Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
2.4 WELLS AND TRAILS CONSTRUCTION
0.99
Composition and parameters of the native gas of Surgil field for choice of the
gathering and treatment system are presented in the table.
Table 9 – Surgil field native gas composition
Name of rate
Value
Components volume fraction, %:
CH 4 89.51
C 2 H 6 4.563
C 3 H 8 2.23
iC 4 H 10 0.313
nC 4 H 10 0.39
C 5 H 12+higher. 0.99
H 2 S -
N 2 1.113
CO 2 0.89
Total 100
Density at 20 о С and 760mm Hg, kg/m 3 0.791
Relative gas density by air 0.656
Content of С 5+higher.
molar fraction, %
mass concentration, g/m 3 46.77
Molecular weight С 5+higher. , 123.84
Content of С 3
molar fraction, %
2.23
mass concentration, g/m 3 40.3
Content of С 4
molar fraction, %
0.703
mass concentration, g/m 3 18.55
Proceeding from mining and geological conditions of Ustyurt region fields, from
character of possible complications and experience of wells drilling, the following design of
new wells is recommended:
- cellar pit by 426mm diameter lower on 7m depth.
- surface casing by 299mm diameter lower on 150m depth for the purpose of
overlapping of sloughing and collapsed rocks in the top part of the wells
cross-section.
- intermediate column by 219mm diameter lower on 1900m depth proceeding
from a condition of prevention of hydro break of rocks during emergency
gas flowing from productive horizon.
Volume 2. Part 1. EIS Project for Surgil field construction
38