Board of Directors
Dr. Tim Marchant
Chairman
Dr. Tim Marchant holds a Ph.D in Geology and has more than 35 years of senior executive experience in the oil and gas industry in Canada and internationally, with extensive experience in international operations and foreign growth strategies. In a career that spanned 29 years with Amoco and BP, he held senior executive positions in Canada and a number of countries in the Middle East including Egypt, Saudi Arabia, Abu Dhabi and Kuwait. Dr. Marchant is currently Adjunct Professor of Strategy and Energy Geopolitics at the Haskayne School of Business, University of Calgary. He also serves as a non-executive director of Vermilion Energy Inc. Dr. Marchant is also a member of the Institute of Corporate Directors and completed the ICD Directors Education Program in 2011.
Dr. Sean Guest
Director
Dr. Guest (Ph.D., Geology) has worked in the international oil and gas industry for over 30 years and is currently based in Singapore, at the heart of the energy-hungry Southeast Asia region. He led Valeura Energy’s transition from a small-cap Turkish gas producer of approximately 1,000 boe/d to become the largest independent operator of oil production in Thailand, with current production of more than 23,000 bbls/d and strong ongoing cash generation. Under his leadership, the Company attained the prestigious No. 1 position in the Globe and Mail’s 2025 ranking of Canada’s Top Growing Companies. Additionally in 2024, The Energy Council awarded Valeura the top energy company in the Asia-Pacific region and Dr. Guest as the top executive. Prior to spearheading the transition toward Southeast Asia, Dr. Guest oversaw Valeura’s operated gas exploration play in the Thrace basin, pursuing a deep, high-pressure/high-temperature basin-centered gas accumulation. Before joining Valeura, he was the CEO of two private junior companies, including Pexco Energy, a $700 million company that held production and exploration assets in the Australia-Asia region and East Africa. While running Pexco, he resided in Jakarta, Indonesia and oversaw the company’s first ever operated development and production from an oil field in Sumatra. Prior to his CEO roles, he worked in new business development and exploration for Woodside in Australia and Libya, and for Shell in the Netherlands, Australia, and Malaysia. His early career roles focussed on the “coal face” of the upstream industry, working with Schlumberger in Egypt.Education: B.Sc. Geological Engineering, Queen’s University, 1985; Ph.D. Geological Sciences, 1993.
Tim Chapman
Director
Tim Chapman is an international capital markets specialist residing in London with more than 30 years of experience spanning the globe. His career includes 25 years in investment banking roles with large financial institutions including JP Morgan Chase, CIBC World Markets, and finally RBC Capital Markets where he was head of international oil & gas. Mr. Chapman’s career has focused on corporate strategy and valuation, regularly providing expert advice to many companies on seminal M&A transactions and capital raises. His experience within the oil and gas sector is diverse, including upstream, downstream and oilfield services companies. In 2015, Mr. Chapman founded Geopoint Advisory Limited which provides independent advice to energy companies. He is also a director of certain Petrogas North Sea subsidiaries. Mr. Chapman started his professional life as a geologist and graduated from Earth Sciences at Oxford University.
Education: BA Honours Geology, Oxford University, St. Peters College, 1990
Russell Hiscock
Director
Russell Hiscock joined the Valeura board in January 2018 and is the past President and Chief Executive Officer of the CN Investment Division (Montreal), which manages one of the largest corporate pension funds in Canada. He has many years of equity portfolio management experience in both the Canadian and international stock markets, with particular emphasis on the oil and gas sector. He is a past Chairman of the Pension Investment Association of Canada (PIAC). Mr. Hiscock holds a Bachelor of Mathematics degree, a Master of Arts degree in Economics and an MBA. He is a Certified Chartered Financial Analyst and a Chartered Professional Accountant.
Anna Green
Director
Anna Green is a lawyer by background and has over 25 years of experience through a career focused squarely on the Asia Pacific region, primarily within the banking and technology sectors. She held increasingly senior roles with ANZ bank, including serving as the group’s Chief Risk Officer, and later as CEO for the bank in Laos and in the Philippines. Thereafter, Ms. Green transitioned to a technology-oriented career with Amazon, where she excelled at driving change through development of marketing, acquisition, and growth strategies. She was recognised for her successes as Asia IT Woman of the Year at the prestigious Women in IT Awards. In 2023 she joined the Toll Group, a leading global transportation and logistics provider, where she currently serves as Chief Enterprise Services Officer. Ms. Green is a passionate advocate for diversity and inclusion and is well-known for having partnered with the UN, regulatory and government bodies, as well as customers and business councils to build mechanisms that drive meaningful change.
Education: Bachelor of Laws, University of NSW; Bachelor of Arts (Political Science), Australia National University; Chief Executive Women scholarship at INSEAD.
Lina Lee
Director
Lina Lee was appointed as an independent director of Valeura effective August 1, 2023. Ms. Lee is a specialist in finance and energy, with over 25 years of experience in multiple industries and cultures, culminating in senior leadership positions at BP. She has held roles focused on rigorous portfolio management, financial management, business development, treasury and deal structuring, most recently serving as CFO & VP Strategy of BP’s Global Petrochemicals business. With considerable experience in developing and executing strategies focused on Asia, Europe, the Middle East, and Russia, Ms. Lee brings a wealth of international acumen and a strategic growth mindset, with a particular emphasis on executing inorganic growth transactions and business improvement initiatives. She is a Chartered Financial Analyst, educated in business.
Education: Bachelor of Business Administration (Honours), The Chinese University of Hong Kong, Hong Kong; Master of Business Administration, Kelley School of Business, Indiana University at Bloomington, U.S.A; Executive education, Harvard Business University, U.S.A.
Chalermchai Mahagitsiri
Director
Chalermchai Mahagitsiri was appointed as a director of Valeura in May 2025. Mr. Mahagitsiri is an entrepreneur engaged in various industries including energy, logistics, manufacturing, food and beverage, real estate, and the arts. He has led the Mahagitsiri family office into new markets, whilst enhancing strong governance and long-term value creation. Mr. Mahagitsiri has held leadership roles across several of his family’s businesses, including PM Group Co., Ltd., Posco-Thainox Public Company, Ltd., Lakewood Country Club Co., Ltd., and Quality Coffee Products Co., Ltd. Currently, Mr. Mahagitsiri serves as Executive Director, President and Chief Executive Office of Thoresen Thai Agencies Public Company Limited, and is also a member of the boards of Unique Mining Services Public Company Limited, PM Thoresen Asia Holdings Public Company Limited, Thai Future Incorporation Public Company Limited, and Mermaid Maritime Public Company Limited.
Education: Bachelor of Science in Accounting and Finance from Suffolk University; Master of Science in Economics and Finance from Boston University.
Joseph A. Tomkiewicz
Director
Mr. Tomkiewicz is a lawyer and energy law specialist with over 30 years of managerial, transactional, and litigation experience involving some of the world’s largest companies.
He is currently active in various board and executive capacities and serves as advisor on energy and legal issues. Mr. Tomkiewicz was previously a Partner and Co-Chair of the Energy Industry Team at Thailand’s oldest law firm, Tilleke & Gibbins. Prior to that, he served as general counsel, director, and officer of several Chevron Corporation affiliates, based in Bangkok, Thailand, and previously in Nigeria and Bangladesh. Earlier positions involved managing a 250-member team responsible for the merger of Exxon and Mobil, serving as Acting General Counsel at two of Mobil’s largest overseas affiliates in the middle east, as well as drafting, negotiating, and executing multi-billion dollar contracts on oil, gas, and chemical construction projects worldwide. His legal career has included managing a wide variety of litigated matters including antitrust, construction, copyright, exploration and producing, labour, maritime, marketing, patent, and tort law. Mr. Tomkiewicz currently serves as Sitting Director and Executive Committee member of the Association of International Energy Negotiators (“AIEN”) in Houston, Texas and is an Executive Committee member of The Future Energy Asia.
Education: LL.M. from Georgetown University, USA; J.D. from Yeshiva University’s Cardozo School of Law, USA; B.A. in French from the University of Wisconsin, USA.
