Our Consultants

James Black Director

Twenty three years experience in the oil industry, seventeen of which have been in a commercial role for various oil companies. Employed by Phillips Petroleum, BP and Chevron from 1985 to 1996. Became an independent commercial consultant to the oil industry in 1996 with extensive experience of the NNS and Sullom Voe plus unique cross-median experience.

Ashley Horobin Director

Twenty years experience in the oil industry, eighteen of which have been in a commercial role for various oil companies. Employed by Total from 1992 to 2000 and by Enterprise Oil from 2000 to 2002. Became an independent commercial consultant to the oil industry in 2002 and has worked extensively on gas projects and midstream transportation systems.

Steve Bibby Consultant

Over 33 years of oil and gas experience in the UK and Europe with major oil and gas producers, Texaco and Chevron. A proven track record of developing negotiating and renegotiating all types of oil and gas commercial arrangements across the value chain over more than 20 years. Became an independent commercial consultant in 2015.

Kwaku Boakye-Adjei Consultant

Fifteen years of UK and international upstream experience. Senior commercial and managerial roles at BG Group, RWE and Tullow Oil, rising to become Ghana Commercial and Economics Manager before joining Sigma in 2014. Currently working in the SNS and West Africa.

David Cass Consultant

Thirty five years technical, commercial and leadership experience in the oil industry. Eight years were in field operations with Schlumberger followed by twenty-five years in various roles within BP. Became a principal A&D consultant with Schlumberger Business Consulting in 2011 prior to joining Sigma as an independent commercial consultant in 2012. Specialist in strategy and planning.

Arpit Harbhajanka Consultant

Eleven years of experience in upstream oil & gas commercial and corporate finance roles, initially with BP. Became an independent consultant in 2015. Most recently worked on projects in the UK North Sea and West Africa.

Steve Highfield Consultant

Commercial Negotiator with over twenty five years UK and International oil industry experience working for various companies including new start-up companies, BG Group, Kerr-McGee and Melrose Resources. Joined Sigma in 2013 and has worked on access to infrastructure and M&A.

David Keating Consultant

Twenty nine years finance and commercial experience within the oil and gas industry all gained with BP. Posts held in Upstream, Downstream and Corporate Head Office. The last 15 years have all been spent in Upstream North Sea activity, both as accountant and commercial manager. Joined Sigma in 2008 and has deep knowledge of the NNS.

Brian McCleery Consultant

Wide ranging international oil and gas industry experience from 30 years with Shell, Gulf Canada, BG Group and as an independent consultant. Management roles in commercial, strategy, portfolio optimisation and investor relations complemented with an initial role in the industry as a drilling engineer.

Alex McFarlane Consultant

Eighteen years in the oil and gas industry with a background in economic analysis. Experience gained in Exploration, Development and Strategic Planning departments before becoming a commercial negotiator in 2000. Worked for Amerada Hess commercial department before becoming an independent consultant in 2003. Currently working in the SNS.

Christian Reyboz Consultant

Twenty five years experience in the oil and gas industry, 8 years in the subsea contracting industry and 17 in a commercial role, setting up and heading the commercial departments for Centrica Upstream and EnQuest. Started work as a consultant in 2017. Unique mix of knowledge and experience in the fields of commercial, legal, engineering and project management.

Andrew Sanders Consultant

Twenty years experience within the oil and gas industry, initially with Total. Joined Perenco in 2003, after an MBA, to manage the transfer of operatorship and the ongoing managment of commercial operations of the Bacton assets bought from BP. The portfolio was expanded in 2007 with the integration of purchases from ExxonMobil of the LAPS and Thames assets and the Easington/Dimlington and Wytch Farm assets from BP.

Sarah Trippier Consultant

Over 14 years’ experience in the legal profession including 6 years post qualified experience. After completing her Masters Sarah relocated to Aberdeen in 2013 to undertake an LLM in Oil and Gas Law. She has carried out a varied number of contracts with international private practice firms in Aberdeen and in-house with Operators supporting the commercial, joint venture, regulatory and litigation requirements of the businesses

Ajith Unni Consultant

Eight years experience in the upstream industry across the UK, Dutch & Norwegian North Sea. Economics & Commercial specialist with additional experience in asset & JV management. Held various roles with RWE Dea, INEOS and became a consultant in 2018 working on projects in the UK and the Middle East.

Richard Woollcombe Consultant

Thirty five years experience in the upstream oil & gas industry working as consultant since 2008 and, before that, with BP in a wide range of commercial and financial roles in the UK, Egypt and Indonesia. Most recently has been working on agreements for satellite fields and new developments in the UK and Norwegian sectors of the North Sea.