PRE-FEASIBILITY REPORT Executive Summary The proposed area covering the Borholla ML, Mekerong ML, Titabar ML, Golaghat Extn IIA ML, Golaghat Extn IIA (addl) ML, East Lakhibari Extn. ML, Kalyanpur ML falls within Jorhat and Golaghat District of Assam state. The area has an average elevation of about 100 metres above mean sea level. It is bounded by the state of Nagaland to the east. Jorhat Asset is planned to generate 53 no. of locations in the fields of Borholla, Mekrang Dayalpur, Jantapathar, Babejia, Hazarigaon, East Lakhibari and Kalyanpur in next five years. These locations will be drilled in non-forest area of each ML. Most of the ML are having multilayered reservoirs and contributing more than 50% of Assets production. The locations are falling in revenue land of Boroholla ML, Titabar ML, Mekerang ML,Golghat Ext-IIA(addl) ML, Golaghat Extn IIA ML, East Lakhibari Extn. ML and Kalyanpur ML. Borholla field is one of the largest fields of Jorhat Asset. The field is having multilayered reservoir and contributes around 30% of Assets production. Presently one EOR scheme is going to be implemented shortly and it not only enhance the recovery but also help to maintain reservoir health. Pressure maintenance scheme in the form of Water Injection is also lined up for implementation shortly. The field has enormous potential and study in GEOPIC and IRS is in progress to generate more locations in future. Dayalpur field is the youngest and most promising field of Jorhat Asset. The first well DPR-01 was drilled and put on production in 2016. The field is having multilayered sands and contribute around 70 tpd. Few more exploratory locations are lined up for drilling in western part of the field and based on the exploratory there will be a scope to generate few more locations in future to enhance the production level. East Lakhibari, Kalyanpur and Babejia, are satellite oil fields of Jorhat Asset and contribute around 11% of Assets oil production. Hazarigoan and Jantapathar are potential gas fields of Jorhat Asset and presently temporarily abandoned due to lack of consumers. The production of these locations will contribute immensely to the 10 % import reduction target as envisioned by our honorable prime minister for achieving energy independence. The crude oil produced from the proposed wells will be send to already existing Group Gathering Station (GGS) at Borholla. ONGC has tentatively planned to drill 53 locations in non-forest area of above mentioned ML and after necessary approval an investment approximately Rs-1325 crores in phase wise manner is tentatively planned in next few years in these fields. 1.0 Introduction/Background The Borholla PML, Titabor PML, Mekrang PML, Golaghat Extn IIA (addl) PML, Golaghat Extn IIA PML, East Lakhibari Extn. ML and Kalyanpur ML covers respectively 32.12sq. Km, 10 Sq.Km, 16 Sq. Km, 61 Sq. Km, 24 Sq. Km, 49 Sq. Km and 40 Sq. Km of South Assam Shelf Block in Jorhat and Golaghat district, Assam. It is planned to generate 53 nos. of locations in these ML in near future. It is expected that drilling of these locations will lead to augment the production of hydrocarbons in the present scenario of growing demand of oil and gas in the country. I) Borholla ML The Borholla ML is covering an area of 32.12 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Borholla ML is a major hydrocarbon producing field in Dhansiri Valley of A& AA Basin and already established for multiple deeper plays like Fractured Basement, Tura, Sylhet, Kopili and younger plays like Tipam & Girujan (for Gas) with multi-stacked hydrocarbon play. The hydrocarbon has been put into production in this PML since 1970. The Borholla ML has been applied for re-grant of ML in June 2017 (initial ML period was from 17.06.1998 to 16.06.2018). Waiting for Re-grant from MOP&NG. ONGC, Jorhat Asset is planning to generate 10 more locations in coming years. ii) Mekerong ML The Mekerong ML Block covering an area of 16 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Petroleum Mining lease grant for Mekerong ML was received for a period of 20 years w.e.f. 19.09.1997. Regrant of Mekerong ML block was again received in 2018 for another 20 years. ONGC, Jorhat Asset is planning to generate 5 more locations in coming years. iii) Titabar ML Titabar ML covering an area of 10 SKm is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The ML period for Titabar block was granted for 20 years from 24.12.2008 to 23.12.2023. ONGC, Jorhat Asset is planning to generate 10 more locations in coming years. iv) Golaghat Extn IIA ML: The Golaghat Extn IIA ML covering an area of 24 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Petroleum Mining lease grant for Golaghat Extn IIA ML was received for a period of 16 years w.e.f. 09.12.2009. ONGC, Jorhat Asset is planning to generate 7 more locations in coming years. V) Golaghat Extn IIA (addl) ML: The Golaghat Extn IIA (addl) ML covering an area of 61 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Petroleum Mining lease grant for Golaghat Extn IIA (addl) ML was received for a period of 7 years w.e.f. 27.02.2017. ONGC, Jorhat Asset is planning to generate 11 more locations in coming years. VI) East Lakhibari Extn ML: The East Lakhibari Extn ML covering an area of 49 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Petroleum Mining lease grant for East Lakhibari Extn ML was received for a period of 7 years w.e.f. 10.10.2013. ONGC, Jorhat Asset is planning to generate 5 more locations in coming years. VII) Kalyanpur ML: The Kalyanpur ML covering an area of 40 SKM is located in the South Assam shelf part (Dhansiri valley) of A&AA Basin. The Petroleum Mining lease grant for Mekerong ML was received for a period of 20 years w.e.f. 13.04.2007. ONGC, Jorhat Asset is planning to generate 5 more locations in coming years. 2.0 Description of Project 2.1 Proposed Project The Borholla ML, Mekerong ML, Titabar ML, Golaghat Extn IIA ML, Golaghat Extn IIA (addl) ML, East Lakhibari Extn. ML, Kalyanpur ML are prospective with proven/to be proven hydrocarbons. The drilling of these wells will thus add to the economic growth of the country. District TotalArea Avg depth Mining Lease (SKM) Locations Proposed (m) Name Jorhat Borholla 32.12 10 Jorhat Titabor 10 10 Mekrang Jorhat 16 5 Golaghat Extn IIA (addl) Golaghat 61 11 2200 - Golaghat Extn IIA Golaghat 24 7 3300 East Lakhibari Extn. Golaghat 49 5 Kalyanpur Golaghat 40 5 2.2 Geological setting of the area: The proposed area of the mentioned ML is a part of the South Assam Shelf. The South Assam Shelf is a part of Assam & Assam-Arakan basin and situated in the Dhansiri valley separated from North Assam shelf by a major E-W trending Jorhat fault. The area represents a part of foreland basin flanked by NE-SW trending Naga Schuppen belt on the East & Southeast and Mikir Massif in the West. The area is sparsely exhibiting intra-cratonic graben filling sediments from Permian age to basaltic flows of Early Cretaceous age. The extensive Late Cretaceous- Oligocene sequence deposited in Passive margin setting witnessed differential erosion at places and overlain by a thick pile of Miocene to Recent sediments deposited in a foreland setting. The total sedimentary thickness in the area is of the order of 3500m. Reservoirs in different stratigraphic levels starting from fractured Basement to Sylhet, Kopili, Barail, Bokabil, Tipam and Namsang have been charged in different parts of the basin depending on entrapment and are required to be probed for hydrocarbons. 3.0 Technological aspects (drilling with layout, Cementing, Logging, Stimulation & Testing) 3.1 Drilling methodology For drilling of vertical section of the well Rotary Drilling, for drilling of well carrier mounted mobile drilling rig along with portable stores and rig materials are used. Well location / Depth 53 Locations 2200- 3300m No. of wells proposed Borholla - 10 Titabor - 10 Mekrang - 5 Golaghat Extn IIA (addl) - 11 Golaghat Extn IIA - 07 East Lakhibari Extn. - 05 Kalyanpur - 05 Duration of proposed Drilling 2-3 months for each well Qty. of drilling fluid. About 700 m³ for each well Qty. of cuttings, cu.m. 225 m³for each well Qty. of drlg. Waste water, cu.m. 1000 m³ for each well Distance of Block boundary from the On land Locations coast line Development plan in case of strike Production will be taken HC reserve (initial in place) 11.14 MMt OIIP(PD) Formation pressure 275-290 Ksc Test flaring, duration 1 to 3 days Flare Details: Confined to the oil pit Details of the drilling rig proposed to be deployed Type of rig Electrical Rig Drilling mud composition Water based Drilling Fluid Power generator type & nos. AC – SCR Type. (06 Nos.) Diesel consumption @ 6 m3 / Day per day for each well Qty. of fresh water requirement & 1000 m3. Transported from nearby source source through contractor Manpower on rig 25 per shift of 12 Hrs. Two shifts / day Material requirement & Mobilization From ONGC base in Jorhat/Nazira Details of solids handling system on rig Shale Shakers - 1200 GPM Capacity Desander – 1200 GPM Capacity Desilter – 1200 GPM Capacity Details of Sewage treatment facility, if Not applicable any Waste Pit availability & Size 30’ x 33’ x 5’ - 2 Nos.