1 INTRODUCTION ...... 1 1.1 Block Details ...... 2 2 PROPOSED PROJECT ...... 3 2.1 Project Details ...... 3 2.2 Project Justification ...... 5 2.3 Development Drilling...... 5 2.3.1 Infrastructure, Accessibility, Land Lease and Site Preparation ...... 5 2.3.2 Drilling Program ...... 8 2.3.3 General Requirements of Drilling ...... 8 2.4 Gas Gathering Station ...... 11 2.5 Pipeline ...... 12 2.6 Project Investment ...... 12 2.7 Project Schedule ...... 13 3 ECOLOGICAL SETTINGS OF THE AREA...... 14

List of Figure

Figure 1: Location Map of the Block Area ...... 1 Figure 2: Regional Setting Map ...... 4 Figure-3: Schematic Layout of the GGS ...... 12 Figure-4: Ecological Sensitivity Map ...... 15

List of Table

Table-1: Expected Cost of the Project ...... 12

a HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

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b HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

1 INTRODUCTION

The block AAP-ON-94/1 (area 305 sq. km) is located in Tinsukia district of Assam. The block lies between Latitude 27°18'54.99'' to 27°11'30.00'' North and Longitude 95°56'55.92'' to 95°20'00.00'' East. The block is bounded in the north by Digboi town and the Barajan, Tarajan and Jaipur settlements, in south by Tirap district of Arunachal Pradesh, in the east by Tirap River and in the west by Namrup and Hukanimuri settlement.

FIGURE 1: LOCATION MAP OF THE BLOCK AREA

The Block AAP-ON-94/1 was first awarded for exploration to Joint Venture Consortium by the Government of India (GoI). Production Sharing Contract (PSC) for Block AAP-ON-94/1 was signed on June 30th 1998. Presently, the JV Consortium of the block comprises of Hindustan Oil Exploration Company Limited (HOEC), Oil India Limited [OIL] and Indian Oil Corporation Ltd (IOCL). Hindustan Oil Exploration Company limited is the Operator and Oil India Limited is the Licensee of the block. The Participating Interest of the JV Consortium in the development phase is as follows: HOEC (26.882%), OIL (44.086%) and IOCL (29.032%).

March 2018 1 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

JV Consortium had acquired 2D/3D seismic data and drilled three exploratory and two appraisal wells in the block. Several sizeable prospects had been mapped and the Dirok wells drilled by the Consortium had confirmed the presence of multiple gas bearing sands. Based on the Dirok Discovery and subsequent drilling of appraisal wells in the block, which produced hydrocarbon from multiple sands from Girujan Formation; the Ministry of Petroleum and Natural Gas (MoPNG) had approved the Dirok discovery as commercial. Consortium has been granted Environmental Clearance for 2 exploratory drill sites via File No J-11011/50/2006-1A-II (I) during 2007. Public Hearing for the project was conducted at Ledo Railway Club, Ledo, Tinsukia. Pursuant to the aforesaid EC Consortium has drilled 2 exploratory wells within the Block. During 2009 another EC was granted to the Consortium via File no. NoJ-11011/112/2009-1A-II (I) for drilling of three exploratory wells within the Block. As part of this EC an exploratory well was drilled in the Block. During 2017 another EC was granted to the Consortium via File no. via File No. J-11011/245/2014-IA II (I) dated 31st January 2017 for six Development wells, Group Gathering Station (GGS), Gas Processing Plant (GPP) and 11.5 km Gas Pipeline from GGS to GPP. Public Hearing for the project was conducted at Uttar Margherita Rangamancha, Margherita, Tinsukia, Assam on 3rd July 2015. As part of this EC three existing wells put into production and three new wells were drilled. And construction of GGS, GPP and laying of Pipeline are in various development phase of the project.

1.1 BLOCK DETAILS

The block AAP-ON-94/1 is located in Assam-Arakan Basin and falls within geologically complex Schuppen Thrust Belt. It is located in Tinsukia District of the State of Assam, NE India. The nearby important towns are Duliajan (Head Quarters of Oil India Ltd) and Dibrugarh. Geologically the block falls within the Schuppen Belt of the Assam-Arakan Basin. The block lies south of the famous Digboi Field. Areas under reserve forest and Wild Life Sanctuary cover northern and western parts of the block respectively. In the central part of the block the river Dihing flows across the block from ENE to WSW. The southern part of the block is covered by uplands and hills. Rest of the area is covered by Tea Garden plantations. Opencast and underground coal mines operated by Coal India Limited are situated in the eastern part of the block AAP-ON-94/1. Dirok-1 is the discovery well in the block with number of gas bearing sands in Girujan Formation. Dirok-2 & Dirok-4 are appraisal wells with depth of 2500m TVD. The appraisal well DRK-2 was drilled on the same plinth within 40 m radius of DRK- 1. Dirok-4 was drilled on southern flank of Dirok structure at a distance of 2 Km

March 2018 2 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block towards NE. A total of 17 gas bearing sands in Girujan Formation are identified and will be developed in development phase to produce hydrocarbon.

2 PROPOSED PROJECT

2.1 PROJECT DETAILS

HOEC intends to drill 24 developmental wells and construct and commission a Gas Gathering Station (GGS) and approx. 5.5 km underground pipeline (GGS to Trunk Pipeline). Following project and facilities are planned: (i) Development drilling of 24 Nos of wells (ii) Setting up of two Gas Gathering Stations (GGS) within the block areas. (iii) Capacity expansion of existing Modular Gas Processing Plant (iv) Laying of flowlines (underground pipelines) to connect well location. (v) Laying of approx. 5.5 km underground pipelines from GGS to trunk pipeline (existing and connected with GPP). (vi) Laying of underground pipeline approx. 8km from existing GPP to IOCL terminal for distribution of gas. Drill Site 1 to 12 and 15 to 18 and GGS-2Dirok Tea Estate and Drill site 13, 14 and 19 to 24 and GGS-1 Powai Mukh, Janglu Kuruka village, Pipeline will be laid through Vitor Powai and Makum Pathar village. The GGS will be located at Vitor Powai village. Regional setting map of the proposed project development is presented in Figure 2.

March 2018 3 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

FIGURE 2: REGIONAL SETTING MAP

March 2018 4 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

2.2 PROJECT JUSTIFICATION

The hydrocarbons sector plays vital role in the economic growth of the country. With the ever increasing gap between the demand and supply in the hydrocarbons, the scenario is a challenge for India. India depends on imported crude to meet about 75% of its rapidly growing demand for petroleum products. The hydrocarbon resources available in the AAP-ON-94/1 Block is of immense importance for the country and will help in the growth of the economy and stride to reduce gap of crude oil imports versus self-sufficiency. The enhanced production will benefit the country by reducing the import bill and save foreign exchange and contribute to annual revenue to the Government of India.

2.3 DEVELOPMENT DRILLING

2.3.1 Infrastructure, Accessibility, Land Lease and Site Preparation

Accessibility The proposed drill sites falls within Tinsukia district of Assam and well connected with Digboi through NH 38. Dibrugarh is the nearest airport located at distance of 80 km from Digboi which is again directly connected to the metropolis of Kolkata and Guwahati. The nearest railway station is at Margherita. The major towns in this district are Tinsukia, Digboi, Margherita, Doom Dooma & Makum which are interlinked with each other through the NH-37 & NH-38. The NH-37 is the main road link between the district of Tinsukia and the rest of Assam and the country. From Makum Junction the NH-37 bifurcates and continues as NH-38 to the town of Digboi. The NH-38 serves as the main connecting link of all the 24 drill sites and the town of Digboi and Margherita. This is also the proposed route that will be used by HOEC for bringing in heavy drilling machinery and equipment. The Dirok area is connected with the state highway through Margarita-Deomali Road and Makum Killa Road. 13 drill sites south of Burhi Dihing River are well connected with internal roads of the Tea Garden. 6 drill sites north of Burhi Dihing are connected through Makum Killa Road.

Land Lease Proposed drill sites 1 to 12 and 15 to 18 located in Dirok Tea Estate and drill sites 14- 19 located in the villages Powai Mukh and Janglu Kuruka village. About 2.0 hectares (approx) of land for each drilling will be taken on long-term lease.

March 2018 5 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

Site Preparation

Site preparation will involve all activities required to facilitate the operation with the drilling rig and associated equipments and machineries. For the proposed drill sites the existing tea garden approach road and Makum Killa road will be widened, if required new approach road will be constructed. It will be ensured that the land fill material and gravel for this purpose is obtained from government approved borrow areas and quarries. Clearance of existing vegetation (Tea bushes and shed trees) at the drill sites will be carried out after taking permission from Dirok Tea Estate and Forest Department. Six drill sites would be constructed on agricultural land thus no vegetation clearance is required.

Once the approach road to the site is developed, the drilling site will be elevated to a required height. The top soil which primarily comprises of 150 mm loose top soil will be removed using mechanical means like dozer and saved at a nearby place for later use during site restoration. Leveling and compaction will be done with the help of graders and mechanical rollers. Earth and fill material and rubble will be required for land filling and site preparation. All such materials will be procured from government approved borrows and quarries. A backhoe will be used for all excavation and cutting activities (for construction of pits) on site. Subsequently, the proposed well site & campsite will be duly fenced using chain link and barbed wires. Disposal of drilling waste in the form of spent drilling mud and cuttings will be disposed on-site in specially designed pits provided with an impervious HDPE liner of 1-1.5 mm thickness. There will be a cuttings pit of 28m X 24m for disposal of drill cuttings and two waste pits of 17m X 12m for disposal of drilling mud and rig wash water. Platforms for drill pad and all other heavy equipment systems or machinery, cast in- situ Reinforced Cement Concrete (RCC) will be used for the construction of foundation system. The rig foundation will be of size 20m X 20m and will have an elevation 0.6 m from rest of the site. For making the foundations of main rig structure cast in-situ bored under- reamed piles of specified lengths will also be used. The elevated structures will have proper storm water drains with sufficient gradient, made of brick masonry, to take care of surface runoff water. The transport of the Rig including auxiliary equipment & Camp facilities to the site is expected to comprise around 100 truck loads. Though the rig and related equipment will be directly brought to site, spares, chemicals and other materials will be received at the staging point and will be used for intermediate storage of materials. The rig equipment will however be transported directly to the drilling site

March 2018 6 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block during mobilization and will be de-mobilized directly from the site. The materials will be intermittently supplied from warehouse to the drilling site, during the operations with some stock at the drilling site itself. Given the sensitivity of the site from the noise emission viewpoint, it has been decided that all construction activities and transportation of goods and equipment related to such activities will be restricted to the extent possible to day time. Drilling operations will be carried out using an Onshore Mobile Drilling unit. The major components of drilling unit are Hoisting system, Rotating Equipment, Circulating System, Tubular Goods, Pressure Control, Derrick and Substructure. The hoisting system consists of draw works an assembly of a rotating drum, a series of shafts, clutches, chains and gears for changing speed and for reversing. A crown block located at top of derrick. The crown block provides a means of taking the drilling line from the hoisting drum to the traveling block. The crown block is stationary and is firmly fastened to the top of the derrick. The Hook connects the Kelly or top drive (top drive is equivalent to Kelly & rotary table) with the traveling block. A Kelly drive refers to a type of well drilling device on an oil or gas drilling rig that employs a section of pipe with a polygonal (three-, four-, six-, or eight-sided) or splinted outer surface, which passes through the matching polygonal or splinted kelly bushing and rotary table. This bushing is rotated via the rotary table and thus the pipe and the attached drill string turn while the polygonal pipe is free to slide vertically in the bushing as the bit digs the well deeper. When drilling, the drill bit is attached at the end of the drill string and thus the kelly drive provides the means to turn the bit. The Kelly is the polygonal tubing and the Kelly bushing is the mechanical device that turns the Kelly when rotated by the rotary table. Together they are referred to as a Kelly drive. The upper end of the Kelly is screwed into the swivel, using a left- hand thread to preclude loosening from the right-hand torque applied below. The Kelly typically is about 10 ft (3 m) longer than the drill pipe segments, thus leaving a portion of newly drilled hole open below the bit after a new length of pipe has been added and the drill string has been lowered until the Kelly bushing engages again in the rotary table. The rotary table receives the power to drive it from an electric motor. The electric motor rotates the rotary table which passes through the Kelly bushing and the rotations are transmitted to the bit as the drilling progresses, the drill pipe in singles are added to continue the drilling process. At the end of the bit life, the drill pipes are pulled out in stands and stacked on the derrick platform. A stand normally has 3

March 2018 7 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block single drill pipes. After changing the bit, the drill string is run back into the hole and further drilling is continued. This process continues till the target depth is reached. During the course of drilling, cuttings are generated due to crushing action of the bit. These cuttings are removed by flushing the well with duplex/triplex mud pumps. The mud from the pump discharge through the rotary hose connected to stationary part of the swivel, the drill string and bit nozzles. The mud coming out of the bit nozzles pushes the cuttings up hole and transports them to the surface through the annular space between the drill string and the bore hole. The mud not only carries away crushed rock from the bottom of the hole but it also cools the bit as it gets heated due to friction with formation while rotating. The mud also helps in balancing subsurface formation pressures and by forming a mud cake on the walls of the well diminishes the possibility of crumbling or caving of the well bore. At the surface, the mud coming out from well along with the cuttings falls in a trough, passes through the solids control equipments i.e. shale shaker, de-sander and de-silter. These equipments remove the solids of different sizes which get mixed with the mud during the course of drilling. The cleaned mud flows back to the suction tanks to be again pumped into the well. The drilling mud/fluid circulation is thus a continuous cyclic operation. The most suitable clay for mud preparation is bentonite which is capable of forming highly dispersed colloidal solutions. Various other chemicals are also used in mud preparation as per requirements dictated by the temperature/pressure conditions of the wells. The mud is continuously tested for its density, viscosity, yield point, water loss, pH value etc. to ensure that the drilling operations can be sustained without any down hole complications.

2.3.2 Drilling Program Drilling is a temporary activity which will continue for about 40-50 days (only drilling & formation evaluation) for each well in the block, but the number of days will vary based on depth and type of well. The rigs are self-contained for all routine jobs. Once the drilling operations are completed, and if sufficient indications of hydrocarbons are noticed while drilling, the well is tested by perforation in the production casing. This normally takes 7-8 days. If the well is found to be a successful hydrocarbon bearing structure, it is suspended for future development, if any.

2.3.3 General Requirements of Drilling Drilling program requires the following common facilities:

Drilling mud

March 2018 8 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

Drilling of wells requires specially formulated mud which basically comprises inert earth materials like bentonite, barite in water with several additives to give mud weight, fluidity and filter cake characteristics while drilling. The drilling mud have several functions like lubrication and cooling of the drill bit, balancing subsurface formation pressure, bringing out the drill cuttings from the well bore thixotropic property to hold cuttings during non-operations, formation of thin cake to prevent liquid loss along well bore etc. Several additives are mixed into the mud system to give the required properties. Water based mud will be used to the possible extent in development drilling.

Power Supply The power requirements at the site development and construction phase will be met by DG Sets. Although the drilling operations will be continuous, the power requirement will vary depending on the activities being carried out. It is anticipated that four diesel-engine generators, each with a capacity of 670 kW, will be sufficient for rig operations. Three generators will be used at a time and one will be kept on standby. A 134 KW generator will be made available for lighting and other emergency requirements.

Water Consumption and Supply The total water requirement for the site preparation and construction phase of the project is estimated to be about 1200 KL per well. With average time requirement for site preparation being about 60 days, it means about 20 KLD of water will be consumed on an average every day for each well. The total projected average consumption of water during the drilling phase will be about 1500 KL with a maximum of 45-50 KLD being utilized to run the drilling rig continuously, 24hrs a day. Water would be sourced from surface water sources through local authorized vendors. Potable water requirement at site will be met through filtered bore well water and packaged drinking water.

Domestic wastewater The operating personnel in the drilling rigs will operate from drill site accommodation (DSA) in the vicinity of the location. Suitable soak pits will be available at the DSA.

Solids removal

March 2018 9 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

The rock cuttings and fragments of shale, sand and silt associated with the return drilling fluid during drilling which will be separated using shale shakers and other solids removal equipment like de sanders and de silters. The recovered mud will be reused while the rejected solids will be collected and discharged into the waste pit.

Drill cuttings and waste residual mud

During drilling operations, approximately 450-500 cum wet drill cuttings are expected to be generated from each well depending on the type of formation and target depth of well. In addition to the cuttings 15-20 cum/day of wastewater is likely to be generated during well drilling. The waste residual mud and drill cuttings which contain clay, sand etc. will be disposed into the waste pit.

Testing Testing facilities will be available at drilling rig for separation of liquid phase and burning of all hydrocarbons during testing. The test flare boom will be located at a distance from the drilling rig.

Fuel Consumption The fuel consumed will mainly be diesel used by rig, various equipments, and vehicles operating to transport goods and supplies to the site. During the drilling phase, the consumption of diesel is estimated to be about 4.5-5 KLD. Out of this, a major part comprising about 85% will be consumed by the rig (also including the DG sets) and about 15% will be required for the campsite. There will be provision for storing about 7-9 days of fuel which means storage of about 35 KL. The fuel will be provided by the drilling contractor and transported to site in tanker lorries.

Resource & Chemical Usage Various chemicals will be used during the drilling phase, mainly for preparation of drilling mud. At the planning stage, an estimate of the potential usage for every chemical will be made and documented in chemical usage tracking sheet. During the operation chemical usage will be monitored and efforts will be made to reduce or conserve chemical usage as much as technically feasible.

Manpower / Employment The project will be employing considerable manpower for all the phases. The Site preparation phase of 60 days will employ on an average about 45 to 50 workmen, preferably from local settlements. The total number of personnel involved in the drilling activities is expected to be about 40 to 60. At any one time there will be 20-30 staff and security personnel on the

March 2018 10 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block well site thus a camp site will be set up to provide boarding & lodging. Rest of the staff will be housed in Digboi and will continue on 12hrs shift basis to the well-site. It must also be mentioned here, that the site development activities including the transportation of heavy equipment and machinery to site may involve the temporary shifting of some existing utilities like overhead power lines, phone lines, water pipelines which will be restored with high priority.

2.4 GAS GATHERING STATION All the development wells 1-12 and 15 to 18 will be connected to Gas gathering Station (GGS) located at Dirok-4/ proposed GGS-2 well site within Dirok Tea Estate. Wells 13, 14 and 19 to 24 will be connected to the proposed GGS at Vitor Powai Village. Area of the proposed GGS would be approximately 1 ha. Gas gathering lines/systems will be installed as part of the project in Dirok oil/gas block for accumulation and transportation of raw natural gas directly from wellheads to the GGS. Gas extracted from gas wells will be sent to the gathering stations by controlling the gas pressure at wellheads. The pipelines from the wells to GGS (total length) will be constructed conforming to international ANSI/API and also OISD standards as per best industry practice. The pipelines will be of buried construction with a minimum earth cover of 1.0 mtr. Gas that will be produced from the wells contains some amount of Condensate or Natural Gas Liquid (NGL) and sometimes small amount of saturated formation water. This entire fluid from the wells will be transported through by a single pipeline through a manifold within the GGSs to the existing facility at Kusijan via the existing Gas Processing Plant (GPP) at Golai village. The schematic layout of the GGS is presented in Figure 3.

March 2018 11 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

FIGURE-3: SCHEMATIC LAYOUT OF THE GGS

2.5 PIPELINE 12 inch diameter gas pipeline of approximately 5.5 km gas pipeline will be laid along the RoW of the existing Makumkila road to transport the natural gas from proposed GGS at Vitor Powai village to existing trunk pipeline. The proposed pipeline from the GGS would cross Pawai Nala on its way to Trunk Pipeline. An underground pipeline approx. 8km will be laid from existing GPP to IOCL terminal for distribution of gas The pipeline will be laid conforming to the international ANSI/API and also OISD standards as per the best industry practice. The proposed pipeline will be laid and buried at a depth of 1.2 to 1.5m alongside the existing road.

2.6 PROJECT INVESTMENT The total cost of the project would be approximately USD 85 million. Cost break-up of individual components is presented in Table 1.

TABLE-1: EXPECTED COST OF THE PROJECT

Sl. Field Development Approximate Cost (million No. USD) 1. Development Wells (24 nos, including field 72 pipelines connecting to GGS) 2. Two nos. of GGS 3 3. Pipeline (Approx 13.5 Km) 3 4. Expansion of GPP 7 Total 85

March 2018 12 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

2.7 PROJECT SCHEDULE

The tentative project schedule is as follows;  Rig Mobilization: April 2019  Drilling of wells : May 2019 onwards (50 days per well)  Laying of pipelines: October 2019 to May 2020  Commissioning and Construction of GGS : January 2020 to August 2020  Capacity expansion of M-GPP : January 2020 ( 120 days approx.)

March 2018 13 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

3 ECOLOGICAL SETTINGS OF THE AREA

The Upper Dehing Reserved forest is famous and is also known as rain forest. The entire forest of the Dehing-Patkai region houses many endemic species and the forest are of multistoried types with five canopy layers. The first canopy is covered with luxuriant growth of Hollong, Titasopa and Borpat etc. The second canopy consists of Nahar with Sam, Mekai, Amari, Kadam, Bhomora, Barhomthuri, Bhelkor, Bogipoma and Bhola. The third canopy is mainly dominated by Morhal, Ajar, Mej, Owtenga, Bajiow etc. The fourth canopy is mainly covered by woody shrubs like Kaupat, Tora, Bogitora etc. Palms like Geruga, Tamul, Tokopat, tree ferns, cranes, woody climbers like oblonga are also common. The ground flora consists of various shrubs like Bon Moduriam, Bon posola, Dhopat tita, Digholti etc. Dehing Patkai Sanctuary has been notified with the total area of 116 sq. km., consisting of Upper Dehing (West Block) Reserved Forests, Dirok and Joyopore. The sanctuary is famous for many species such as Asian Elephant, Royal Bengal Tiger, Hoolock Gibbon, Leopard, Jungle Cat, Barking deer, Bison, Bear, Common Monkeys, Slow Loris, Flying Squirrel, Mongoose, Pangolin Great Indian Civet, Bat, Giant Bat, Birds like Winged Wood Duck, Hornbill, Kingfisher, Woodpecker, Myna, Dove, green pigeon, Barbet, Bulbul, Vulture, Kite, Hawk, Owl, varieties of cranes, Darter, Stork, Cormorant, Monitor Lizard, Python, Viper , Cobra and many more varieties of poisonous and non-poisonous snakes. The proposed wells and GGS is located with 5 km of the wild life sanctuary. Ecological Sensitivity map of the area is presented in Figure 4. The Dehing Patkai Elephant Reserve with total area of 609.55 sq. km. and a total of 160 wild elephants. The established elephant corridors in the Digboi Forest division are described below [Source: Right of Passage: Elephant Corridor of India; WTI, 2004].

March 2018 14 HOEC Drilling of Wells, Construction of GGS, Pipeline- AAP-ON-94/1 Block

FIGURE-4: ECOLOGICAL SENSITIVITY MAP

March 2018 15 HOEC

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