By ENITAN ABEL JOHNGOLD ORHERUATA, mnipr

Petroleum Engineering Professor champions local materials, technological innovation and sustainable solutions in high-temperature oil-well cementing

In a compelling demonstration of the power of research to address practical industrial challenges, Engr. Prof. Patricia Nneka Onwuachi-Iheagwara has called for greater reliance on indigenous Nigerian materials and home-grown technological solutions in the petroleum industry.

Delivering her inaugural lecture at Southern Delta University (SDU), Ozoro, on 21, July 2026, the Professor of Petroleum Engineering explored an important challenge confronting modern oil and gas operations in her lecture titled “From Earth to Wellbore: Confronting Cement Retrogression in HTHP Wells with Indigenous Additives.”

The lecture examined how locally sourced materials, particularly selected Nigerian river sands, could provide an effective alternative to imported silica flour used in oil-well cementing operations under high-temperature and high-pressure (HTHP) conditions.

At the heart of her presentation was a fundamental question: why should Nigeria continue to depend so heavily on imported industrial materials when some of the resources required to develop local alternatives are available within the country?

Addressing a critical challenge in petroleum engineering

Prof. Onwuachi-Iheagwara explained that well cementing is essential to the safe and efficient operation of oil and gas wells. The process involves pumping a cement slurry into the space between the steel casing and the surrounding geological formation to provide zonal isolation and prevent the unwanted movement of oil, gas and water between formations.

However, as petroleum exploration moves into deeper formations, engineers increasingly encounter extreme temperatures and pressures that can compromise the integrity of conventional cement systems.

One major consequence is cement retrogression, a process characterised by declining compressive strength and increasing permeability of cement exposed to high-temperature conditions.

According to the professor, the transformation of cement hydration products under such conditions can weaken the cement sheath, potentially compromising zonal isolation and creating the risk of structural failure and unwanted fluid migration.

She noted that conventional industry practice involves adding approximately 35 to 40 per cent silica flour by weight of cement to improve the thermal stability of cement systems. While this approach has proved useful, dependence on imported materials raises concerns about foreign technology dependence, capital flight, procurement costs and the limited development of indigenous alternatives.

Turning Nigeria’s natural resources into industrial solutions

A major highlight of the inaugural lecture was the presentation of research into the suitability of indigenous Nigerian sands as substitutes for commercial silica flour.

The research investigated sand samples obtained from different locations, including the River Niger in Asaba, Benin, Oleh, Ughelli and the Ethiope River axis of Delta State.

The investigation focused on the chemical composition, mineralogical properties, particle size distribution and organic content of the samples to determine their suitability for high-temperature cementing applications.

The findings indicated that selected samples contained approximately 90 to 95 per cent silicon dioxide (SiO₂), an important component in the development of thermally stable cement systems.

The professor explained that the performance of locally sourced sand depends not simply on its availability but on appropriate processing. The material must be thoroughly washed to remove clay and other impurities, dried to reduce moisture content and finely milled to achieve the particle size required for effective performance.

These treatments are essential because untreated sand may adversely affect cement-slurry properties, including pumpability, setting time and the overall strength of the resulting cement sheath.

Encouraging results from laboratory investigations

One of the most encouraging aspects of the research was the reported performance of cement formulations containing properly processed indigenous sand.

In the laboratory results presented, a formulation using fully cleaned and washed sand achieved a compressive strength of approximately 2,100 psi after 24 hours, increasing progressively to 4,000 psi after 28 days under the reported high-temperature curing conditions.

The lecture also presented a substitution strategy involving partial and complete replacement of imported silica flour with indigenous sand.

The preliminary findings suggested that substitution levels of between 60 and 80 per cent using appropriately treated Ughelli sand were presently possible.

These results point towards a promising opportunity for reducing dependence on imported silica flour while encouraging the development of local materials-processing capacity.

Prof. Onwuachi-Iheagwara, however, emphasised the importance of further performance evaluation, particularly in relation to the ability of indigenous additives to withstand demanding downhole conditions and the need for consistent production at industrial scale.

Research, sustainability and the circular economy

Beyond its technical implications, the lecture placed considerable emphasis on the economic and environmental benefits of indigenous innovation.

The professor described the approach as a low-cost circular solution that could replace imported industrial inputs with locally available resources.

By utilising suitable river sands and developing local processing capabilities, Nigeria could reduce international transportation requirements, import-related expenses and dependence on foreign supply chains.

The approach also offers an opportunity to create additional value from indigenous natural resources while promoting research partnerships between universities, industry and local manufacturers.

For the Niger Delta, a region whose economic fortunes are closely connected to petroleum exploration and production, such innovations could contribute to the development of a stronger local oilfield services industry.

The message was clear: the future of Nigeria’s petroleum industry must involve not only the extraction of natural resources but also the development of indigenous knowledge, technology and industrial capacity.

A distinguished academic and professional journey

The significance of the inaugural lecture is further underscored by the distinguished academic and professional journey of its presenter.

Prof. Patricia Nneka Onwuachi-Iheagwara began her academic career with a Bachelor of Science degree in Geology from the University of Ilorin. She subsequently obtained postgraduate qualifications in Petroleum Engineering from the University of Benin, Mechanical Engineering from the University of Nigeria, Nsukka, and Petroleum Engineering from the University of Port Harcourt.

In her commitment to developing her teaching and educational skills, she also obtained a Postgraduate Diploma in Education from Usmanu Danfodiyo University, Sokoto, before earning her PhD in Petroleum Engineering from the University of Benin.

Her professional experience has spanned different sectors, including aviation, non-governmental organisations and the oil servicing industry, before her eventual transition into academia.

She began her academic career at Delta State University, Abraka, where she distinguished herself as the first female substantive Associate Professor of Petroleum Engineering at the university’s Oleh campus.

She also served as Acting Head of the Department of Petroleum and Gas Engineering on two occasions and subsequently became the pioneer Acting Head of the Department of Petroleum Engineering following the restructuring of the former Department of Chemical and Petroleum Engineering.

Her contributions to university administration extended to several other responsibilities, including course advising, examination administration, faculty representation and service on various university committees.

Following her transfer to the Delta State University of Science and Technology, Ozoro, she eventually joined Southern Delta University, where she holds the distinction of being its first female substantive Professor of Petroleum Engineering.

She is affiliated with several professional bodies, including the Nigerian Society of Engineers, Society of Petroleum Engineers, Nigerian Association of Petroleum Explorationists, Nigerian Mining and Geosciences Society, Nigerian Institute of Industrial Engineers and the Association of Professional Women Engineers of Nigeria. She is also registered with the Council for the Regulation of Engineering in Nigeria, the Council of Mining Engineers and Geoscientists, and the Teachers Registration Council of Nigeria.

An enduring message for the university and the nation

The inaugural lecture was more than an academic presentation on cement chemistry and petroleum engineering. It was a strong argument for the relevance of university research to national development.

It demonstrated how scientific investigation can identify opportunities within Nigeria’s natural resources and transform them into practical solutions for industrial challenges.

For Southern Delta University, the lecture represents an important contribution to its commitment to scholarship, innovation, scientific inquiry and service to society.

For Nigeria, it reinforces the need to invest in indigenous research, strengthen collaboration between academia and industry, and encourage the commercial development of technologies arising from local scientific discoveries.

Prof. Onwuachi-Iheagwara’s research offers an encouraging direction for the petroleum industry: one in which locally available resources can become valuable industrial inputs, university research can inform field applications, and technological innovation can contribute to economic independence.

Ultimately, the journey from earth to wellbore is not merely about finding suitable sand beneath Nigerian soil. It is about recognising the value of what the country already possesses and applying knowledge, creativity and engineering expertise to turn those resources into solutions.

It is a timely reminder that some of the answers to Nigeria’s industrial challenges may lie not in what the country imports, but in what its researchers can discover, develop and deliver from home.