Detection of High-Potential Oil and Gas Fields Using Normalized Full Gradient of Gravity Anomalies: A Case Study in the Tabas Basin, Eastern Iran

Abstract

The normalized full gradient (NFG) represents the full gradient of the gravity anomaly at a point divided by the average of the full gradient at the same point. The NFG minimum between two maxima in an NFG section or a closed minimum surrounded by closed maxima on an NFG map may indicate density-deficient anomalies closely related to possible oil-gas reservoirs. On a cross-section, closed minima can be used to estimate the depth to centers of possible hydrocarbon reservoirs. The NFG map can also be used to locate oil-gas exploratory wells for estimation of the depth of possible reservoirs. The objective of this paper is to use two and three-dimensional (2D and 3D) NFG on gravity data of the Tabas basin in Yazd province, eastern Iran. A hypothetical model is first considered to explore the NFG characteristics and their relationship with the geometry of the model. The physical properties of the model are then studied to simplify the interpretation of real data. Finally 2D and 3D NFG models are developed for real gravity data to predict the location of any possible high potential oil-gas reservoirs. The results obtained indicate two zones in the northern and central parts of the Tabas basin suitable for hydrocarbon prospecting. However, the favorable zone located in the middle of the basin in which anticline E is detected at a depth of 5-7 km is more important for the purpose of hydrocarbon exploration.

Interpretation of gravity anomalies to delineate some structural features of Biga and Gelibolu peninsulas, and their surroundings (north-west Turkey)

“…The NFG technique was first used for exploring oil reservoirs (Berezkin, 1967;Berezkin & Buketov, 1965) and then used for various investigations (e.g. Aghajani, Moradzadeh, & Zeng, 2011;Ekinci & Yiğitbaş, 2012a, 2012bOruç & Keskinsezer, 2008b;Zeng et al, 2002). The normalisation procedure in NFG computation helps to minimise the strong field perturbation associated with downward continuation of the potential field data (Aghajani et al, 2011).…”

“…Aghajani, Moradzadeh, & Zeng, 2011;Ekinci & Yiğitbaş, 2012a, 2012bOruç & Keskinsezer, 2008b;Zeng et al, 2002). The normalisation procedure in NFG computation helps to minimise the strong field perturbation associated with downward continuation of the potential field data (Aghajani et al, 2011). Application of NFG technique typically enhances the anomalies by computing the anomaly to a level close to the source bodies and (Oruç & Keskinsezer, 2008b).…”

A geophysical approach to the igneous rocks in the Biga Peninsula (NW Turkey) based on airborne magnetic anomalies: geological implications

“…The technique was first used for exploring oil reservoirs (Berezkin, 1967;Berezkin & Buketov, 1965) and then used for many investigations (e.g. Aghajani, Moradzadeh, & Zeng, 2011;Oruç & Keskinsezer, 2008;Zeng et al, 2002). The normalization procedure in NFG computation helps to minimize the strong field perturbation associated with downward continuation of the potential field data (Aghajani et al, 2011).…”

“…Aghajani, Moradzadeh, & Zeng, 2011;Oruç & Keskinsezer, 2008;Zeng et al, 2002). The normalization procedure in NFG computation helps to minimize the strong field perturbation associated with downward continuation of the potential field data (Aghajani et al, 2011). Application of NFG technique usually enhances the anomalies by computing the anomaly to a level close to the source bodies and may point to the boundaries of the causative bodies (Oruç & Keskinsezer, 2008).…”

Estimating the location of a causative body from a self-potential anomaly using 2D and 3D normalized full gradient and Euler deconvolution

“…It integrates the analytical signal and the downward continuation. This method has been widely used to interpret 2D potential field data (Hou and Shi, 1986;Ebrahimzadeh Ardestani, 2004;Dondurur, 2005;Aydın, 2007Aydın, , 2010Oruç and Keskinsezer, 2008;Sındırgı et al, 2008;Aghajani et al, 2009Aghajani et al, , 2011Fedi and Florio, 2011;Zhou, 2015).…”