Injectivity in the Surat Basin, Queensland, Australia: Likelihood and Uncertainty Evaluation

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• 作者：A. Garnett ; S. Hurter ; N. Marmin ; P. Probst ; S. Gonzalez ; S. Guiton
• 关键词：Injectivity ; Surat ; Precipice ; Probabilistic ; Carbon Dioxide ; Confidence Levels
• 刊名：Energy Procedia
• 出版年：2013
• 出版时间：2013
• 年：2013
• 卷：37
• 期：Complete
• 页码：3747-3754
• 全文大小：408 K

文摘

In the context of pre-tenement application studies, Monte Carlo simulations of steady state (initial) CO₂ injectivity for the Precipice Sandstone in the Surat Basin have been used together with discrete dynamic models to assess injection rate uncertainty. Such uncertainty analyses are used to guide exploration work programs. This paper considers an analysis of steady state injection rates based on a modified form of Darcy's Law, using parameter probability probability density functions (PDF) for 4 different tenement areas. Uncertainty in absolute permeability and upscaled permeability (as seen in an injection well) typically accounted for around 70 % of variation in estimated steady-state injectivity. Uncertainty in gross thickness and net-to-gross ratio accounted for most of the remaining variation.

Due to changes in depositional setting and depth, the P50 initial injectivity estimates for the Precipice Sandstone varies by an order of magnitude from 0.2 to 2.4 megatonne per anum (Mt/a) across the 4 areas. P10/P90 ratios were between 10 and 20 and are indicative of the relative immaturity of the technical assessment. Concepts including several wells will likely be required for industrial scale, multi-Mt/a developments. Dynamic well testing specifically to determine compartmentalisation and heterogeneity and the departure from steady state will be essential in designing and costing any field development plan. Therefore such data will be essential in any exploration or appraisal program.