• Energy Research
• 2016-2025close

Abstract Organic compounds with functional groups susceptible to hydrolysis hold the potential to become thermo-sensitive tracers. To broaden the range of available compound classes for typical temperatures encountered in low enthalpy geothermal reservoirs, the group of carbamates was investigated. The kinetic parameters of eight primary and one secondary carbamate(s) were studied by means of isothermal batch experiments. The influence of several parameters on hydrolysis kinetics was investigated, which included the compound structure, temperature, and pH/pOH. The results demonstrate the possible application of these tracers within a broad range of temperatures.

Abstract Heletz, Israel is the location for an onshore deep saline CO 2 storage pilot site. The ‘ Heletz sandstone ’ is the building unit of the deep saline reservoir. Based on core samples of sandstone and caprock taken from the newly drilled injection (H18A) and monitoring wells (H18B), this article examines and reports the petrophysical properties of the Heletz Formation reservoir important for the short and long term trapping of CO 2 . A suite of laboratory and pore-scale CT-based modeling techniques are employed to determine the flow and transport parameters used by the continuum-scale numerical simulators and the mineral composition necessary for the understanding of mineral trapping processes. The effect of diagenesis on the reservoir parameters was determined in the laboratory using sedimentological, petrological, and petrophysical analyses. Variations in 87 Sr/ 86 Sr isotope composition and fluid inclusion analysis bring additional information about the diagenetic development and define the status quo of fluid–mineral reactions before CO 2 injection. Cathodoluminescence microscopy and SEM/XRD revealed the amounts of minerals in the sandstone samples and caprock and explained the poor binding of the sandstone which may lead to mobilized material during injection. Digital image analysis on thin sections, cathodoluminescence, and SEM were integrated with attributes derived from mercury intrusion porosimetry, steady state gas permeametry or nuclear magnetic resonance to form an essential outline for the Heletz Formation reservoir. This relates storage space, injectivity and storage efficiency to features such as grain size, pore size distribution, effective porosity, intrinsic permeability, or tortuosity. Furthermore, the laboratory and numerical CT-based investigation techniques are compared and discussed. The benefit of combining experimental methods and numerical simulations on pore-scale models is the increase in confidence of the parameter accuracy, fundamental for the success of the planned activities at Heletz.