Multi-Attribute Analysis Using Coherency and Ant-Tracking Techniques for Fault and Fracture Detection in La Florida Anticline, Llanos Foothills, Colombia

Abstract

We present techniques to reduce noise and enhance seismic quality, making possible the first multi-attribute analysis of a 3D seismic volume in the Llanos Foothills (La Florida anticline) of Colombia using coherency and ant-tracking techniques for fault and fracture detection. The results could help reduce risk in models of reservoir fracture porosity and permeability. The dominant fracture strike direction in the studied seismic volume (La Florida anticline) is NE–SW (055 ± 20°), parallel to the structural strike of the adjacent Eastern Cordillera Foothills. The application of the ant-tracking technique also reveals the NE-SW fracture set for the reservoir rocks in the La Florida anticline as well as in the non-folded reservoir rocks to the SE. We compared the fracture intensity and orientation in folded rocks with the fracture intensity and orientation in non-folded rocks. Our study showed NE-SW, NW-SE, and E-W fracture orientations in the non-folded seismic volume, suggesting that regional stresses could produce these fracture sets, not just folding processes as previously proposed. The NW-SE and WNW-ESE fracture sets are only found in the Guayabo Formation (11 Ma–Present). A right–lateral strike–slip displacement on the nearby Algeciras fault system in the last 2 m.y. may have generated WNW-ESE and NW-SE Riedel-type shear fractures in the study area.

Advanced seismic characterization of a geothermal carbonate reservoir – Insight into the structure and diagenesis of a reservoir in the German Molasse Basin

“…Several studies have shown the applicability of 3D seismic data for fracture analysis (Jaglan et al, 2015;Fang et al, 2017;Albesher et al, 2020;Boersma et al, 2020;Loza Espejel et al, 2020;Méndez et al, 2020), which can be used to address the often-raised question of scalability of reservoir properties (e.g. Lake & Srinivasan, 2004;Li et al, 2019), i.e., can information regarding fracture properties be transferred from the well scale to the seismic scale and vice versa?…”

“…Furthermore, Wang et al (2016) used seismic attributes to describe the reef growth and the evolution of channel systems for Eocene carbonates in the Sirte Basin in Libya. Edge-or discontinuity detection attributes, like variance and chaos, have been used to conduct a small-scale seismic-based fracture analysis (Jaglan et al, 2015;Williams et al, 2017;Albesher et al, 2020;Boersma et al, 2020;Loza Espejel et al, 2020). Nonetheless, seismic data lacks the high vertical resolution of well and outcrop data.…”

“…Nonetheless, seismic data lacks the high vertical resolution of well and outcrop data. Various studies have therefore attempted to show the benefits of a combined approach using both seismic and well data, in order to reduce the uncertainties of reservoir characterization (Toublanc et al, 2005;Fang et al, 2017;Albesher et al, 2020;Boersma et al, 2020;Méndez et al, 2020). Another aspect to consider is that manual interpretation of seismic data can be a very time-consuming task due to the high amount of data, which is why computational solutions, such as supervised and unsupervised neural networks have been increasingly used for seismic interpretation, pattern recognition, and lithology classification in recent years (Saggaf et al, 2003;Baaske et al, 2007;Bagheri & Riahi, 2015;Roden et al, 2015;Brcković et al, 2017;Zahmatkesh et al, 2021).…”

“…And third, a seismic fracture orientation analysis (FOA) workflow is adapted, based on other studies (e.g. Albesher et al, 2020;Boersma et al, 2020), and applied to the 3D seismic dataset. The FOA results on seismic scale are compared with those at image log scale, in order to address the scalability of the FOA results.…”

Fault detection by skeleton extraction based on orientation field consistency

“…For the automatic extraction of fault lines and planes, ant tracking [10] can be used to extract fault lines based on curvature [11,12], chaos [13][14][15], and the coherence cube [16,17]. However, many parameters need to be considered for the ant tracking method, and adjustments to these parameters substantially affect the accuracy of fault detection.…”