DC Geological Ltd
Darren Clark

Managing Director and Consultant Wellsite Geologist

I am an established and respected UK based independent Consultant Wellsite Geologist with over 25 years of experience in the Oil and Gas Industry working closely with various clients. DXC Geological was established in 2017 following a 16 year career as a Wellsite Geologist at Barrel Consultants Ltd working for various clients in the North Sea sector. If you are searching for a Wellsite Geologist for your upcoming drilling project or campaign, either in the UK North Sea or further afield, please take a look through my website and feel free to contact me with your requirements.

Baker Hughes


Consultant Wellsite Geologist

Barrel Consultants Ltd

September 2001 to December 2017


Director & Consultant Geologist

DXC Geological Ltd

January 2018 to Present

Barrel Consultants

The corrected d-exponent, also known as cd-exponent or more correctly dc-exponent as used in mud logging and formation pore pressure analysis in the oil industry, is an extrapolation of certain drilling parameters to estimate a pressure gradient for pore pressure evaluation while drilling. It is regarded as one of the best tools for pore pressure evaluation. "

DXC = log [(ROP / (60 x RPM)] / log [(12 x WOB) / (1000 x Diam)] x (initMW x actMW)

DXC Geological
Darren Clark

DXC Geological Ltd is covered by £10,000,000 Employers Liability, £5,000,000 Public Liability and £1,000,000 Professional Indemnity Insurances.

Printable PDF documents of all current and up to date certification, qualifications and other paperwork are available on the downloads page.

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•   Vantage Number 0137858

•   OGUK Offshore Medical, Expires July 2023

•   OGUK Further Offshore Emergency Training, Expires January 2027

•   OPITO Minimum Industry Safety Training (MIST), Expires January 2027

•   Escape Chute Training (Skyscape), Expires September 2023

•   Covid-19 Triple Vaccinated, December 2021

•   Sabre Panaseal FaceFit, June 2016

•   International Well Control Forum (IWCF) Level 1, Completed April 2016

•   Compressed Air Emergency Breathing System (CA-EBS), August 2014

•   DuPont Safety Training Observation Program (STOP), April 1997

•   Extended Reach Drilling (ERD) Course, Merlin, 2013

•   Drilling and Advanced Rig Training (DART) Course, 2013

•   Operations & Wellsite Geology Training, Stag Geological Services, 2001

•   PESGB Member since 2001

•   Geological Society Fellowship, 1999

•   Workplace Competency Assessor Course, D32/D33 S.Q.A., 1998

•   Pressure Evaluation Course, Baker Hughes Inteq, 1997

•   HPHT Course, BP Amoco, 1997

•   HPHT Training, Salos Sunesis, 2022

Data Engineer & Mudlogger

Baker Hughes Inteq

February 1995 to September 2001

Health and Safety Certification

Industry Related Training

Previous Employment History

DXC (Drilling Exponent)

Skills and Responsibilities

•   Wellsite responsibility for all geological, data engineering and formation evaluation activity, supervision and reporting.

•   Excellent knowledge of North Sea lithostratigraphy and highly experienced in exploration, appraisal and development wells in the Southern Gas Basin, Central & Viking Graben, Moray Firth and West of Shetlands.

•   Experienced in geosteered horizontal drilling through complex channel sands with the use of ultra deep resistivity tools such as Schlumberger GeoSphere and Baker Hughes VisiTrak.

•   Responsible for the selection of casing and coring points, XPT/MDT pressure and fluid sampling, sidewall core sampling points.

•   Experienced in Formation Pressure Whilst Drilling (FPWD) techniques with High Pressure / High Temperature (HPHT) knowledge and experience.

•   Responsible for conducting regular communications with onshore Drilling Operation team and liaising with offshore Drilling Supervisor and rigsite contractors.

•   Experienced in high angle extended reach (ERD) wells and their associated drilling techniques and formation evaluation.

•   Ensuring geological well objectives are met and any geological risks are identified, evaluated, managed and risk assessed.

•   Experienced in the use of oil based mud (OBM) and water based mud (WBM) systems.

•   Responsible for cuttings and show descriptions and end of well sample distribution and dispatch.

•   Experienced in conventional, aluminium and fibre-sleeved coring techniques, core handling and processing.

•   Experienced in conventional and TLC wireline logging and MWD/LWD FE acquisition, witnessing and quality control.

•   Computer literate, including use of offshore communications, geological and engineering database packages, log drawing packages (Geologix GeoSuite, RockWare WellCAD, HRH Gravitas Winlog) and standard PC applications.

•   Responsible for drafting wellsite geological Lithlog and proficient and very thorough in post well Composite well log and End of Well Report editing and preparation with a keen eye for detail.

•   Experienced in the evaluation and management of contractors performance including periodic reviews as required.

•   Confident in the use of the latest Heavy Mineral, Chemostratigraphy, Palynology and Biostratigraphy techniques.

•   Participation in well planning, DWOP, hole section preview and review meetings, daily conference rig calls, daily pre-tour meetings and rig safety meetings.

•   Participation in end of well review and wash-up meetings for lessons learned, highlights and lowlights for future well planning.

•   Responsible for wellsite data management, quality control and archiving and the compilation of final well data sets and distribution.

•   Excellent personal communications skills with firm professional confidence, diploma and highly team orientated.

Darren Neil Clark B.Sc., M.Sc., FGS


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