Sedimentological Analysis of Core Samples to Decipher Depositional Environments: A Case Study of ‘Valz-01’ Well Niger-Delta Basin, Nigeria

Abstract

Sedimentological studies of ninety-seven feet (97ft) of core, covering 1643 -1797.74 m from ‘Valz-01’ well Offshore Eastern Niger Delta was carried out using twenty-four (24) core slabbed samples with the aim of identifying the textural characterization of sediments from the various sectors of the lithologic unit and to determine the environment of deposition. Six lithofacies units were identified within the cored interval. They include: Muddy heterolith, laminated fine sandstone/siltstone, Fine sandstone/siltstone, Hummocky fine sandstone/siltstone, laminated shale sandy, and shale. Three depositional environments identified include marine environment, transitional and continental environment. The marine environment is characterized by the deposits of shale (1644.27 - 1709) m, while the continental environment is characterized by sandstone (1779 - 1781) m. The transitional environment is characterized by alternation of siltstone and shale (1643 – 1644.22 and 1781 – 1797.74) m. From the studies most of the analyzed samples are deposited in the delta influenced by fluvial and waves actions revealing beach sediments and turbidites.