1. AN ANALYTICAL STUDY ON
OIL& GAS PROCESSING IN A
PART OF THE UPPER ASSAM
BASIN
2. ACKNOWLEDGEMENT
• To the entire faculty of the Dept. of Petroleum
Engineering ,DUIET .
• To Mr. Sanjeev Thakur, Installation Manager, XY Oil
Collection Station ,OIL India Limited.
3. INTRODUCTION
The Upper Assam Basin consists of
Crude oils of API Gravity Range 15-
58°API with an average of 30°API. The
crudes are waxy in nature with a wax
content of 0.11 to 22 %. The Crudes are
of low Sulphur content (Sweet crude)
and of intermediate maturity.
4. METHODOLOGY
The XYZ processing facility
located in the Upper Assam
Basin is chosen and a
detailed study is undertaken.
The study includes the
plant’s overall infrastructure,
various facilities, operating
procedure, equipments,
installed capacities and the
well status.
6. WELL STATUS
Total no of wells connected : 37
Number of S/F wells on production: 16
Number of gas lift wells:20
Number of water disposal wells:06
Number of shut in well: 24
8. PROBLEMS ENCOUNTERED
a) Absence of Multistage
Separation Process
The pressure drop from 21Ksc to
5.5 Ksc is very large and may result
in the appearance of bubbles of gas
from the crude. This evolution of
gas and its subsequent expansion
acts as impairment in the
separation process resulting in the
improper separation of the three
phases in the crude hence resulting
in reduced performance of the
Three Phase Separator.
9. PROBLEMS ENCOUNTERED
b)Excessive wastage of gas in the
form of flaring
This leads to economic losses for the
operating company.
c)Inefficient Utilization of the
Separated Water
The separated untreated water from
the facility is disposed off at a depth of
1300m through water disposal wells.
10. PROBLEMS ENCOUNTERED
4. Absence of Automated Pipeline
Control System
This may lead to hazardous situations in
case of emergency.
5. Inefficient measures for sand control
The field under study has a problem of sand
production. But the design of the
equipments does not take into account this
problem
6. Absence of Mist Extractors on the
pressure vessels
11. POSSIBLE SOLUTIONS
1. Installation of one new
Intermediate Separator
The authors recommend the
installation of a new Three Phase
Separator between the GU-1(Wet) and
the preexisting TPS. The Set pressure
of the new separator must be
intermediate between that of the Group
Unit (Wet) which is 21Ksc and the TPS
(5.5 Ksc).The preferable range should
be 12-14 Ksc. The primary goal of this
is to reduce the intensity of the
pressure drop between the GU-1 (Wet)
and the TPS
12. POSSIBLE SOLUTIONS
2. Setting up of an Mini Effluent
Treatment Plant
The water separated from the crude can
be used for injection in the wells under
secondary recovery process.
3.Installation of a new Compressor
System
If a gas compressor is placed next to the
LPMS, the excess low pressure gas
which would otherwise have been flared
can be converted to high pressure gas
and distributed to the tea Industries of
the region.
13. POSSIBLE SOLUTIONS
4. Sand Control Issues
When excessive sand production is expected,
a cone bottom is placed in the vertical
separator to properly handle the sand.
5. Automated Pipeline Control Systems
To ensure that the pipeline can be monitored
for damage and dealt with effectively in case
of any damages.
6. Other Design Parameters
Mist extractors are recommended on the
pressure vessels to effectively remove small
droplets from the gas
14. ADVANTAGES OF THE NEW LAYOUT
Better Crude Processing
Environment Friendly
Energy Efficient
Enhanced Safety
17. CONCLUSION
Field processing assumes a lot of importance in oil
fields that produce waxy crude. This thesis is an
attempt to improve the quality of field processing in
one of the facilities of the Upper Assam basin. This
technology can also be applied to analogous field
processing stations in different parts of the world
(facing similar deficiencies in design) which have
similar reservoir characteristics to Upper Assam
Basin or having crude and natural gas with
comparable PVT Properties.
