We are a fast growing and dynamic team of OFS specialists

Partners, associates and consultants

Partner led, analyst empowered, network inspired
Strength and breadth in oilfield domain and consulting expertise


Andrew Paterson
Managing Partner

Andrew leads OFS Partners with a vision to deliver practical and profitable client outcomes by generating insight, while upholding OFS Partners’ core values of excellence, stewardship and integrity. 

Andrew was previously a limited partner of the KKR acquisition vehicle for Acteon Group Ltd – a leading portfolio of oilfield services companies. He spent just under five years working for the executive management team and held line management roles within the portfolio companies. At Acteon, Andrew built on the research and due diligence experience he had gained at Pragma Consulting by implementing recommendations and ideas, working with Acteon companies on a deep operational level and engaging with the market to win work. OFS Partners similarly seeks to go beyond good recommendations by delivering practical insight and partnering with clients to create value.

Before founding OFS Partners, Andrew was Head of Strategy for Infield (a Wood Mackenzie business), where he led the growth and development of Infield’s strategy consulting team. Prior to that, he advised the Carbon Trust’s Offshore Wind Accelerator. Andrew’s career began with work on drilling fluids at the BP Institute, with the commercial aim of improving drilling efficiency. He has worked across the Americas, Europe, the Middle East and Asia and lives in London with his wife and children.

Andrew holds an MA in Chemistry and an MSci in Fluid Dynamics, both from Cambridge University.



Andy Duncan

Andy comes from a uniquely well combined engineering and finance background. More than 20 years ago as a Chartered Mechanical Engineer, Andy specialised in rotating equipment and managed capex investment projects on Shell Brent Bravo, among other key production facilities, for AMEC in the North Sea. After spending 5 further years designing refinery process units for UOP, he completed an MBA and moved into banking where highlights included structuring upstream financings for RBS and Bank of America Merrill Lynch, and acting as global relationship manager for clients ranging from majors: Total, BG Group and ENI; to large independents, including: Tullow, Premier Oil and Cairn with Standard Chartered.


Mel Earp

Mel’s analytical abilities were honed at Markel International where through the lens of risk and insurance, she had to rapidly assess the viability of activities in the upstream and midstream sectors. She later worked for a boutique management consultancy specialising in risk, energy strategy and policy and delivered value to clients through modelling and forecasting. At Acteon, Mel enabled growth and change at 2H Offshore, Team and Conductor Installation Services before managing business development for LM Handling. Latterly, Mel has been proving her entrepreneurial flair in a couple of different ventures which adds depth to her consulting work.


Ralph Benson

Gaining seven years of M&A experience with EY (in Edinburgh, Aberdeen and London), Ralph covered several high-profile oilfield deals working with Wood Group / PSN, Fugro NV and Petrofac PLC among others. Later, working as a pacer in the KKR owned Acteon Group, he also translated this into frontline operational experience negotiating major commercial contracts and managing business growth into new regions. In terms of safeguarding value, Ralph has managed country exits and liquidations, post-acquisition cost cutting and value capture exercises. Alongside strategic, operational and change management experience, Ralph is a chartered accountant and works across the breadth of OFS Partners’ mandates.

Colin Johston bw.jpeg

Colin Johnston

Previously as VP of Helix, Colin was instrumental in developing the first dedicated well intervention semi-submersible vessel in the Gulf of Mexico. This grew to three vessels, and a total of six worldwide, during his 13 years of operations with Helix Energy Solutions Group.  He is a true subsea well operations expert covering intervention, drilling and completions (including surface BOP operations) as well as having a background in topside commissioning and land based cementing & well stimulation. Prior to Helix, he expanded coiled tubing drilling in Europe and the Americas with Baker Hughes. Colin is also a founding partner of SeaNation, a consultancy for both subsea operations support and market access worldwide. Since 2006, he has been a voting member of the API sub-committee for Subsea Production Equipment and has been involved with OTC and the SUT in chairman and support roles.  He lives in Houston and travels frequently to the UK.



A career spanning 20 years has seen Stuart working in operational roles in both Halliburton and Schlumberger before leading InterAct Activity Management Ltd for the Acteon Group, which delivered value to operators though well abandonment and integrity & completions operations. Clients included BP, Shell, ExxonMobil, ConocoPhillips, Premier and TAQA amongst many others. He subsequently became the Well Abandonment and Integrity Director for the SPD group (a Petrofac company) and has recently been leading well abandonment operations for Talisman-Sinopec Energy. Stuart is a Non-Executive Director of Decom North Sea and lives between Aberdeen and Norfolk.

Tom Selwood website.jpeg

Tom Selwood

Having worked for both PWC and EY, Tom has an extremely strong financial background. This is coupled with managing M&A for Aviva and latterly in his career leading commercial and BD activities for marine contracting operations. Tom brought together multi-operator decommissioning (well P&A) campaigns at Offshore Installation Services, where he led their commercial and business development functions, and was previously the Commercial Director for Red7 Marine Offshore Ltd. His international experience encompasses complex jurisdictions in Asia, the Middle East and Brazil.


Colin Williams

Colin has over 20 years experience in management development and training. Prior to founding Wescott Williams in 1997, he was an internal coach at EY and since then has served energy sector clients such as Centrica, British Gas, Acteon and Magma Global as well as prominent blue chip brands like Lloyds Banking Group, BT, AXA, Nationwide and Intel. His work has transformative impact at both the individual and organisational level. People are found at the heart of major business issues, but also at the core of solutions that lead to value creation and Colin supports OFS Partners in unlocking this potential with its clients.


Our analytical team is the engine behind development of our in-house IP and support specific client engagements as appropriate

OFS Advisors

Experts in their field who both support OFS Partners and can provide input to client engagements (at client request).  They are typically oilfield veterans with whom we have a long standing relationship.  We currently do not publish their identity, but are happy to discuss how specific advisors might add value on a case by case basis.