Oil and Natural Gas Corporation Limited
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OIL AND NATURAL GAS CORPORATION LIMITED EIA for the Development of Vashishta and S-1 Fields of KG Offshore, Expansion of Odalarevu Onshore Terminal and Installation of Sub-Sea Pipeline, East Godavari District, Andhra Pradesh Executive Summary - Final Asian Consulting Engineers Private Limited, New Delhi DECEMBER 2013 EIA report for Development of Vashishta and S-1 fields, expansion of Odalarevu onshore processing terminal and installation of dual 14” sub-sea pipeline EXECUTIVE SUMMARY 1. INTRODUCTION Project Highlights Oil & Natural Gas Corporation Limited (ONGC), a premier Govt. of India Undertaking and the major National Oil Company, is a vertically integrated company producing crude oil, natural gas and value added products like LPG, NGL, Petrol, HSD etc. Operations of ONGC extend over both onshore as well as offshore within India and outside India. ONGC intends to drill and complete four wells in Vashishta and S-1 fields off the East Coast of India. The approximate distance of Vashishta and S-1 fields from Amalapuram coast is 26 to 35 km. As the development of these fields entails the entire spectrum of activities from drilling to production and setting up of facilities, various options were analyzed by internationally reputed integrated consultant (M/s Pegasus International) for each of the major components of the facilities i.e. Drilling & Completion, Subsea System & Controls, Well Fluid Pipelines (offshore & onshore) up to Onshore Terminal at Odalarevu and Onshore Terminal Facilities and the development scheme / field development plan was firmed up. Based on the details of the CAPEX (accuracy +25%) indicated by the Integrated Consultant in its report, the total capital cost of the project (including marine survey, consultancy, PMC, TPI, service tax, etc.) for the development of Vashishta and S-1 fields works (including expansion of onshore terminal and installation of dual sub-sea pipeline) out to be USD 724.93 million (inclusive of survey and project management/consultancy services). Based on the aggregated OPEX per annum estimated by Integrated Consultant, the operating expenditure including service tax has been worked out as USD 18.03 million per annum. Objective and Scope of EIA study The Objective of EIA study is to meet the regulatory environmental clearance criteria as well as to ascertain a sustainable development through the assessment of likely impacts due to project related activities on the surrounding environment. The study envisages likely assessment of negative impacts and alleviation of these negative impacts, to such extent that it avoids/mitigates any harm/ permanent changes in the naturally existing environment. As TOR for expansion of existing Onshore Terminal, also includes studies to be conducted in respect of offshore drilling and laying of Pipelines from Offshore to Onshore Terminal, the report contains three volumes (Vol-I, Vol-II and Vol-III), each catering to expansion of onshore terminal, offshore drilling and pipeline laying respectively. The scope of the EIA study includes detailed characterization of the existing status of the terrestrial, marine and socio-economic environment within the study area, identification of the potential environmental impacts of the project, and formulation of an effective Environmental Management Plan (EMP) to prevent, control & mitigate the adverse environmental impacts, and ensuring the environmental compliance. Apart from suggesting mitigation measures to the negative impacts, the report suggests implementation of various positive and enhancement measures as a part of project benefit program to people of the nearby areas. This report is based on the TOR approved by Ministry of Environment and Forests, Government of India vide letter- No. J-11011/591/2012-IA II (I) dated 4th June, 2012. Asian Consulting Engineers Pvt. Ltd. 1 EIA report for Development of Vashishta and S-1 fields, expansion of Odalarevu onshore processing terminal and installation of dual 14” sub-sea pipeline 2. PROJECT DESCRIPTION ONGC intends to drill & complete two wells in Vashishta field and re-enter & complete two wells in S-1 field off the East coast of India in water depths ranging between 250-700m. As part of development of these fields, ONGC also plans to develop following facilities: a) Sub-sea tieback of these 4 wells to shore with 14” dual pipeline through a daisy chain architecture, with suitable sub-sea facilities including subsea control units and umbilical. b) Expansion of onshore terminal at Odalarevu to handle VA & S-1 well fluids, along with sharing some of the facilities of G-1 and GS-15 terminal which is under construction. The salient features of the project have been summarized in the following table: Name of the Project : Integrated Development of Vashishta & S1 fields - drilling & completion of four wells in Vashishta & S-1 fields, installation of dual sub-sea pipeline and expansion of onshore terminal at Odalarevu Location / site alternatives : Vashishta and S-1 fields, KG Offshore, East Godavari under consideration district, Andhra Pradesh Number of Existing Wells Five wells (G1-9, G1-10, G1-11, G1-DA, G1-DB) Total number of proposed : 4 wells - VA-DA, VA-DB, SI-A and S1-B Production Wells Type of hydrocarbon : Gas expected Expected hydrocarbon gain : Average daily gas rate of 5.75 MMSCMD (for a period of five years) has been envisaged from Vashishta and S-1 Field. The cumulative gas production at the end of nine years is expected to be close to 15.775 BCM. Target Depth of the drilling : 2200 m True Vertical Depth Subsea wells Type of the rig to be used : Semi-submersible Drilling Rig/ Drillship Proposed Drilling Fluid for : Water-based drilling fluid system each well Anticipated Volume of Drill : 300 - 400 m3 Cuttings for each well Existing Pipeline Facility Dual 10 inch sub-sea pipeline to evacuate production fluid from G-1 and G-15 fields to existing onshore terminal. Length: 25 km approx. Proposed Pipeline Facility : Dual 14 inch sub-sea pipeline to evacuate production fluid from Vashishta and S-1 Fields to Proposed Onshore Terminal. Length: 45 km approx. Onshore section of pipeline is approx. 4km Existing Terminal Capacity : 2.75 MMSCMD of gas & 1500 m³/d of crude (Under Construction) Proposed Capacity of the : 7.25 MMSCMD of gas & 1500 m³/d of crude Terminal after expansion Expected Cost of the Project : $724.93Million (INR 3407.17 crores @Rs. 47/$) Asian Consulting Engineers Pvt. Ltd. 2 EIA report for Development of Vashishta and S-1 fields, expansion of Odalarevu onshore processing terminal and installation of dual 14” sub-sea pipeline 3. DESCRIPTION OF THE ENVIRONMENT The study area comprises of both terrestrial and marine environment. The S-1 and Vashishta field falls in the Bay of Bengal off the eastern coast and the onshore terminal at Odalarevu is proposed to be expanded. The 14 inch dual subsea pipeline will evacuate the well fluids (mainly gas) from wells to the onshore terminal. The existing/ baseline environmental set-up of the study area has been studied during the months of September to November as described in following sub- headings. Geology & Topography Geologically the area is characterized by major NE-SW trending fault within Mio-Pliocene sequences. The northern boundary of the fault is same extension of Ponnamanda- Adavipalem fault. The onshore area is mostly surrounded by agricultural fields with general elevation of the study area about 10 to 15 m amsl. Seismic Consideration According to seismic-zoning map of India [IS 1893: 2002], the study region falls in Zone III of the seismic zones of India. Climate and Meteorology The climate is mainly governed by the presence of Bay of Bengal. The climate of the area is moderate and humid and the temperature ranges from 21 to 38 °C. The study area receives rainfall from the south-west as well as north-east monsoon. As per the agro-climatic zones of Andhra Pradesh, the study area falls in Godavari Zone. The average wind pattern shows predominant winds blowing from SW and NE. The calm wind (wind speed < 3.39 m/s) conditions prevailed for 3.80 % of the total time. Bathymetry and Sea-bed topography The proposed wells in S-1 and Vashishta field have water depth varying in the range between 250-700m. The continental shelf has a regular bathymetry with isobaths running parallel to the coast. Waves & Tides The maximum wave height (Hmax) in the area varied between 0.45 m to 4.40 m and the significant wave height (Hs) varied between 0.3 to 2.8 m at 90 m of water depth. The tides in this region are characterized as predominantly semi-diurnal. Depressions & Cyclones The study area due to its, physio-graphic and climatic conditions is one of the most disaster prone areas as it is vulnerable to windstorms and frequent severe cyclonic storms, which originates in the Bay of Bengal as low pressure zones. Circulation The dynamics of circulation near the study area is plain and even. During high tide the sea water enters the coastal plain and thereby the salinity level increases on the adjacent area. Casurina plantations are present for certain stretch of this coastline. Asian Consulting Engineers Pvt. Ltd. 3 EIA report for Development of Vashishta and S-1 fields, expansion of Odalarevu onshore processing terminal and installation of dual 14” sub-sea pipeline Land Use The land use within the study area has been studied and it can be broadly classified into seven major categories viz., plantation, mangrove, water, agriculture, aquaculture, fallow land and built up land. The land use distribution of the study area is given below in Table 1. Table 1: Land use distribution of the Study Area S. No. Land use Area (sq km) Percentage 1 Plantation 59.68 31.11 2 Mangrove 1.03 0.54 3 Water 13.61 7.09 4 Agriculture 52.93 27.59 5 Aquaculture 56.65 29.53 6 Built Up 3.36 1.75 7 Fallow Land 4.57 2.38 Total 191.81 100 Land Subsidence A writ petition filed by Krishna Godavari Delta Parirakshana Samithi, Bhimavaram, an NGO, on the issue of land subsidence in the Krishna-Godavari region due to exploration activities.