Influence of geostatistical interpolation method and cell-size resolution on CO2 storage capacity estimates: Application to saline aquifers with sparse data availability in Israel

Abstract

The primary focus for future large-scale projects targeting the sequestration of CO2 lies in underground saline aquifers. In southern Israel, two such aquifers were identified as suitable for CO2 storage, however, the data available for these aquifers is limited and sparse. To confront this challenge, geostatistical interpolation techniques are often used to fill in the data gaps. In this study, we evaluate the impact of the interpolation method and cell size on the storage capacity of these two saline aquifers. Eight interpolation techniques are used to estimate three parameters of the aquifers (thickness, depth, and porosity), which serve as the basis for evaluating the CO2 storage capacity, utilizing the US-DOE-NETL equation. Our findings show that the choice of the interpolation method and cell size has a significant impact on the calculated CO2 storage capacity, and therefore stress the importance of documenting these parameters. Our evaluation also shows that shallow CO2 storage sites exhibit a greater sensitivity to depth relative to deeper storage sites. The results of our study are applicable to early-stage assessments of regional CO2 storage capacity in which data is limited. Calculated CO2 storage capacities for the two aquifers indicate their continued suitability for CO2 sequestration in Israel.