Seismic expression and geomorphology of igneous bodies: A Taranaki Basin, New Zealand, case study

Abstract

Very little research has been done on volcanic rocks by the oil industry due to the misconception that these rocks cannot be "good reservoirs." However, in the past two decades, significant quantities of hydrocarbons have been produced from volcanic rocks in China, New Zealand, and Argentina. In frontier basins, volcanic piles are sometimes misinterpreted to be hydrocarbon anomalies and/or carbonate buildups. Unlike clastic and carbonate systems, the 3D seismic geomorphology of igneous systems is only partially documented. We have integrated 3D seismic data, well logs, well reports, core data, and clustering techniques such as self-organizing maps to map two distinct facies (pyroclastic and lava flows), within a Miocene submarine volcano in the Taranaki Basin, New Zealand. Three wells; Kora-1-3 drilled the pyroclastic facies within the volcano encountering evidence of a petroleum system, whereas the Kora-4 well drilled the lava-flow facies, which was barren of hydrocarbons. By integrating results from geochemistry and basin modeling reports prepared for Crown Mineral, New Zealand, we concluded that the reason that Kora-4 was dry was due to a lack of source chargenot to the absence of reservoir quality. Moreover, the Kora-1 well drilled a thick sequence (>1000 m) of pyroclastic flows in this submarine volcano by chance and found high peaks of gas in the mudlogs near the top 25 m of this sequence. A long-term test in this upper volcanic section resulted in 32 API oil flow of 668 barrels of oil per day for 254 ha result that challenges the misconception that volcanic rocks cannot be good reservoirs.

In-context interpretation: Avoiding pitfalls in misidentification of igneous bodies in seismic data

“…Furthermore, more than 90% of the documentation that does exist is focused on mafic intrusions (mainly sills), such." as those described by Planke et al (1999), Hansen and Cartwright (2006), Miles and Cartwright (2010), Klarner and Klarner (2012), Schofield et al (2017), Holford et al (2013), Jackson et al (2013), Alves et al (2015), Magee et al (2016), Cortez and Santos (2016), McLean et al (2017), Hafeez et al (2017), Gao et al, (2017), Schmiedel et al (2017), Infante-Paez and Marfurt (2017), and more recently by Rabbel et al (2018) and Infante-Paez (2018). Most of these studies focus on the mechanisms of magma emplacement into the sedimentary overburden, the associated deformation, and the magmatic plumbing system.…”

“…Although not extensively documented because they are not exploration objectives, the most common features related to igneous bodies seen in seismic data are intrusive sills (Planke et al, 1999;Hansen and Cartwright, 2006;Miles and Cartwright, 2010;Holford et al, 2012;Jackson et al, 2013;Alves et al, 2015;Cortez and Santos, 2016;Magee et al, 2016;Gao et al, 2017;Hafeez et al, 2017;Infante-Paez and Marfurt, 2017;McLean et al, 2017;Naviset et al, 2017;Schofield et al, 2017;Mark et al, 2018;Infante-Paez, 2018;C. K. Morley (personal communication, 2018); Rabbel et al, 2018).…”

“…The focus area of our study is in the Northern Graben of the Taranaki Basin, New Zealand. A summary of the tectonic history of this basin is described by Infante-Paez and Marfurt (2017). Although very extensive and complex, the evolution of the Taranaki Basin can be briefly summarized in three major phases of deformation: the (1) Cretaceous to Paleocene (approximately 84-55 Ma) extension, (2) Eocene to Recent (approximately 40-0 Ma) shortening, and (3) Late Miocene to Recent (approximately 12 Ma) extension (Giba et al, 2010).…”

Unsupervised seismic-facies classification using independent-component analysis

“…Depending on the seismic attribute that we choose, different information can be extracted (Infante-Paez and Marfurt, 2017) from the seismic volume, thus, relying on only one attribute information lead to an incomplete seismic interpretation. For this reason, multi-attribute techniques such as Principal Component Analysis (PCA), Selforganizing Maps (SOM) are commonly used.…”

Deeply buried ancient volcanoes control hydrocarbon migration in the South China Sea

“…Networks of igneous intrusions may thus potentially divert fluids (e.g., hydrocarbons) into and reactivate ancient, now-buried extrusive vents and volcanoes, allowing fluids to migrate upwards and bypass significant thicknesses of strata (Holford, Schofield, & Reynolds, 2017). Several studies document how extrusive and intrusive components of igneous systems can inhibit fluid flow and create traps (e.g., Schutter, 2003;Monreal, Villar, Baudino, Delpino, & Zencich, 2009;Gudmundsson & Løtveit, 2014;Infante-Paez & Marfurt, 2017). Understanding how igneous systems impact later fluid flow events is critical to de-risking the exploration and production of hydrocarbon, water, and geothermal resources (e.g., Babiker & Gudmundsson, 2004;Holford et al, 2017;Schofield et al, 2017;Wohletz & Heiken, 1992).…”