Hilong Oil Service & Engineering Nigeria Limited ("Hilong") successfully completed an extremely challenging turnkey onshore workover and re-completion project in Nigeria. The well was characterized not only by ultra-high downhole pressure but also complex wellbore conditions and stringent operational constraints, making its technical challenges extremely rare on a global scale. Leveraging innovative technical solutions and outstanding engineering execution capabilities, the Hilong Nigeria team not only safely and efficiently achieved all operational objectives but also significantly shortened the project period by 17.7 days. This successful practice has not only set a new benchmark for top technical cases and records in Africa but has also earned the company widespread acclaim across the region, serving as a demonstration and testimony of the company's technical capabilities.
This operation was highly challenging from a technical perspective. Many companies, upon learning of the difficulties and risks involved, deemed it too challenging to attempt. Specific challenges including: the tubing parting above the subsurface safety valve, causing annulus-tubing communication, while high pressure was trapped below the safety valve flapper, creating a risk of it failing to open. During the actual kill operation, wellhead pressure reached as high as 4,600 psi, posing severe challenges to well control safety. The downhole packer had unseated due to the tubing failure, compromising its sealing effectiveness and increasing the difficulty and complexity of the kill operation. Moreover, the deformed tubing stump prevented the passage of conventional fishing tools, and limitations in local resources meant specialized tools requiring left-hand pipe were unavailable, severely constraining the design of the fishing plan.
Facing these challenges, Hilong's technical team demonstrated strong innovative and practical problem-solving capabilities. During the kill operation phase, the team, after multiple rounds of rigorous analysis, developed precise and comprehensive kill procedures, achieving a flawless first-time success. The team minimized losses by continuously monitoring fluid loss rates and dynamically optimizing the brine density, without relying on lost circulation materials. For the fishing operation, the team creatively adopted a customized tooling solution that included specially ordered large-bore slip-type overshots, windowed overshots for collar retrieval, and a combination of fishing tools including right-hand catch tools. This approach effectively overcame the limitations posed by the deformed fish top and restricted tool clearance, ensuring the successful completion of the fishing tasks while maintaining stringent well control throughout to guarantee downhole safety.
Concurrently, the headquarters, internal and external expert teams, and field crews collaborated closely. With technical confidence and a strong sense of responsibility toward the client, even before the project was fully launched, they conducted multiple rounds of technical solution reviews and communications, personnel mobilization, adaptability assessments of key equipment components for complex conditions, and subcontractor coordination. Adhering to high-standard HSE protocols and well control requirements, the team efficiently completed personnel training, equipment inspections, and other preparatory tasks. Their effective collaboration ensured the smooth progress of the entire operation. Through the collective efforts of the team, the project was delivered with speed and quality far exceeding expectations, presenting a satisfactory outcome to all parties.
A client representative commented in the project summary: "When confronting extremely complex technical challenges, the Hilong team exhibited top-tier professionalism and strong project management capabilities. Their expertise, dedication, and efficiency left a profound impression on us and greatly enhanced our perception of Hilong. We believe future cooperation will be even broader and deeper."
Fire tests gold, adversity tests men. The success of this onshore workover and re-completion project in Nigeria is not only a demonstration and validation of technical strength but also reflects outstanding management capability in complex local environments. This achievement holds profound significance: it has not only reinforced our technical and operational confidence but has also paved the way for the company's second growth curve.