1. business and industrial
2. energy
3. oil

OIL AND NATURAL GAS CORPORATION
LIMITED
3
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
PROJECT DESCRIPTION
This chapter provides a condensed description of those aspects of the project likely to cause
environmental effects. Details are described in the chapter with regards to type, need, location, size
or magnitude of project operations, technology and other related activities.
3.1
3.1.1
Drilling of Exploratory Wells
Overview
To exploit hydrocarbon in sub-surface, an oil well is drilled by deploying a drill rig. Drilling operations
shall be conducted round-the-clock for 24 hrs. The time taken to drill a well depends on the depth of
the hydrocarbon bearing formation and the geological conditions. ONGC intends to drill wells to a
depth up to 3000 m. This would typically take ~30 - 35 days for each well – however drilling period
may increase depending on well depth.
In general, a 17 ½” hole is drilled from the surface up to a predetermined depth and 13 3/8” surface
casing is done to cover fresh water sands, prevent caving, to cover weak zones & to provide means
for attaching well head & the blowout preventer (BOP). This is followed by drilling of 12 ¼” hole and
lowering of 9 5/8” intermediate casing depending upon the depth of the well and anticipated problems
in drilling the well. The 8 ½” holes is drilled up to the target depth of the well cased with 5 ½”
production casing to isolate the producing zone from the other formations
In the process of drilling, drilling fluid is used to lift the cutting from the hole to the surface. Drilling
fluid is formulated by earth clay and barites. Various types of bio-degradable polymers are also added
to maintain the specific parameters of the mud.
Both two casing policy and three casing policy will be employed for drilling.
100M
13 3/8” casing
550M
1600M
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
9 5/8” casing
5 ½” casing
52
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Figure 3-1: Well Profile with Three Casing Policy
450M
1100 M
9 5/8” casing
5 ½” casing
Figure 3-2: Well Profile with Two Casing Policy
Where a hydrocarbon formation is found, initial well tests - possibly lasting one more month (if tested
by work over rig, which is smaller than a drilling rig) are conducted to establish flow rates of oil & gas
and formation pressure along with other reservoir parameters. These tests may then generate oil, gas
and formation water. On completion of testing, the well would be declared oil / gas producer or dry.


3.1.2
In the event that economic quantities of hydrocarbons are found, the well will be completed
with a wellhead in place, but all the other equipment and materials will be removed from the
site.
In the event that no economic quantities of hydrocarbons are found, the site would be
restored to the original form (as far as possible) and the well abandoned, following standard
practices.
Drilling Site Selection
The proposed well locations will be selected based on the following considerations:


Identified at a place so that drill site is located at a safe distance away from the nearest
village habitat & existing rain water catchment tanks;
Natural drainage channels are avoided or drainage channels rerouted to ensure
unhindered flow of rain / flood water. Where necessary adequate erosion control measures
will be provided;
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
53
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
All practicable means will be followed to avoid or minimize detrimental effects on the
surrounding environment by virtue of the construction at the location or the operation of the drilling
rig. Maximum care will be taken to avoid the cutting of the trees.
3.1.3
Site Clearance
The site selected for proposed drilling activity shall be first surveyed topographically and site
boundaries shall be marked. Land clearance for site construction at each drilling site shall practicably
be minimum in order to safely accommodate the facilities required for installation. The area of land
required would be approximately of the order of 110 m x 110 m.
During the construction phase of about 30 days, approximately 6-7 truckloads per day of material
movement would take place. The drill site construction would be done largely employing local labour.
3.1.4
Access and Transport
Roads will be required to provide access to each operating well and to the facilities provided for the
drilling. In some cases permanent access roads will have to be built so that equipment can be moved
in and out of the locations initially and during later maintenance. While preparing access roads,
following guidelines will be followed:



Use existing roads, when suitable, to prevent further soil disturbance
Site roads along ridgelines to minimize road grades and to lessen the potential of disturbing a
watercourse
Avoid designing roads with sharp curves, blind spots, steep grades in or near streams and
valleys
The transportation of the rig, drilling and well testing equipment to (and from) the drill site will be by
truck and trailer using the existing and proposed road system outlined above. 50 - 60 truck / trailer
loads are expected for delivery of this equipment over a ten day period.
3.1.5
Drilling Site Layout
Each development well drill site has the following facilities:












Potable office cabins / rest rooms;
Drilling rig foundation and cellar pit;
Foundation / pits for ancillary equipments;
Space for drill rig equipment, working area and materials lay down area;
Cutting disposal (impervious lined) pits;
Solar evaporation pits (waste drilling fluid disposal);
Water storage pit;
Sewage treatment system (septic tank with soak away pits);
Paved and contained chemical storage area;
Above ground diesel storage tanks with paved and bunded area;
Storm water drainage system;
Internal roads and fencing
Figure 3-3 provides a typical layout for such a drilling site. It should be noted however, that the final
configuration and layout would in part be determined by ONGC. Sheds shall be constructed for
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
54
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
accommodating the staff during working hours. A bunded oil, lubricants and chemicals storage area
will be installed and a shed shall be prepared for the same. A reinforced concrete pad will be built over
an area of around 20 m2 as a foundation for the drilling rig. A temporary waste containment area will
be constructed. A water pit with cement plastering will also be constructed for storage of water
required for the drilling operations. Once the site is prepared, drilling equipment, supplies and drilling
personnel will be mobilized and the drilling rig will be erected. The drill site is restricted access area
and is fenced all round with round the clock watch & ward facility. Entry of vehicles into the drilling
site area is prohibited except for material movement.
Instillation of Facilities
Within the cleared site, construction will be taken up. This would include the impermeable layer lined
for drilling fluid, drill cuttings, waste and water storage pits as required, foundations for the drilling
rig and accessories, inter-connecting drains, secure storage provision for chemical, oil and waste oil,
portable-cabins and a sewage treatment system (septic tank and soak away pits and piping). The
mobilization of the drill site involves transportation of drilling rig in modules and erected by means of
mobile cranes. The drill site equipments are designed as modular / skid mounted type, which
facilitates quick demobilization and re- mobilization. The installation of the drill site equipments /
facilities involves about 50 trailer loads spread over 5-6 days. Once the site is prepared, drilling
equipment, supplies and drilling personnel will be mobilized and the drilling rig will be erected.
Other Utilities
The development drill site area will be fenced by high barbed wire. The drilling rig will be positioned
almost in the middle of this area, when mobilized. Excavation work shall be carried out under the
permit-to-work system and in such a manner that the collapse of sidewalls is precluded. Measures
shall be taken to prevent persons and livestock from accidentally falling into an excavation pit.
Surface Drainage
Drilling sites will have an adequate drainage and wastewater conveyance system, so that all
wastewater are contained and can be disposed as per the GPCB discharge norms. The drilling rig
location will be connected with paved drains to the lined drilling fluid collection pits. Storm water flows
will be conveyed through surface drainage system. Surface drains will be adequately graded and
maintained and kept debris free to ensure quick disposal of their contents.
Waste Oil Collection, Storage & Disposal System
Waste oil from pumps or other machinery will be trapped and manually collected and stored in a
paved waste oil storage area. The storage area will be provided with paved flooring, containment
bunding and covered roofing. The storage facility shall be designed based on the CPCB guidelines for
hazardous waste storage. The waste oil will be recycled as per GPCB & MoEF authorized waste oil
recyclers at the end of the exploratory drilling operations.
Spill Containment System
Containment systems and oil traps will be provided to trap any escape of oil before it can leave the
drilling site. All potential sources of spillage will be equipped with drainage facilities or drip pans in
order to contain spills.
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
55
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Waste Water Storage Pit
The waste water storage pit (Size 70 m X 30 m X 2 m - for up to 3000 m well depth) will collect
waste water, which come from the drilling operations. The waste water present in the waste pits
will be recycled and reused during drilling phase. Water based drilling fluids, which are nonhazardous, will be used. The residual wastewater and the drilling fluid from the drilling operation will
be collected in waste pits for solar drying. The pit will be lined with HDPE sheet and the overlaps
welded together with the edges brought over the rim and tucked into the soil. At the end of the
drilling phase, the liquid fraction of the waste drilling fluid will be allowed to evaporate and the pit is
filled with thick layer of native top-soil.
Drill Cuttings Disposal Pit
The drilling rig system to be employed for drilling will be equipped for the separation of drill cuttings
and solid materials from the drilling fluid. The drill cuttings, cut by the drill bit, will be removed from
the fluid by the shale shakers (vibrating screens) and centrifuges and transferred to the cuttings
containment area. Once the drilling fluid / mud have been cleaned it will be returned to the fluid tank
and pumped down the drill string again.
Drill Cutting and drilling mud will be disposed off in accordance with Notification dated 30th August
2005 - G.S.R 546 (E) point no C “Guidelines for Disposal of Solid Waste, Drill Cutting and Drilling Fluids
for Offshore and Onshore Drilling Operation”.
Domestic Sewage Treatment and Disposal System
The domestic sewage generated from the drill site operations will be treated in a septic tank–
soak pit system. The septic tank is adequately sized to cater to a volumetric capacity of 4–5 m3 per
day.
Fuel & Chemical Storage Area
The fuel (Diesel) will be received in bulk quantity through road tankers and stored in above
ground steel diesel tanks (~ 40 KL capacity). The tanks will be operated and maintained as
per the applicable rules. The tank area will be provided with secondary containment of adequate
capacity to impound any accidental leaks.
Chemicals will be stored on a paved platform and protected against weather through an impervious
covering. Separate storages are earmarked for liquid and solid chemicals. All the storages are
identified with tags and sign boards. All required safety precautions such as display of the MSDS,
provision of fire extinguishers will be followed.
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
56
OIL AND NATURAL GAS CORPORATION LIMITED
EIA/EMP AND RA/DMP FOR DRILLING OPERATION OF 22
EXPLORATORY WELLS IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Figure 3-3: Typical Layout of Drilling Site
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
57
OIL AND NATURAL GAS CORPORATION
LIMITED
3.1.6
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Drilling and Testing Operation at Well Site
Once the cellar has been excavated, the drill pad constructed and equipments in place, drilling would
commence. Based upon the drilling methodology adopted by ONGC, the sizes of drill bits, casings
(surface / conductor / production) and other equipment would vary.
Typically for the first 100m or so a large diameter bit is used. A length of pipe, the casing, is cemented
into the shallow borehole produced to support the walls, which can be weak and porous and can
potentially collapse. The first drilling fluid used is quite often water alone. Drilling will then continue for
several hundreds of meters. At this depth smaller diameter casing is usually cemented into the hole.
This intermediate casing protects the well by sealing potentially weak zones. At this stage low density
drilling fluids will be used and although it is unlikely that gases or fluids under pressure might be
encountered, a blow-out preventer is typically installed as part of secondary well control to prevent
fluid from the formation gushing to the surface. Drilling continues using progressively smaller bits and
incrementally decreasing casing diameters. Air will also be used as drilling media wherever required.
Changes in fluid composition, and drill bit, are also likely to occur according to the different strata
encountered.
Drilling Mud
During drilling, a fluid known as “drilling fluid” or mud is pumped through the drill string, through the
drill bit and then returns up the annulus between the drill string and bore hole, serves a number of
important functions.
Drilling Mud Composition
ONGC uses water-based mud. The main components of drilling mud are slurry of inert solids
suspended in a liquid phase. The chemicals used for mud preparation are given in Table 3-1
Table 3-1: Chemical Used for Water Based Mud Preparation
Chemical
Percentage
Bentonite, 15cps
6
Potassium chloride
15
Polyanionic cellulose
0.5 (w/v)
Lignite
4.0
Caustic potash
1.0 (w/v)
Sulphonated Asphalt
2.0 (w/v)
Resinated Lignite
2.0 (w/v)
Biopolymer
1.5 (w/v)
Drilling Fluid Function
Drilling fluid serves the following essential functions:



The removal of drilled solids (i.e. cuttings) from the bottom of the hole and their transport to
the surface for separation from the mud;
Lubrication and cooling of the drill bit and string;
Deposition of an impermeable cake on the well bore wall to seal the formation
being drilled;
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
58
OIL AND NATURAL GAS CORPORATION
LIMITED


EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Suspension of drilling cuttings in the fluid during the interruption of drilling; and
Countering the natural formation pressures and preventing uncontrolled flow of fluid from the
formations
The role of the drilling fluids in pressure control is especially important. If the drill bit penetrates a
formation containing oil, gas or water under pressure these fluids are prevented from flowing into the
borehole by ensuring that the drilling mud is of sufficient density to the natural formation pressures.
Water based drilling fluids, which are of an environmentally acceptable nature will be used. The
drilling fluids are non- hazardous in nature and are normally re-used as much as is
possible while drilling the well.
Drilling Fluid Circulation System
During drilling operations mud is pumped through the drill string down to the drilling bit and
returns between the drill pipe casing annulus up to surface back into the circulation system
after separation of drill cuttings / solids through solids control equipment.
The mud used during the operation will flush out formation cuttings from the well hole. These cuttings
will be separated from the drilling mud using a solids-control and waste management package.
This will comprise a stepped system of processes consisting of linear motion vibrating
screens called shale shakers and centrifuges to mechanically separate cuttings from the mud fluid.
The mud from the hole is first screened in the shakers through a mud flow line which
separates 100 micron size of cuttings. The solids up to 2 micron are separated in a
centrifuge. The mud is then collected in mud tanks. Both the cuttings from the shale shakers and
centrifuge are collected in a Solid Discharge pit and then removed to a specially designed pit
lined with 1-1.5 mm thickness of HDPE. This cuttings pit has a certain slope to drain off water
in the adjacent waste pit. This pit after being filled up shall be covered with an impervious
liner over which a thick layer of native top-soil with proper top slope will be provided.
The whole process by which the drilling fluid will be reused during the drilling operation is commonly
known as a “closed loop system”. This system is ideal for drilling operations in sensitive environments
as it cuts down immensely on the total water consumption for the formulation of drilling mud and also
saves on the Consumption of chemicals. The circulating system is essentially a self contained, closed
system as shown in Figure 3-4
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
59
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Figure 3-4: Drilling Fluid Circulation System
3.1.7
Workforce Arrangements
No workers camp will be required during drilling of wells. During the drilling operations, about 30 to 40
persons may be working in 8 hour shifts at site. Workers will be able to return to their homes at night
and hence no camping will be required at or near the well site. Once drilling is over no person is
required at site, except security cover through a contractor.
3.1.8
Power Requirements
During drilling operations, diesel engines shall be utilized as prime movers for meeting the power
required to run the drilling rig, circulation system etc. A power generator shall also be installed for
lighting. The capacity of the diesel engines that shall be used for operating the rig and the circulation
system is expected to be of 1250HP (3 Nos, two running and one standby), which will be run by High
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
60
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
OIL AND NATURAL GAS CORPORATION
LIMITED
PROJECT DESCRIPTION
Speed Diesel. This generator shall consume approximately 250-300 Lit of fuel per hour, when in
operation. Besides, the power generator used for lighting is expected to have a rating of
approximately 40 – 60 KVA, which would consume HSD at the rate of 0.02 KL/hr, when in operation.
3.1.9
Water Requirement
The most significant requirement of water for drilling activities is for mud preparation.The other
requirement would be for engine cooling, floor / equipment / string washing, sanitation, fire-fighting
storage / make-up and drinking. During the drilling activity, about 35 m3 per day water will be
required which will include requirements for operation and that for sanitation and drinking of the
workers during drilling single well. The water shall be made available from the nearest ONGC
installation, and will be transported by water tanker. A water pit of 150 m3 capacity will be constructed
at the site for the purpose of fire fighting..
Table 3-2: Water Requirement
Peak water required during Drilling
period (KLD) per well
S. No.
Purpose
1
Mud preparation
10
2
Drill cutting washing, Floor and Equipment Washing
15
3
Engine Cooling
5
4
Domestic requirement
5
Drilling Operation
Total Water requirement for Drilling (KLD)
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
35
61
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Figure 3-5: Water Balance Diagram
Total Water Required
35 m3/day
8 m3/day
Drill Cuttings
Washing
General Rig
Washing
10 m3/day
10 m3/day
5 m3/day
2 m3/day
5 m3/day
Mud Preparation
Processing
2 m3/day
Cooling
Misc., Drinking,
Toilet Etc.
5 m3/day
5 m3/day
2 m3/day
Waste Pit
1 m3/day
Soak Pit
(Water recd.11 m3/day)
Net Waste Water Quantity: 3 m3/day
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
62
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
3.1.10 Waste Water Generation
The drilling operation would generate wastewater in the form of wash water due to washing of
equipment, string and cuttings etc. The only other source of wastewater generated from seismic
survey as well as drilling operation is sewage from sanitation facilities, which shall be disposed through
septic tanks/soak pits. It is expected that wastewater in the form of washings shall be generated at an
average rate of around 3 m3/day during the drilling operations from a single well. Waste water will be
discharged in HDPE lined evaporation pit, size of the pit is generally 70mx30mx2m.
The wash water would contain variable quantities of mineral salts, solids, suspended and dissolved
hydrocarbons, and other organic and inorganic components in very minor quantities.
3.1.11 Air Emissions
The emissions to the atmosphere from the drilling operations shall be from the diesel engines, and
power generator.
3.1.12 Noise Generation
The source of noise generation during this phase of operations would be the operation of rig and
diesel-generating sets. The expected noise generation at source, due to operation of rig is 101 dBA
(Source: "Control of Noise Pollution from Diesel Generator sets", Programme Objective Series;
PROBES/71/1998-99, Central Pollution Control Board). Besides, certain pumps are expected to be in
operation during this phase, for mud circulation. The noise generation work however is transient and
limited to the drilling period only.
Consultants from Kadam visited a typical ONGC drill site within the Cambay Basin; Noise levels were
measured near various noise generating equipments and at site boundary. The noise levels were
observed as follows





Near
Near
Near
Near
Near
Well head ~ 80 to 85 dB (A)
mud pump ~ 80 to 85 dB (A)
DG Set ~ 70 to 75 dB (A)
Shale Shaker ~70 to 75 dB (A)
Site Boundary ~ 55 to 60 dB (A)
3.1.13 Waste Management
The top layer of soil shall be stacked at site for reuse after completion of drilling operations. The solid
waste generated from drilling operation will be disposed in following manner.
Drill Cuttings – 150-200 MT / well will be generated, which are mainly inert solids. Drill cuttings shall
be water washed and then solar dried at site in HDPE lined cutting pit. Dry cuttings shall be covered
with top layer of soil.
Spent Oil – During the drilling approx. 200 lts. of spent oil shall be generated. This oil shall be sent to
authorized recyclers, as per ONGC policy.
Oil Sludge/ Hazardous waste – The proposed drilling is temporary activity and exploratory in nature,
no hazardous waste shall be generated. In case of any Oil Sludge/ Hazardous waste is generated
during the drilling activities, same shall be sent for incineration to a TSDF site.
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
63
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Drilling Mud – Water base drilling mud shall be used, approx. 200 m3 drilling mud per well is required.
Waste mud shall be sent to central mud plant of ONGC for processing, recycling and reuse.
3.1.14 Safety and Environment
Adequate safety measures such as fire-fighting equipment shall be provided at the site in accordance
with the norms of OISD 189. A high-pressure influx of formation fluids (water and/or gas) into the well
bore is commonly known as a 'kick'. Well control is aimed at preventing the kick and a possible
blowout. The function of well control can be conveniently sub-divided into two main categories,
namely primary well control and secondary well control. These categories are briefly described below.
Primary Well Control
This is the maintenance of sufficient hydrostatic head of fluid in the well bore to balance the pressure
exerted by the fluids in the formation being drilled. This means that the pressure exerted by the
density of the drilling fluid should be greater than the pressure of the formation fluids. It should be
noted that balancing formation pressure is a theoretical minimum requirement; good drilling practice
dictates that a sufficient excess of hydrostatic head over the formation pressure be maintained at all
times to allow for contingencies.
Secondary Well Control
If, for any reason, the effective hydrostatic head in the well bore should fall below formation pressure,
an influx of formation fluids (kick) into the well bore would occur. If this situation occurs, the Blowout
preventer (BOP's) must be closed to prevent the loss of fluid from the well. The purpose of secondary
well control is to rectify the situation by closing the well in and circulating the invading fluid out of the
well, while at the same time increasing the fluid weight to prevent any further influx.
The drilling personnel of the selected contractor are expected to be experienced in the above
procedures and the key personnel will be required to hold certificates to prove competence in well
control procedures. They will be trained and regular drills held to ensure that they will know how to
act in such events. Furthermore, they will be aware of the safety aspects associated with the drilling
operation, through training and experience. It must be also noted that blowouts are rare events during
development drilling operations conducted by experienced operators.
3.1.15 Abandonment of Operations
At the conclusion of the drilling program at each drilling site, an orderly withdrawal of all personnel
and the removal of all drilling and testing equipment and non-fixed items from the drilling site will be
undertaken.
Broadly, there are two such scenarios:


In case that the well is completed when economic quantities of hydrocarbons are found, the
well will be left with a wellhead in place, but all other equipment and materials will be
removed from the site. The well site will be fenced and will be reduced to 30m X 30 m for the
production phase and all non essential area will be fully reclaimed
In any other case the site will be cleared and refurbished to permit recovery to as near as
possible the pre-existing local environment
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
64
OIL AND NATURAL GAS CORPORATION
LIMITED
EIA/EMP AND RA/DMP FOR DRILLING
OPERATION OF 22 EXPLORATORY WELLS
IN NELP IX BLOCK CB-ONN-2010/1, 6
&9
PROJECT DESCRIPTION
Temporary Suspension of Activities
In the event that economic quantities of hydrocarbons are found, all empty drums, wastes, used and
unused drilling fluids, fuel and lubricants will be removed from the drilling site. Water supply and
effluent discharge hoses and associated equipment will be removed. All solids & liner will be removed
and sent to an authorized TSDF site.
Decommissioning upon Abandonment
In the event that no economic quantities of hydrocarbons are found, a full abandonment plan will be
implemented for the drilling sites in accordance with the applicable Oil Mines Regulation, 1984. The
activities mentioned in the above section would apply to decommissioning upon abandonment as well,
but abandonment would be more permanent.
The overriding principle being that the environment should, with time, be reinstated to broadly its
original condition. Until such time as this is achieved, ONGC would actively manage the reinstatement
process. All concrete or steel installations would be removed to at least 1 m below ground level, so as
to ensure that there are no protruding surface structures. In the unlikely event that soil is found to be
contaminated, measures would be taken to remove or treat appropriately all contaminated topsoil to
promote its remediation.
3.2
Cost of the Project
Approximate cost of the project is given in Table 3-3.
Table 3-3: Cost of Project
Description of the Activity
Approximate Cost
Drilling of 22 exploratory wells in NELP Block CB-ONN-2010/1,6 & 9
~ Rs 350 Crore
3.3
Details of Oil Collection System
As the proposed project is for exploratory drilling operation no oil/gas collection system is envisaged.
KADAM ENVIRONMENTAL CONSULTANTS | MARCH 2015
65
D
C
E
F
H
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I
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K
L
M
N
P
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R
Q
S
i
Da
p
ya
Rajkot
Study Area
Rampur
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To Daiya
3
Jampur
Gadsisar
Karbun
Savpura
Taluka Boundary
Road - NH/SH
Bhadodar
5
Chandangadh
Chothar Nesada
B
Fangadi
Tadav
7
Mahadevpura
THARAD TALUKADudhva
Idhata
Jamda
RANN OF KACHCHH
Bhachar
Achhuva
Lendau
Bhakhari
Dolatpura
Mahajanpura
Gambhirpura
11
Chuva
Golgam
Chudmer
Uchpa
THARAD
Well-7
Charda
Bukna
C
14
Ravla
Khimanavas
Vejagadh
Malsan
ASARAGAM
PADAN
Nagala
H
Moti Pavad
Z
AA
AB
AD
AC
AE
AF
Lalpur
Jetda
SH
-54
Peparal
Jasara
Achhavadiya
Chandarva
Del
Lembau
Sanavia
Kuwana
Lakhmi
Moral
Morikha
Chalva
Sanadhar
Nesda
Bhachali
Bhatvargam
Jelana
To Suigam
Koreti
Bahisara
Well-2
Vasarda
24
DEVPURA
(SUIGAM)
Devkapadia
Rampura
Bhatasana
26
Kalyanpura
Khari Paldi
To
am
ig
Su
Chatra
NH-15
Tetarva
Ravel
Jada Chamanpura
BHABHAR TALUKA
Bhambordi
Chaladara
Vadana
Forna
Liladhar
F
24°23'12.61"
71°29'41.80"
Well-08
24°28'8.46"
71°28'0.76"
Well-09
24°26'46.38"
71°30'25.13"
Well-10
24°14'29.08"
71°30'25.33"
Samla Vadana
Raiya
SH-70
Sadapura
(Jasali)
Jasali
Diodar
Mesra
Vakha
Nanota
Sanadar
Ludara
Mitha
KANKREJ TALUKA
Khodla
To Deesa
Boda
Bhadkasar
SCALE
0
Dhanakwada
Kotda Deodar
Salpura
Dhrandav
Bhodaliya
Khara
Well-07
Soni
Odha
Zalmor
Vakha
Karela
BHABHAR
71°30'41.30"
Duchakvada
Chagwada
Dhrandvada
Nesda
Abala
24°20'8.26"
Nava
Chimangadh
Surana
Mulakpur
2
4
6
8Km
KADAM ENVIRONMENTAL CONSULTANTS
871/B/3, Near Himalaya Machinery
GIDC, Makarpura, Vadodara - 390 010.
Tel: +91 (0) 265 2644909 / 2647 213
Fax: +91 (0) 265 2638411
E-mail: [email protected]
Delwada
Bhesana
Chembuva
Mespura
71°43'54.14"
Well-06
Navapura
Kunvarva
Kuvala
Barvala
24°12'59.77"
Kotada
Asana
Lunsela
71°40'33.07"
Well-05
Gangot
Vadiya
Abasana
Jorawargadh
DEODAR TALUKA
Sardarpura
Radakiya
Suthar Nesdi
Uchosan
Vatam Nava
Mojru Nava
Manvarpura
Radka
71°33'34.57"
24°14'38.32"
Manpura Jalodha
Narana
Khanodar
Rampura
Nokha
Harkudia
Balodhan
Sedhav
DUDHVA
Paldi
Well-3
Lalpura
Vatam Juna
Mojru Juna
Bhagwanpura
Kumbharkna
27
Manpura
Dhunsol
Mera
Eta
G
Well-5
Dhunsol
Vajapur Juna
24°10'40.52"
Well-04
Jalodha
Sesan Juna
Golvi
Vajapur Nava
Well-1
Khadol
Well-03
Dera
Sesan Nava
Golvo
Sanesda
Motipura
Benap
Ishvariya
Bhankhod
Chala Dhanana
71°32'38.20"
Vasna
Vajegadh
Rantila
Kunvata
Kotarwada
Janavada
71°30'12.10"
24°13'21.96"
Chibhda
Well-4
BHADVAL
Savpura
Mamana
23
D
Baiyak
Well-10
Limbala
Bharadava
Makhanu
Dethali
Tithgam
NH
-15
21
E
Makdala
Daua
Kanothi
24°11'27.02"
Well-02
Luvana
Sanav
Devpura
Talasar
Well-01
To Dee
sa
DEESA TALUKA
Golap
Dendava
31
Y
Lunawa
Khorda
Khardol
19
30
X
Asasan
Dharadhara
29
W
Gela
Nani Pavad
Madka
28
V
Jandla
Dodgam
17
25
U
Karnasar
Malupur
Khanpur
Well-6
Khimana Padar
T
SH
-54
Vavdi
15
16
Proposed Wells
Latitude (N) Longitude (E)
Malupur
Abhepura
Vav
Asaravas
era
Vadgamda
5
NH-1
Reluchi
CHATARPURA
an
Dh
To
28
SH-1
VAV TALUKA
13
22
Ghesda
Budhanpur
Sardarpura
12
River Beds
Janadi
Lodrani
Nalodar
Reservoir / Lakes / Ponds / Tanks
Gangana
Well-9
10
18
Water Bodies
Symbol /
Colour
2nd Classification
Residential / Commercial
Lunal
Dhima
Sapreda
Built-up / Habitation
Vami
Pratappura
Well-8
1st Classification
Lorwada
Takhatpura (Dhima)
Dheriana
Rachhena
Hathawada
Ghatiyali
Umedpura
8
Mangrol
Ganeshpura
A
6
9
Bhapi
Kolava
LAND USE LAND COVER CLASSES
Bhapdi
Bhorol
anch
ore
Chotil
To S
Haripura
Rabadi Padar
Road
Medhala
NH-1
5
Kareli
E
S
Project Site
Pirgadh
Baluntri
4
W
Symbol / Colour
Name
Patiyasara
2
Saba
N
LEGEND
Ajawada
TITLE OWNER PROJECT
B
To
A
1
EIA/EMP and RA/DMP for Proposed Exploratory
Drilling of Wells Block CB-ONN-2010/1
M/s ONGC Limited.
Map showing WELL LOCATION
in the study area
REVISION : 0
DRAWN BY : KK
SCALE : As Shown
CHD BY : SK
DATE : 21-03-2015
APPROVED BY : SK
DRAWING NO
M-3.1(A)
SOURCE : Satellite image taken from Enhance Version of Google earth pro 2013
nc
ho
r
e
N
Sa
Rajkot
Patiyasara
LEGENDS
Rampura
Saba
Gadsisar
Lunda
Savpura
STUDY AREA
Baluntri
Haripur
Bhapi
Ganeshpura
A
Fangadi
Umedpura
Lorwada
Takhatpura (Dhima)
Dheriana
Vami
Mahadevpura
NH-1
5
Idhata
Dhima
RANN OF KACHCHH
Sapreda
Achhuva
Dudhva
Lunal
Pratappura
Rachhena
RAILWAY LINE
Hathawada
B
Tadav
Chothar Nesada
ROAD
Bhapdi
Bhorol
Kolava
Chandangadh
TALUKA BOUNDARY
Bhadodar
Medhala
Rabadi Padar
E
S
PROJECT SITE
Jampur
Kareli
W
To
Vajiasra
Jamda
Idhata
THARAD TALUKA
Janadi
Bhakhari
Lodrani
Dolatpura
Gambhirpura
Nalodar
Chudmer
Chuva
Golgam
Budhanpur
Uchpa
Sardarpura
VAV TALUKA
THARAD
Abhepura
Charda
Reluchi
Vav
Khimanavas
Khanpur
C
Ravla
Malupur
Nagala
Malsan
Gela
Vavdi
Asaravas
H
Dodgam
Chandarva
Khardol
Madka
Nesda
Bhatvar Vas
Jelana
NH-1
5
Kanothi
Makhanu
Janavada
Chala
Bahisara
Vasarda
Narana
Ishvariya
Bhadrana
Golvo
Golvi
Sanesda
Sesan Nava
Bhankhod
Vatam
Vajapur
Khadol
Rampura
Navapura
G
Lalpura
Tetarva
BHABHAR TALUKA
Chaladar
Uchosan
NH-15
Chebua
Paladi
Baruvala
Sanadar
Dhrandvada
Lodra
Mitha
Vadana
Bhabbar
To Gandhidham
0
Diodar
F
Jasali
Sadapura
Rahia
KANKREJ TALUKA
Vakha
Surana
2
4
6
8KM
Odha
Jhalmol
Abala
SCALE
eesa
To D
KADAM ENVIRONMENTAL CONSULTANTS
871/B/3, Near Himalaya Machinery
GIDC, Makarpura, Vadodara - 390 010.
Tel: +91 (0) 265 2644909 / 2647 213
Fax: +91 (0) 265 2638411
E-mail: [email protected]
Chamanpura
Kotada
Kuvala
Nesda
Soni
Chagwada
Vadiya
Bhesana
Bhimbordi
Niladar
Jada
Phorna
Dhanakvada
Manvarpura
Chatra
Ravel
Nokha
Radka
Radka
Nesdi Sutar
Duchakvada
DEODAR TALUKA
Asana
Balodhan
Sedhav
Khanodar
Rampura
Sardarpura
Paladi Khari
Harkudia
Kumbharkna
Dudhva
Manpura
Kotada
Mera
Kalyanpura
Eta
Bhatasana
Benap
Dev
Manpura
Mojaru Juna
Paldi
Dhunsol
Motipura
Dera
Jalodha
Kunvata
Kotarwada
Dhanana
Manki
Vasna
Vajegadh
Kalji
Malupur
Mamana
DEESA TALUKA
E
Rantila
Chibhda
D
Baiyak
Savpura
Koreti
Luvana
Makdala
Dethali
Tithgam
Agthala
Sanav
Daua
Dendava
Lakhmi
Chalva
Devpura
Limbala
Bharadava
Sanavia
Talasar
Dharadhara
Moral
Achhavadiya
Kuwana
Lembau
Sanadhar
Bhachali
Peparal
Asasan
Del
Golap
Jetda
Jandla
Morikha
Jasada
Lunawa
Pavad
Khimana Padar
Malukpur
TITLE OWNER PROJECT
Bukna
EIA/EMP and RA/DMP for Proposed Exploratory
Drilling of Wells Block CB-ONN-2010/1
M/s ONGC Limited.
Map showing SATELLITE IMAGE
in the study area
REVISION : 0
DRAWN BY : KK
SCALE : As Shown
CHD BY : SK
DATE : 21-03-2015
APPROVED BY : SK
DRAWING NO
M-3.2(A
SOURCE : Satellite image taken from Enhance Version of Google earth pro 20
D
E
F
To Visnagar
H
To G
Vijapur
1
I
J
K
Tintodan
Himmatpura
Dhandhusan
2
To M
ahes
ana
Samou
Charada
Padusma
18
SH-2
To
he
Ma
Canal
Taluka Boundary
LAND USE LAND COVER CLASSES
Indrapura
Well-7
7
Vagosana
Well-6
Well-5
Jamla
Latitude (N) Longitude (E)
Pratap Nagar
Makakhad
Rampura
Ambod
Manekpur
Parbatpura
Well-3
Dhedhu
Rajpura
Dholakuva
Bhimpura
Delvad
KhorajDabhi
Sobhasan
Paliyad
Bhavpura
Soja
Itla
Nadri
KALOL TALUKA
Rampura
Pratappura
Vadu
Nava
Kotha
Narola
Balva
Well-2
11
72°34'0.92"
Well-03
23°23'39.86"
72°36'13.37"
Well-04
23°22'34.40"
72°36'13.37"
Well-05
23°24'20.60"
72°36'17.54"
Well-06
23°24'30.98"
72°35'9.11"
Well-07
23°24'48.51"
72°35'53.47"
Sadra
at
iR
Pindharada
GANDHINAGAR TALUKA
Vasan
Piplaj
Rupal
Pansar
SH
Sardhav
SCALE
ive
r
Unava
Jhulasan
Mokhasan
0
Chekhalarani
SH
15
To
Jalund
Kolavada
Adraj Moti
16
To
Gandhinagar
l
lo
Ka
Arsodiya
Jamnagarpura
K
To
l
alo
Bhoyan Rathod
Titoda
Ga
nd
hin
a
ga
r
TITLE OWNER PROJECT
-1
38
Dhamasna
6
8Km
871/B/3, Near Himalaya Machinery
GIDC, Makarpura, Vadodara - 390 010.
Tel: +91 (0) 265 2644909 / 2647 213
Fax: +91 (0) 265 2638411
E-mail: [email protected]
Randheja
Isand
4
KADAM ENVIRONMENTAL CONSULTANTS
-21
7
Sonipur
2
Anandpura
Dolarana Vasana
Vadavsvami
14
17
72°34'2.38"
23°21'17.12"
Aluva
Well-1
Nardipur
Bhadol
23°20'43.92"
Well-02
Mubarakpura
Dingucha
13
Well-01
Amaja
Golthara
12
Amarapur
Well-4
KADI TALUKA
10
Limbodara
Sa
ba
rm
a
san
ahe
To M
Karjisan
Ponds / Lakes / Tanks
River
Proposed Wells
Badpura
SH
-71
Himmatpura
Symbol /
Colour
Residential / Commercial
Water Bodies
Anandpura
Fatehpura
Gulabpura
Mansa
Boru
SH-217
ijapu
r
MANSA TALUKA
Itadara
Khata Amba
Veda
Bapupura
2nd Level Classification
Built-up / Habitation
To V
-71
SH
Parsa
To Prantij
Ridrol
SH
Solaiya
Kharna
SH-138
-13
0
a
san
Amarpura
Hadvi
E
S
1st Level Classification
Vadasma
W
Symbol / Colour
Study Area
Railway
Saldi
Dangarva
N
Name
Dhameda
6
9
LEGEND
Road
SH-73
Langhanaj
8
O
Harnahoda
Charadu
5
N
Proposed Site Boundary
Gozaria
4
M
MEHSANA TALUKA
Anandpura
Umiya Nagar
3
L
Vij
ap
ur
C
To
B
To Visnag
ar
A
EIA/EMP and RA/DMP for Proposed Exploratory
Drilling of Wells Block CB-ONN-2010/6
M/s ONGC Limited.
Map showing WELL LOCATION
in the study area
REVISION : 0
DRAWN BY : KK
SCALE : As Shown
CHD BY : SK
DATE : 21-03-2015
APPROVED BY : SK
DRAWING NO:
M-3.1(B)
SOURCE : Satellite image taken from Enhance Version of Google earth pro 2013
To Vijapur
N
To Visna
gar
To Visnagar
Tintodan
Himmatpura
Dhandhusan
E
S
Harnahoda
MEHSANA TALUKA
Charada
Padusma
218
SH-
Gozaria
LEGEND
To
Study Area
hes
Ma
Dhameda
SH
-13
0
Solaiya
Kharna
Parsa
B
Khata Amba
Itadara
Fatehpura
Gulabpura
Mansa
Boru
Himmatpura
Indrapura
A
Veda
Badpura
Pratap Nagar
Makakhad
Rampura
C
SH-217
Parbatpura
PART-B
Jamla
Ambod
Manekpur
Vagosana
Hadvi
Taluka Boundary
Anandpura
Saldi
Vadasma
Bapupura
MANSA TALUKA
Railway
-71
-71
SH
Langhanaj
Ridrol
SH
ana
Amarpura
Charadu
Proposed Site Boundary
To Prantij
SH-138
ToKalol
Symbol / Colour
Name
To V
ijapu
r
To V
ijapu
r
Samou
pu
r
SH-73
Vij
a
Anandpura
Umiya Nagar
To
To M
ahes
ana
W
Rajpura
Dholakuva
Bhimpura
Dhedhu
Delvad
KhorajDabhi
A
H
B
Sobhasan
Soja
Itla
E
Nava
Kotha
Balva
F
PART-A
D
G
KALOL TALUKA
Rampura
Pratappura
Vadu
Narola
D
Amarapur
Mubarakpura
Sadra
Nardipur
Unava
Dingucha
Jhulasan
E
F
Anandpura
Vasan
Piplaj
Rupal
Bhadol
Sardhav
SH
-21
7
Randheja
Sonipur
Dhamasna
To
Jalund
Kolavada
Adraj Moti
To
Gandhinagar
l
lo
Ka
Arsodiya
Jamnagarpura
lol l
Ka a l o
ToTo K
Bhoyan Rathod
Titoda
Ga
nd
hin
ag
ar
2
4
6
8KM
KADAM ENVIRONMENTAL CONSULTANTS
871/B/3, Near Himalaya Machinery
GIDC, Makarpura, Vadodara - 390 010.
Tel: +91 (0) 265 2644909 / 2647 213
Fax: +91 (0) 265 2638411
E-mail: [email protected]
Chekhalarani
Dolarana Vasana
Vadavsvami
Isand
0
Pindharada
GANDHINAGAR TALUKA
Mokhasan
Pansar
SCALE
Aluva
Amaja
Golthara
SA
BA
RA
S
abM
ana
Nadri
C
KADI TALUKA
Limbodara
G
TITLE OWNER PROJECT
Paliyad
Bhavpura
arA
mT
atI R
i RI
ivVeE
rR
Karjisan
SH
-1
38
s
ahe
To M
Dangarva
EIA/EMP and RA/DMP for Proposed Exploratory
Drilling of Wells Block CB-ONN-2010/6
M/s ONGC Limited.
Map showing SATELLITE IMAGE
in the study area
REVISION : 0
DRAWN BY : KK
SCALE : As Shown
CHD BY : SK
DATE : 21-03-2015
APPROVED BY : SK
DRAWING NO
M-3.2(B)
SOURCE : Satellite image taken from Enhance Version of Google earth pro 2013