Lithological and Depositional Environmental Assay of HMU-Well Reservoir Sands, Offshore, Niger Delta Basin, Nigeria

Abstract

One hundred and seventy-seven ditch cutting samples were collected from HMU-Well, Niger Delta Basin, at intervals of 5715 to 8695ft which marks the total depth of the Well. The samples were subjected to sedimentological and heavy mineral analyses. Ten (10) depths of interest were selected for sedimentological analyses. The heavy minerals present include zircon, hornblende and glauconite. Pickett cross plots were integrated in the reservoir quality and depositional environment of sand bodies of the HMU-Well, Offshore, Niger Delta. Evaluated parameters include; storage properties (porosity and saturation) flow property (permeability) as well as reservoir heterogeneities. Results show that the sands are texturally and compositionally mature as a result of high quartz arenite present. In general, quartz composition ranged from 85.25% to 95.48% conforming to the sandstone maturity, sample nine (9) showed the highest quartz arenite value with 95.48%, sample ten (10) with 93.25% and sample three (3) with 93.10%. The porosity is good to very good with porosity value of 9% to 11%. The sandstone bodies are sourced from mainly felsic igneous rocks and from low to high grade metamorphic rocks. The depositional system is fluvial while, the depositional environment is coastal plain. The reservoir quality of HMU-Well, is good and will yield optimal output on production.