In connection with the Earnings call scheduled on August 13, 2026, please find attached the Earnings presentation.

Hindustan Oil Exploration Company Limited ‘Lakshmi Chambers’, 192, St. Mary’s Road, Alwarpet, Chennai - 600 018. INDIA. Phone: 91 (044) 66229000 ● Fax: 91 (044) 66229011 / 66229012 E-mail: contact@hoec.com ● Website: www.hoec.com CIN: L11100GJ1996PLC029880 August 13, 2026 By Online The Listing Department The Corporate Relationship Department National Stock Exchange of India Ltd., BSE Limited “Exchange Plaza”, Bandra Kurla Complex, 1st Floor, P. Jeejeebhoy Towers, Bandra (East), Mumbai – 400 051 Dalal Street, Mumbai – 400 001 Stock Code: HINDOILEXP Stock Code: 500186 Dear Sir / Madam, Sub: Earnings Call Q1 FY2026-27 – Presentation In continuation to our intimation dated August 10, 2026 and pursuant to Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015, the presentation of the Earnings Call of the Company for the Q1 FY2026-27 scheduled on August 13, 2026 is here with attached. The same is also available on website of the Company at https://hoec.com/earnings-call/. We request you to take the same on record. Yours Sincerely, For Hindustan Oil Exploration Company Limited Josephin Daisy Company Secretary & Compliance Officer Encl.: a/a Registered Office: ‘HOEC HOUSE’, Tandalja Road, Off Old Padra Road, Vadodara - 390 020. INDIA. Phone: 91 (0265) 2330766 ● E-mail: contact@hoec.com ● Website: www.hoec.com EARNINGS PRESENTATION Q1 FY27 | August 2026 Disclaimer No representation or warranty, express or implied, is made as to, and no reliance should be placed on, the fairness, accuracy, completeness or correctness of the information or opinions contained in this presentation. Such information and opinions are in all events not current after the date of this presentation. Certain statements made in this presentation may not be based on historical information or facts and may be "forward looking statements" based on the currently held beliefs and assumptions of the management of Hindustan Oil Exploration Company Limited (“Company” or “HOEC”) which are expressed in good faith and in their opinion reasonable, including those relating to the Company’s general business plans and strategy, its future financial condition and growth prospects and future developments in its industry and its competitive and regulatory environment. Forward-looking statements involve known and unknown risks, uncertainties and other factors, which may cause the actual results, financial condition, performance or achievements of the Company or industry results to differ materially from the results, financial condition, performance or achievements expressed or implied by such forward-looking statements, including future changes or developments in the Company’s business, its competitive environment and political, economic, legal and social conditions. Further, past performance is not necessarily indicative of future results. Given these risks, uncertainties and other factors, viewers of this presentation are cautioned not to place undue reliance on these forward-looking statements. The Company disclaims any obligation to update these forward-looking statements to reflect future events or developments. This presentation is for general information purposes only, without regard to any specific objectives, financial situations or informational needs of any particular person. This presentation does not constitute an offer or invitation to purchase or subscribe for any securities in any jurisdiction, including the United States. No part of it should form the basis of or be relied upon in connection with any investment decision or any contract or commitment to purchase or subscribe for any securities. None of our securities may be offered or sold in the United States, without registration under the U.S. Securities Act of 1933, as amended, or pursuant to an exemption from registration there from. This presentation is confidential and may not be copied or disseminated, in whole or in part, and in any manner. Page 2 AGENDA HOEC – At a Glance Asset-wise Updates `` Financials Glossary HOEC – At a Glance Q1FY27 at a Glance | Key Business Updates 1/2 Mumbai High: • B15: Preparation of Field Development Plan forDSF Block: B15 • B80 : Preparation for Workover job in D1 and D2 and drilling of 3 new wells is in progress. North East: • Kharsang: Workover carried out on 4 wells to increase production further after completion of 9 wells campaign in a single financial year. Oil production ramped up by 2x; higher gas potential than anticipated. Planning for next phase of drilling in progress. Rig Contract award imminent. • Dirok: Revised FDP has been approved extending the block; PSC extension under final review with DGH/MoPNG. HOEC team working closely with stakeholders to fast-track higher evacuation routes – includes providing vendor support for HOT TAPs. Cambay: Asset-wise Updates • PSC Extension of Block CB-ON/7 and signing of R2 area is awaited from MoPNG. • Installed Crude Oil Lifting Technology (COLT) for a pilot project to lift high viscous oil in well NB-11. Initial success – well has come on production. • Procurement of Sucker Rod Pump (SRP) system for Well SPD-1 is in progress. • Thermic Fluid Heater to handle the water cut during enhanced crude oil production in Palejfacility installed. This will increase production by 20% from the well. • Presently brine is knocked out and the main phase for lifting crude is expected to start mid August Cauvery: • Engaged SLB to revive gas production in PY1Earth-St2A by carrying out Rigless Well Intervention Job. Scope includes installation of velocity string and well clean up of the other two wells. Mid October target completion. Page 5 Q1FY27 at a Glance | Key Business Updates 2/2 Dispute with HPCL on Crude Sales • Sept 2026 | HPCL raised a dispute highlighting quality of crude oil sold; now on path of resolution • As sales revenue of ~INR 260 crore was held up due to the ongoing dispute, investments in our well drilling plans to ramp up production had to be deferred. • HPCL and HOEC agreed to cancel the invoice and sell to third parties. Sales ongoing. Other Updates • Production reduced from B80 due to high water cut on one well. Workover planned post monsoon. National Gas Grid Connectivity • Dirok Production continued at approximately 1/3rd of the production potential due to lack of full evacuation route. Discussions on going with stakeholders to increase capacity of the evacuation pipelines. Page 6 Asset-wise Updates Offshore | B80 The Block at a Glance Basin • Mumbai High • On the west coast of India, at Location a distance of ~110 km from Mumbai City Participating Interest • 100% JV Partners (if any) • None Q1FY27 Production • 605 BOEPD Reserves (July 1, 2026) • 35.48 MMBOE Regime • DSF Page 8 Offshore | B80 - Key Business Updates 1. HPCL – HOEC Crude Offtake & Resolution Status Background ▪ In Aug 2025, HOEC supplied ~417,000 barrels of crude oil to HPCL. Following processing of the cargo, HPCL raised concerns regarding the presence of organic chlorides in the crude stream o The matter relates to a single cargo event and discussions are ongoing between both parties Current Status ▪ HOEC has agreed to cancel the invoice of sale to HPCL and resell the same oil to third parties. ▪ Oil sale is in progress. Complete quantity anticipated to be sold off by end October/early November 2026. ▪ The Company continues to focus on: o Production optimization by planning workover on two existing wells in B80 o De-bottlenecking the offshore facility to increase production. o Reduce operating expenses by cutting down on diesel use for running equipment offshore. HOEC remains committed to a transparent, technically grounded and commercially balanced resolution with HPCL while continuing to maximize value from the B-80 asset Page 9 Offshore | B80 - Key Business Updates ▪ Drilling Plan Updates: Drilling Plan Overview o Workover of 2 existing subsea wells targeted in Q3FY27 post which drilling of 3 new wells to be done in Q4FY27 [Showing first 8,000 characters — download PDF for full document]