxide (1.438%ab.). Methane content in gas is 93.837%ab. Nitrogen content is low
(0.495%ab.). Gas molecular weight is 17.3. Gas density at temperature 20 0 С is 0.791 kg/m 3 .
Presence of carbonic gas in raw stock defines its corrodibility, presence of
hydrocarbons – its explosion fire hazard.
The impact sources on environment are flare, tank farm and condensate pumphouse,
fire regenerator of DEG, fields of expulsion of produced formation waters.
Together with gas there are retrieved associated waters (formation water) on earth
surface. In the course of gas treatment the water is separated. The total volume of formation
water is 6570 m3/year. After water treatment on treatment facilities it will be dumped on
ponds-evaporators. The impact on environment rendered by sewerage will be limited by the
area of ponds-evaporators.
Emissions of harmful substances of East Berdakh CGTU in atmosphere do not create
a dangerous air gas contamination by one of components of pollutants, especially at distance
in Surgil GCF region.
Now there are 20 gas wells in operation in Urga gas condensate field. Gas gathering
is carried out according to the beam scheme by individual trails by diameter 159х11mm,
length 1250-3477m with gas transport to Urga GSP for the purpose of its treatment.
Urga GSP is intended for non-sulfurous gas pre-treatment from dropping liquid,
mechanical impurities and providing its normal pipeline transport through Bukhara-Ural gas
pipeline by diameter 1020mm.
Volume 2. Part 1. EIS Project for Surgil field construction
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