1. SUMMER INDUSTRIAL TRAINING AT ONGC
AGARTALA,TRIPURA
Topic- ROLE OF CIVIL ENGINEERS IN EXPLORATION & PRODUCTION OF
HYDROCARBONS
Presented by:-
Anamika Debbarma
DC2011BTE0127
7th Semester
Dept. of Civil Engineering

2. OIL AND NATURAL GAS CORPORATION
LIMITED(ONGC)
Oil and Natural Gas Corporation Limited (ONGC) is an Indian state-
owned oil and gas company headquartered in Dehradun, India
 It is one of the largest Asia-based oil and gas exploration and production
companies, and produces around 77% of India's crude oil (equivalent to around
30% of the country's total demand) and around 81% of its natural gas.
 ONGC is one of the largest publicly traded companies by market
capitalization in India.
ONGC was founded on 14 August 1956 by the Indian state, which currently
holds a 74.14% equity stake.
It is involved in exploring for and exploiting hydrocarbons in 26 sedimentary
basins of India, and owns and operates over 11,000 kilometers of pipelines in
the country.

3. ABOUT TRIPURA ASSET
ONGC started systematic geological mapping in Tripura in 1962 along with
shallow drilling at selected locations.
Almost the entire state has been investigated with the help of aerial
photographs, Landsat Imageries and detail to semi-detail geological mapping.
Structurally, Tripura Fold Belt which is a part of Assam Arakan Fold Belt is
characterized by series of parallel, elongated, and doubly plunging asymmetric
anticlines

4. GENERAL GEOLOGY

5. OIL EXPLORATION AND PRODUCTION:
AN OVERVIEW

6. Out of 26 identified basins, only seven petroliferous basins have been put
on commercial production. These are Mumbai offshore, Cambay, Assam-
Arakan including the Tripura-Cachar area, Cauvery, Krishna-Godavari,
Mahanadi and Rajasthan basins.

7. ROLE OF CIVIL ENGINEER IN HYDROCARBON
GENERATION
Offshore: Activities related to exploration and developments are carried out
both offshore (sea) and onshore.
1. Exploration Phase: During exploration stage, Jack up rigs which stand on
the legs and carry out the drilling activities from the drill floor are deployed. As
the legs of these rigs stand on the sea floor these are to be penetrated into the sea
floor so that stable base is provided for drilling of borehole.

8. Seabed Survey: This is carried out by deploying Survey Vessels which
contain Side Scan Sonar, Echo sounder etc.
 Using these equipments grid survey in N-S and E-W directions are
carried out at a spacing up of about 500m and in all directions up to a Km
surrounding the identified place.
 To reach the identified place Global Positioning System is used. The Side
Scan Sonar gives the seabed picture which indicates undulations in the
seabed as well as any obstructions.
 With the echo sounder bathymetry (Water depth) of the area is known.
Echo sounder works on the principle of sound wave reflection.

9. Geotechnical Investigation: There are specially designed offshore
vessels for carrying out Geotechnical Investigation.
 Soil investigation up to about 40m is carried out in ONGC to determine
soil characteristics i.e type of soil and bearing Capacity.
If soil is not having sufficient bearing capacity, there is likely of legs
punching through and with the result the rig becomes unstable and may
sink also. Hence soil investigation in offshore is a must prior to start of
drilling activities.
2.Development Phase:
Once reservoir is established, development wells are drilled and the
produced hydrocarbons are required to be transported to end users i.e. the
industries which use.
The produced hydrocarbons contain oil mixed with gas. These are to be
separated and for this purpose processing units are to be installed.
In offshore this is carried out at process platforms. It is a huge structure
for installation of these structures; various activities like design,
fabrication, transportation and installation are involved in the process.

10. Onshore: The role of Civil Engineers is challenging in Onshore Hydrocarbon
Exploration and Production.
1.Exploration Stage:
 Once location is identified for Hydrocarbon Exploration based on survey the
first step is to physically mark the location. This process is called stacking.
The work of Civil Engineers starts with stacking of location. Next activity
after stacking is Land Acquisition.
Civil Works at Drill site consist of following activities:
-Foundation for main rig.
-Ancillary Foundations for small units.
-Accommodation for drilling crew and security personnel.
-Hardening of site.

11.  Excavation of pits for waste material and also suitable measures to arrest
seepage of harmful chemicals to surrounding fields which may cause
damage to environment.
 -Providing water supply by suitable means i.e., by drilling tube wells at
site/laying pipelines from nearby wells/supply by tankers.
 -Construction of approach road.
 -Earth filling in case of low lying areas.
 -Earth cutting jobs in case of high ground.
 -Pile foundations in case bearing capacity of soil is very less.

12. 2.Production Stage:
 Once production is established, a common place called Group Gathering
Station needs to be established.
Group Gathering Station is a collection centre where hydrocarbons are
collected from different wells through pipelines.
 These hydrocarbons are separated into different components i.e. Oil, Gas
etc. through processing. After processing these components are sent to
different end users.
3. Various Stages of Execution of Work:
Once a work is identified , the first activity is to carry out preliminary
survey i.e. to examine the site condition so that cost estimates & land
acquisition proposals can be made.
 Soil investigation is also carried out to decide the type of foundation. If the
bearing capacity of soil is low, pile foundations may be required to be
installed.
Depending on the soil conditions, the design of foundations and other
structures is carried out

13. Development & Production
When exploratory drilling is successful, more wells are drilled to
determine the size and extent of field. These wells are called appraisal
wells .
Subsequent wells to extract hydrocarbons are called “development”
or “production” wells. After drilling these producing wells, the wells
are to be prepared for production before drilling rig departs.
The heavy drill pipe is replaced by lighter weight tubing in the well.
The commercial hydrocarbon wells are free flowing i.e., the
underground pressure drive the liquid and gas up the bore well to the
surface.
Once the hydrocarbon reaches the surface, it is routed to central
production facility through pipelines which gathers and separates the
produced fluids (oil, gas and water).

14. Civil Works in Tripura Asset,Agartala
Name of the work: ROAZ Agartala, Tripura Asset
Location: Near Sekarkote, Agartala; Tripura. It is Exploratory Location.
 Method of construction: Contractual method
Specification: Central public works department (CPWD)/ Tripura Public
Works Department (TPWD)/ Bureau of Indian standard

15. Estimated cost of the project:The estimate has been framed to Rs 1.89
Crore
Construction activities involved: Earth cutting in soil by mechanical
means with dozer, earth excavator, like machineries etc. including
cutting and pushing
Carriage of earth by mechanical transport including loading ,unloading
and stacking.

16. Providing and laying in position specified grade of reinforced cement
concrete 1:2:4 for Foundations
Reinforcement for R.C.C work is done with thermo-mechanically treated
bars or with cold twisted deformed steel bars.
Approach Road with Brick on edge Soling and flat Brick Soling
Area hardening by brick aggregates in two layers with proper
consolidation of sub base and top layers with 10 tonnes road roller with
vibrator.

17. Sheds with Brick wall, GI sheet roofing, false ceiling, doors windows etc.
Fire water Reservoir, over head water tank for water required in cooking,
Toilets Etc.
Shed with brick wall and GI sheet roofing for storage of chemicals.
Other miscellaneous works like Bamboo palasiding work for earth retain,
Platform for diesel Tank, Security huts etc as per requirement.

18. Name of the work:RODI Agartala, Tripura Asset
Location: Konaban GCS, Agartala. . It is Development location.
Method of construction: Contractual method
Specification: Central public works department (CPWD)/ Tripura Public
Works Department (TPWD)/ Bureau of Indian standard
Estimated cost of the project:The estimate has been framed to Rs 3.20
Crore.
Construction activities involved: Earth cutting in soil by mechanical
means with dozer, earth excavator, like machineries etc. including cutting
and pushing .

19. Carriage of earth by mechanical transport including loading, unloading and
stacking.
 Providing and laying in position specified grade of reinforced cement
concrete 1:2:4 for Foundations.
Reinforcement for R.C.C work is done with thermo-mechanically treated
bars or with cold twisted deformed steel bars.
Approach Road with Brick on edge Soling and flat Brick Soling
Area hardening By Brick aggregates in two layers with proper consolidation
of sub base and top layers with 10 tonnes road roller with vibrator.

20. Sheds with Brick wall, GI sheet roofing, false ceiling, doors windows etc.
Drilling and installation of Tube wells, Fire water Reservoir, Over head water
tank for water required in cooking, Toilets Etc.
Shed with brick wall and GI sheet roofing for storage of chemicals.
Other miscellaneous works like Bamboo palasiding work for earth retain,
Platform for diesel Tank, Security huts etc as per requirement.

21. CONCLUSION
After completing the summer training at ONGC Agartala, now we can
say that we have polished our book knowledge with our practical works
at different sites.
We have understood various techniques, process of production of
hydrocarbons, both offshore & onshore projects of ONGC.
 A civil engineer plays a vital role in today’s world. It may be planning,
estimation, construction etc in each & every department, a civil
engineer comes into the picture.
It has been a great experience in working with different engineers at
the site under the guidance of our mentor and we are grateful to both the
organization and the mentors.

22. THANK YOU