The Effect of Physical Factors on Separation Efficiency of GAS From Oil Case Study in Alif Oil Field (Block 18)

Abstract

Oil produced from oil well often has large amounts of dissolved natural gas, which has not been released from oil
despite at lower pressure than saturation pressure. Therefore, it is necessary to separate these quantities of natural gas
from oil and access to oil to the state of stability, taking advantage of natural gas separated from oil economically.The
design of different types of technological separators depends on many factors affecting on the efficiency of their
work. The most important of factors are the pressure, temperature and geometric dimensions of the separator.In this
research, a large amount of field data (from the Alif field (block 18) were perused to investigate the effect of these
factors on the efficiency of the separating process of the natural gas from oil. The number of separation stages that
ensure the highest efficiency of natural gas was also identified. The optimum pressure for each stage of the separation
process in the Alif field (block 18) was determined. The flash calculation was used to investigate the effect of
pressure and temperature on separation efficiency of natural gas from oil flash calculation. The results show that an
increasing in pressure when the temperature is constant increases the efficiency of separation process. For example,
when the pressure separation is (90 psig) and the temperature is (155 0
F), (nL= 0.4595%), when the pressure increases
to (250 psig) and the temperature (155 0
F), the efficiency of separation process increases (nL= 0.5256%).The effect
of number of stages in the separation efficiency was also investigated. It was shown that increasing the number of
stages to five stages increases productivity from (0.45%) to (0.99 %.) The effect of the diameter of the separator and
retention time of oil inside in separator on efficiency of the process of separating the gas from oil was studied in this
paper. The increase in diameter of separator from (12,75 in) to (30 in) increases the efficiency of the separation
process by (33%), and the increase in the retention time of oil inside the separator from (1min) to (10 min) increases
the efficiency of separation process by (90%).