Abstract The advent of highly deviated or near-horizontal wells has revolutionized the oil and gas industry, enabling access to previously untapped reserves, enhancing production rates, and reducing costs and environmental impacts. These near- horizontal wells present significant challenges to well intervention operations using slickline or wireline conveyance methods due to complex wellbore geometries and increased friction forces during deployment, limiting the achievable depth of intervention. Innovative solutions have been effectively tested and implemented within the Niger-Delta and other areas to overcome conveyance limitations, further improving operational efficiencies in highly deviated well trajectories during well intervention operations, enhancing safety and cost- effectiveness, whilst reducing risk. A novel gravity-fed mechanical conveyance tool represents a paradigm shift in well intervention operations. Our engineered technology harnesses the force of gravity with automotive design characteristics to enhance mobility and further reduce friction during tool deployment. This development enables the smooth and controlled conveyance of slickline or wireline tools in highly deviated wells with up to 84° deviation without the need for electric wireline tractors, surpassing the limitations of traditional conveyance methods. This publication focuses on compelling case histories from the Niger- Delta and other regions, demonstrating the tool's effectiveness in redefining the application envelope for well interventions. This paper will further review the engineering processes adopted and design simulations that ensured the conveyance tool met its targets in each candidate well. The case histories highlighted successful applications in various well intervention scenarios, including logging, well evaluation, remedial operations, and production enhancement. A detailed analysis of operational procedures, tool performance, and achieved results provides valuable insights for operators and engineers working across several oil wells in the Niger-Delta and similar challenging environments.