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Geert Prins

Chief Executive Officer

Geert co-founded Well Services Group in 2005 and has more than 30 years of experience in the oil and gas industry. He has extensive experience in Well Intervention and prior to WSG held several international positions within NOWSCO and served as the General Manager Continental Europe position within BJ Services (now Baker Hughes). Geert holds a Master of Business Administration from University of Twente. As a founding owner of WSG, Geert’s focus on personnel development, equipment and process innovation, as well as delivering customer value has driven the growth of the business from initially a Netherlands based local company into an international operating integrated services company. Geert wants WSG to become “Best in Class” in the services offered around the globe.

Koos Frieling

Chief Technology Officer

Koos co-founded Well Services Group in 2005 and has more than 30 years of experience in the oil and gas industry. Prior to WSG, Koos held positions with Otis (Halliburton) and BJ Services (now Baker Hughes). Koos has a strong equipment and process knowledge and oversees our fleet globally to ensure all servicing and purchasing meets the required standards for our service delivery. He leads a number of initiatives, working with our clients to help us innovate and deliver additional efficiency and offer improved process safety.

Eric Witvoet

Chief Financial Officer

Eric joined Well Services Group again in April 2020, having previously been CFO between 2013 and 2017. He has experience internationally within Oil & Gas, Chemicals and the Bio-Fuels industry amongst others. He oversees Finance & Control, Cash Management, M&A and Legal Affairs throughout the group.

Andrew Burrell

Chief Operations Officer

Andrew joined Well Services Group in 2018. He was initially with Halliburton prior to becoming a Director/Owner of an Oil & Gas equipment rental company HSL, part of the OHS group of companies, providing equipment to well service and pipeline & process service companies globally. This business was acquired by Air Liquide in 2015. In 2016 Andrew formed ATAM Group in the UK, focused on new innovative processes for the Pipeline & Process market, a company that is now part of WSG. Andrew now oversees global operations and delivery of WSG’s group growth strategy in terms of geographic footprint and diversity of services.

John Guy


Joining the Well Services Group in October 2020, John is tasked with supporting WSG in its next phase of international growth expanding into new geographic territories and further increasing its service offering. John has 30 years of industry experience, most recently holding CEO position within EnerMech following a number of years as COO overseeing its international expansion. Prior to this John worked for PSL Energy Services and Halliburton, spending 4 years in the Caspian region and 13 years in the Asia Pacific market focusing upon growing businesses in the LNG and Oil & Gas pre-commissioning and mechanical services markets.

John Wingfield


Joining the Well Services Group in March 2021, John is tasked with supporting WSG in its next phase of international growth expanding into new geographic territories and further increasing its service offering. John has held a number of customer-focused senior management positions throughout over 30 years of industry experience. These include roles as BD Director for PSL Energy Services, UK Manager Production Enhancement for Halliburton, and BD Director / founding partner of Enermech.

Martijn Heemskerk

Business Unit Manager – Well Intervention Services

Martijn joined WSG in 2005 and has worked his way from field service positions through to his current role managing our Well Intervention division, consisting of Coiled Tubing Services, Slickline Services and Well Testing Services. Prior to his role with WSG, he was with BJ Services from 2000. Martijn takes ultimate responsibility for the safety critical, high quality service delivery we bring to our Well Intervention clients. He gives particular focus to personnel development and equipment optimisation along with efficient project engineering to ensure we maintain our reputation within Continental Europe.

Harry Schepers

General Manager Industrial Services – Continental Europe

Harry joined WSG in 2018 tasked with developing our Pipeline & Process Services/Industrial Services business within Continental Europe. His oil and gas career began in 1990 with positions in A.Hak Industrial Services and then BJ Services. From 2005 to 2018 Harry directed A.Hak Industrial Services European business. With his extensive market experience combined with WSG’s wide range of technical services and quality of delivery, Harry is rapidly driving WSG growth throughout Continental Europe.

Gareth Turner

Managing Director – UK

Gareth joined WSG in 2008, when he set up our first UK subsidiary offering Pipeline & Process Services. His Oil & Gas career began in 1993 with NOWSCO and Air Products where he specialised in onshore service delivery to improve the efficiency of customer turnaround events. Under Gareth’s management WSG has developed its position as a market leader in the UK onshore service market. Gareth has been the forefront of WSG’s drive to diversify its integrated service offering. From 2017-2020 he oversaw the move of WSG into offering Valve Services and Industrial Services through a series of successful acquisitions. As well as delivering our UK market growth Gareth has driven the WSG UK / Europe team through his extensive LNG experience to offering a number of innovative services developed to deliver value to both LNG construction and turnaround events worldwide.

William Tan

General Manager – Asia Pacific

William joined WSG in 2018 tasked with expanding our Pipeline & Process Services /Industrial Services business in South-East Asia. He previously developed the Asia regional business for IKM between 2006 and 2017. William is from a strong construction services delivery background in the region and brings this experience to WSG. This knowledge combined with WSG’s success and experience in refinery turnaround events and our strong local personnel skill base is driving the growth of our service offering throughout the region.