Parihaka Reservoir Characterization by Integrating Well and Seismic Data through Seismic Inversion and Multiattribute Analysis

Abstract

A geophysical study to understand and Identify Pliocene - Pleistocene channels system and improve better understand of the channel geometry, fill lithology and connectivity and Generate rock property volume, Enhance reservoir quality, Hydrocarbon distribution and sweet spot detection with min. risk in Miocene reservoir (Moki formation). The Taranaki Basin is the only New Zealand basin to produce commercial quantities of hydrocarbons and still being underexplored. The Parihaka field is on the north-western Taranaki Peninsula located along the west coast of New Zealand's North Island (Veritas, 2005) which there only dry hole drilled based on 2D lines (Arawa-1). Moki formation is our main reservoir its depositional environment is turbiditic fan complex. Hydrocarbons are yet to be commercially produced from the Moki Formation on onshore Taranaki, (Smale et al., 1999). There was AVO study called "Investigation of the Miocene Moki Formation Within the Parahaki 3D Survey; Taranaki Basin, Offshore New Zealand Using Some Geophysical Tools" in Moki reservoir to Investigate and assess the AVO response of the Moki sand formation. By using the results of The AVO study, the inversion can apply in the area to enhance the result, generate rock property volume, Enhance reservoir quality, Hydrocarbon distribution and sweet spot detection with min. risk. By running three volumes of post stack inversion (vp, vs, density) and use λ, μ and vp/vs to identify the hydrocarbon contact distribution. Then by using AVO Inversion (Another different fast technic in the relative domain) to prove the results and using Extend Elastic Impedance Method. The result of this study is there are three prospects in Moki formation, the maps show that Arawa -1 at very low probability of hydrocarbon content which provide our result as it is a dry hole. By using multi-Attribute analysis, we can find new channels system in Pliocene age. Depending on the complexity of the channel system, different attribute analyses had varying success with each system. By using 3D curvature, variance and RMS Amplitude we can improve understanding of the Pliocene channel elements in terms of structure, channel evolution, and lithology. Based on the previous results for these channel systems, RMS amplitude and sweetness attributes can use to detect lithological changes that highlight both shale and sand dominant regions of the channel. These results suggest that the lithology of the small channel is refer to the delta lithology in this individuals channel area, and we can interpret the small channel is filled with a sand lithology, which allows the RMS and sweetness to detect in against the mud rich background lithology.