Engineering Geotechnical Characterization for Pipeline Infrastructure: A Case Study of the Escravos–odidi Corridor in Niger Delta, Nigeria

Laying of Pipeline infrastructure in swampy deltaic terrain is often constrained by weak soils, shallow groundwater, and corrosive environments, yet few sitespecific datasets exist for tropical deltas. This study presents a comprehensive geotechnical investigation along the 40inch × 30 km Escravos–Odidi gas pipeline corridor in the Niger Delta, Nigeria. Thirty boreholes were advanced to 5.0 m depth, with systematic sampling and laboratory testing conducted to determine stratigraphy, index properties, moisture content, and soil chemistry. Results revealed a predominance of soft marine clays interbedded with occasional sand lenses. These soils exhibit high compressibility and plasticity (PI = 27–38%) and very high natural moisture contents exceeding 80%. Groundwater was consistently encountered at shallow depths (0–0.8 m), increasing the risks of trench instability and buoyancy effects. Soil pH values ranged from 5.8 to 6.8, indicating slightly corrosive to noncorrosive conditions with implications for cathodic protection. Based on the findings, the study recommends a minimum pipeline burial depth of 3.0m to mitigate settlement and uplift risks. Additionally, appropriate cathodic protection systems and soil improvement measures should be incorporated into design and construction. The study provides essential baseline data for pipeline engineering in swampy terrains and offers a framework for improving resilience, corrosion control and sustainable energy delivery in the Niger Delta and similar environments worldwide.