Contact Information

  • Akpevwen Onoyase


A highly experienced Petroleum Engineer (specialty in Reservoir Engineering) with over 18 years working in the oil and gas industry. I have proven track records of successful projects, leading and executing reservoir development plans. I also have in-dept understanding of reservoir engineering principles/processes and very knowledgeable in reservoir management/modeling, production engineering and well engineering. I am also very skilled in industry-wide software like Petroleum Experts, OFM, DCA, PEEP, ARIES, PHDwin , Petrel RE and programming language like python.

As a recipient of the much-coveted ExxonMobil Advanced Skill Milestone Awards (ASM) in both Reservoir Management and Reservoir Simulation, I have proven track record of my contributions to the industry, development of my peers and my contribution to the engineering profession.

Currently seeking for a technical leadership role in a value driven organization like yours to leverage my wealth of experience and my astute leadership skills to drive value for the realization of company’s goals and objective.






Strategic Deepdive Leader (Yoho/Inim Fields); ExxonMobil (Jan 2020 – Dec. 2022)
Led JV of the future Deep Dive Assessment for Yoho and Inim Assets increasing Asset NPV by >$900M
• Carried out situational analysis for both fields and framed strategic choices/value proposition that significantly improved JV cash generation through an integrated JV model
• Worked extensively with cross-functional teams to collaborate and resolve all integrated JV model complexities
• Developed materials for extensive multiple reviews with global company technical leadership to secure alignment
• Proposed strategic choices for both Assets integrated into the annual budgeting and planning for both fields

Senior Reservoir Engineer ExxonMobil (Jan. 2011 – Dec. 2019)
Lead Reservoir Surveillance Engineer (Joint Venture Shallow Water Fields)
Analytical Performance Prediction
• Carried out analytical prediction driven by opportunity generation, depletion planning studies, reserves revision proposals and long-term volume forecasting for annual budgeting cycle; tools used are DCA, MBAL and 3D simulation models
o Used DCA to determine high confidence remaining ultimate reserves as basis for our booked Proved Developed Reserves for Yoho, Awawa, Enang, Mfem, Eku and Oyot field (all shallow water fields)
o Updated historical production for 3D simulation models and used same to run predictions for both base wells and planned infills (new well drilling)
o Annual updates/calibration of Fields Production Platform IPM models to support long term production volume forecast for base wells and planned future drill wells
Reservoir Surveillance & Management
• Led and executed all reservoir surveillance activities like Annual Field Performance Review, Depletion Strategy Alignment Review, Wellbore Utility Review and all pressure data acquisition program to mitigate field oil production decline and maximize recovery; the overall impact of our robust surveillance best practices include:
o Mitigation of Yoho Field Annual Oil rate production decline to 5%; a significant improvement from the 14%–19% in prior years; this outstanding performance is the basis for my SPE Paper title “Achieving World Class Oil Recovery Factor through the Application of Integrated Reservoir Best Management Practices – The Yoho IB-1 Upper Reservoir Study”
Depletion Planning
• Led the depletion planning and strategy for different green fields with varying types of reservoir complexities, reservoir drive mechanisms and reservoir fluid types; Examples include:
o The Itut Field development as part of Satellite Field Development Program: investigated and recommended horizontal well development with natural depletion supported by gas lift (artificial lift); resulted in the approval of 8 new drill wells (EUR of 12MBO)
o The drill well assessment for the Yoho Area drilling program; Got AFE (Authorization for Expenditure) for 3 wells (total incremental EUR of 10 MBO)
o The Aran and Isuo Development as tie-back to Yoho Production Platform through extended reach drilling using the Integrated Reservoir Modeling and Simulation Software (IRMS), specifically designed for thin-oil column (resulted in approval for drilling of 6 wells; 4 wells in Isuo Field and 2 wells in Aran Field)
Opportunity Generation/Field Development
• Led several opportunity generation programs across different fields ranging from single infill drilling, workover for zone change/up-hole recompletion, assessment for artificial lift installation, program drilling and fieldwide redevelopment; examples are:
o The Awawa ZZ1 single well program in Awawa F4.0 reservoir to capture remaining recovery that will not be recovered by 2 existing wells (EUR of 4.0 MBO)
o The OML 104 drilling program with 7 new wells aimed at increasing Yoho asset oil production by > 15,000 barrel per day and also timely utilizing available ullage at the Yoho Production Platform before gas cap blowdown
o The low-cost restoration of shut-in low well-head pressure wells in the Yoho YB area through the implementation of gas lift (incremental recovery of 8MBO from 6 wells)
o Led the multifunctional team to develop the Field Development Plan for both Aran and isuo Fields and secured all required Regulatory approvals
Reservoir Simulation
• Built the Empower Simulation model for the Enang 1-RR2 reservoir with over 38 years of historical production; involved history matching for more than 70 wells; model prediction used to support Enang 1-RR2 re-development program (with six (6) new drill wells)
• Led the application of the IRMS (Integrated Reservoir Modeling and Simulation) modeling technique to thin oil column reservoirs in the Yoho Area (the Aran Field Study), resulting in the approval for funding for two new drill wells

Reservoir Engineer ExxonMobil (Sept. 2006 – Dec. 2010)
Reserves Lead/Coordinator
Stewarded the company’s quarterly reserves update and revision and reported to both internal and external stakeholders
• Timely planned and coordinated all required technical reviews
• Worked with cross-functional teams (Reservoir Engineers and Geoscientists) to implement all required recommendations form Senior Technical leaders.
• Led and supervised the processing of all required documentations to secure all required internal approvals.
• Prepared high level summary of quarterly changes and led clear and concise discussion with Senior Company leadership
• Timely prepared and reported all annual reserves revisions to all external stakeholders

Awards and Certifications

Advanced Skill Milestone (ASM) in Reservoir Management and Reservoir Simulation - ExxonMobil Technical Leadership Award

Post-Graduate Diploma in Data Science and Business Analytics


Reserves Assessment – Expert
• Depletion Planning - Expert
• Analytical Performance Prediction - Expert
• Reservoir Surveillance and Optimization – Expert
• Economic Analysis – Advanced
• Reservoir Description – Advanced
• Reservoir Simulation – Advanced
• Fluid Property – Advanced
• Reservoir Data Management – Competent
• Petrophysics – Competent
• Production Engineering – Competent
• Drill Well Assessment – Competent

Soft Skills
• Stakeholder Management
• Problem Solving
• Analytical Thinking
• Leadership
• Effective Communication
• Interpersonal Skills
• Collaboration
• Time Management
• Courage of Conviction
• Decision Making
• Research Skills
• Venture Mindset
• Self Starter


• Masters of Engineering in Petroleum Engineering
• Bachelor of Engineering in Petroleum Engineering