Reservoir quality evaluation of the Farewell sandstone by integrating sedimentological and well log analysis in the Kupe South Field, Taranaki Basin-New Zealand

S. M. Talha Qadri,Ahmed K. Abd El-Aal,Md Aminul Islam,Mohamed Ragab Shalaby

doi:10.1007/s13202-020-01035-8

Abstract

The study used the sedimentological and well log-based petrophysical analysis to evaluate the Farewell sandstone, the reservoir formation within the Kupe South Field. The sedimentological analysis was based on the data sets from Kupe South-1 to 5 wells, comprising the grain size, permeability, porosity, the total cement concentrations, and imprints of diagenetic processes on the reservoir formation. Moreover, well log analysis was carried on the four wells namely Kupe South 1, 2, 5 and 7 wells for evaluating the parameters e.g., shale volume, total and effective porosity, water wetness and hydrocarbon saturation, which influence the reservoir quality. The results from the sedimentological analysis demonstrated that the Farewell sandstone is compositionally varying from feldspathic arenite to lithic arenite. The analysis also showed the presence of significant total porosity and permeability fluctuating between 10.2 and 26.2% and 0.43–1376 mD, respectively. The diagenetic processes revealed the presence of authigenic clay and carbonate obstructing the pore spaces along with the occurrence of well-connected secondary and hybrid pores which eventually improved the reservoir quality of the Farewell sandstone. The well log analysis showed the presence of low shale volume between 10.9 and 29%, very good total and effective porosity values ranging from 19 to 32.3% as well as from 17 to 27%, respectively. The water saturation ranged from 22.3 to 44.9% and a significant hydrocarbon saturation fluctuating from 55.1 to 77.7% was also observed. The well log analysis also indicated the existence of nine hydrocarbon-bearing zones. The integrated findings from sedimentological and well log analyses verified the Farewell sandstone as a good reservoir formation.

Highlights

The hydrocarbon exploration and field development procedures are rapidly shifting toward the investigation of complex geological settings (Islam et al 2020)
Various researchers have worked on the reservoir quality evaluation around the globe, by using multiple techniques i.e., structural, sedimentological, or petrophysical analyses
The research by Martin et al (1994), Griffin et al (2015), Higgs et al (2017) and Jumat et al 2018 evaluated the reservoir quality on a basin scale, whereas very few studies (e.g., Dong et al 2018; Shalaby et al 2020) have utilized the integrated analysis to establish the reservoir quality on a field scale within the Taranaki Basin, leaving behind an ample scope of conducting a detailed investigation using sedimentological and well log analyses to determine the reservoir quality of the Farewell Formation within the Kupe South Field

Summary

Introduction

The hydrocarbon exploration and field development procedures are rapidly shifting toward the investigation of complex geological settings (Islam et al 2020). The research by Martin et al (1994), Griffin et al (2015), Higgs et al (2017) and Jumat et al 2018 evaluated the reservoir quality on a basin scale, whereas very few studies (e.g., Dong et al 2018; Shalaby et al 2020) have utilized the integrated analysis to establish the reservoir quality on a field scale within the Taranaki Basin, leaving behind an ample scope of conducting a detailed investigation using sedimentological and well log analyses to determine the reservoir quality of the Farewell Formation within the Kupe South Field. The Farewell sandstones, in the study area, were deposited in a valley by a northward draining fluvial system, developed by the Manaia Fault system (Alotaby 2015)

Methodology

Results and discussion

Conclusions

Compliance with ethical standards