Curie depth and heat flow analysis of Ikot Ekpene and environs, Eastern Niger Delta Basin, using airborne magnetic data

Uche Iduma,Stephen Stephen Onyejiuwaka,Nwokeabia Charity Nkiru

doi:10.14419/ijag.v8i2.31186

Abstract

Aeromagnetic dataset over Ikot Ekpene and environs, Eastern Niger Delta Basin, was processed to compute the basement depth, Curie isotherm depth, geothermal gradient and heat flow within the area in order to investigate the depth to magnetic sources, geothermal prospect and the hydrocarbon potential of the place. The adopted computational method transformed the spatial data into frequency domain and provided a relationship between radially average power spectrum of the magnetic anomalies and the depths to respective sources.Â The results of the analysis showed that the depths to centroids and top boundaries range from 7.84 to 13.38 km and 0.233 to 0.459 km respectively. Curie depths within the basin undulate and vary between 15.42 and 26.49 km. The geothermal gradients range between 20.758 and 35.649 â°C/km while the corresponding heat flow is about 51.896 mWmâ»Â² within east of Ikono, north of Mbak and west of Abak Areas and 89.124 mWmâ»Â² within Amawum, Ndoro, Isiala, Ogbuebule and east of Uyo Areas. Based on the computed sedimentary thicknesses, high geothermal gradients and delineated major faults and fractures which could serve as migratory pathway for hydrocarbon or hydrothermal fluid, some parts of the study area have been demarcated for geothermal prospect and detail hydrocarbon exploration.Â Â

Highlights

Lithospheric thermal gradients are rarely distributed uniformly and are sometimes contaminated by local thermal anomalies; they are often estimated from near-surface heat-flow measurements
This research is aimed at estimating the depth to magnetic sources and computing the Curie isotherm depth, geothermal gradient, heat flow and sedimentary thickness within Ikot Ekpene and its environs, in the Eastern Niger Delta Basin, South-south and South-east Nigeria, in order to investigate the geothermal prospect and the hydrocarbon potential of the area
The results suggest that Curie isotherm depths (Fig. 7) vary within the study area with minimum depths ranging from about 15.427 to 24.158 km at Amawum, Ndoro, Isiala, Ogbuebule, Nwaigwe and Abak Ukpum Areas; intermediate depths with range greater than 24.158 to about 25.14 km at Obot Akara, Nkuot Etok, Achan Ika, Ikot Apan and Mbak Areas; and maximum depths, greater than 25.14 km, at Ikot Ekpene, Nung Idio, east of Ikono, north of Mbak and west of Abak, Atani and Amayi Areas

Summary

Introduction

Lithospheric thermal gradients are rarely distributed uniformly and are sometimes contaminated by local thermal anomalies; they are often estimated from near-surface heat-flow measurements. This research is aimed at estimating the depth to magnetic sources and computing the Curie isotherm depth, geothermal gradient, heat flow and sedimentary thickness within Ikot Ekpene and its environs, in the Eastern Niger Delta Basin, South-south and South-east Nigeria, in order to investigate the geothermal prospect and the hydrocarbon potential of the area. This part of the Eastern Niger Delta Basin (study area), has in the past received limited attention in geophysical studies compared with other parts of the basin. Temperature inside the earth directly controls most of the geodynamic processes that are visible on the surface (Nwankwo et al 2011)

Objectives

Results

Conclusion