Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
However, there can origin emergencies during operation of the equipment of
designed constructions owing to pressure excess in pipelines, owing to formation of air-gas
mixture with concentrations capable to provoke explosion, with the subsequent gas ignition.
It is impossible to predict emergencies neither in the place of their origin, nor by
time. Therefore, there are supposed some assumptions during an estimation of parameters of
emergencies origin and their detrimental effect on people health and safety.
Scenario or type of failures is understood as a characteristic variant of emergency
process development.
Maintenance stuff of the enterprise can be object of effect. Quantitative estimation of
detrimental effect can serve as the estimation of possible irretrievable losses and sanitary
casualties.
Dangerous substances of oil and gas sector are characterized as fire - and explosive
(FE), and according to class can be concerned to class (D) - combustible gases under
pressure and to class (A) - combustible liquids.
Beaten zones are set by the form and the size concerning source of impact. Zone
edge can be approximated by circumference (C) or rectangle (R). For beaten zone in form of
circle the size is set by circle radius (R).
In the considered case we can assume that there was leakage of the connecting gas
pipeline.
This case belongs to the class (D), the failure scenario is (D1) - a fire. Beaten zones
have the form of concentric circles with the centre in a place of gas leak. Radiuses of beaten
zones depend on diameter of gas pipeline (parameter «Х») and are defined under the
formula:
где:
R = а * х + v,
а = 38.9. v = -1.7 – for irretrievable losses;
а = 105. v = 3 – for sanitary casualties.
R B = 38.9 * 0.820 + (-1.7) = 30m
R C = 105 * 0.820 + 3 = 89m
Thus, in a case of leakage of the gas pipeline by diameter of 0.820m and gas ignition
the radius of irretrievable losses will make 30m, and radius of sanitary casualties - 89m.
At these distances there can be only maintenance stuff of the enterprise as residential
zone is at rather remote distance.
Thus, at observance of all service instructions and safety engineering probability of
emergencies origin is low and in accordance with RD РД 118, priori frequency of failures
for pipelines makes 10 -5 .
Reliable trouble-free operation of designed objects is provided by strict observance
of the technological mode, all job descriptions as industrial, and on safety engineering, by
good technical training of the maintenance stuff.
Volume 2. Part 1. EIS Project for Surgil field construction
93