CO2 breakthrough experiments in a column packed with sand and filled with StimuFrac fluid or water to learn about transport of the stimuli (CO2) on environments where either water or the stimuli-responsive polymer aqueous solution (StimuFrac) is present. Results suggest co-injection of StimuFrac and CO2 as the potentially best alternative to deploy this novel fracking fluid.

Lab-scale stimulation was performed on Coso samples obtained from a single core (1623 feet TVD, reservoir Coso CGC 18-27) using StimuFrac and control fluid in the absence of stimuli-responsive polymer.

Lab-scale stimulation was performed on Coso samples obtained from a single core (1623 feet TVD, reservoir Coso CGC 18-27) using StimuFrac and control fluid in the absence of stimuli-responsive polymer.

A corrigendum was submitted to the journal of Geothermics on our article "Environmentally friendly, rheoreversible, hydraulic-fracturing fluids for enhanced geothermal systems" Shao et al Geothermics 58 (2015) 22-31. In the original article some permeability values were underestimated, in particular, for rock samples fractured by the stimuli-responsive fracking fluid (PAA-CO2). In addition, effective pressures were determined to be lower for three control experiments (deionized water-carbon dioxide, DIW-CO2). Therefore, we revised values of permeability and effective pressure as well as performed additional lab-scale stimulation experiments under identical conditions to further verify/update the deductions presented in the discussion section. This is the reason for the additional data introduced in the below Table 1 (grey color). The authors regret the following inadvertent errors and corresponding modifications. These modifications do not change the scientific conclusions of the article.

A corrigendum was submitted to the journal of Geothermics on our article "Environmentally friendly, rheoreversible, hydraulic-fracturing fluids for enhanced geothermal systems" Shao et al Geothermics 58 (2015) 22-31. In the original article some permeability values were underestimated, in particular, for rock samples fractured by the stimuli-responsive fracking fluid (PAA-CO2). In addition, effective pressures were determined to be lower for three control experiments (deionized water-carbon dioxide, DIW-CO2). Therefore, we revised values of permeability and effective pressure as well as performed additional lab-scale stimulation experiments under identical conditions to further verify/update the deductions presented in the discussion section. This is the reason for the additional data introduced in the below Table 1 (grey color). The authors regret the following inadvertent errors and corresponding modifications. These modifications do not change the scientific conclusions of the article.

Lab-scale stimulation work on non-porous fused silica (similar mechanical properties to igneous rock) was performed using pure water, pure CO2 and water/CO2 mixtures to compare back to back fracturing performance of these fluids with PNNL's StimuFrac.

This submission contains datasets and a final manuscript associated with a project simulating carbon dioxide push-pull into a conjugate fault system modeled after Dixie Valley- sensitivity analysis of significant parameters and uncertainty prediction by data-worth analysis. Datasets include: (1) Forward simulation runs of standard cases (push & pull phases), (2) Local sensitivity analyses (push & pull phases), and (3) Data-worth analysis (push & pull phases).

This submission contains datasets and a final manuscript associated with a project simulating carbon dioxide push-pull into a conjugate fault system modeled after Dixie Valley- sensitivity analysis of significant parameters and uncertainty prediction by data-worth analysis. Datasets include: (1) Forward simulation runs of standard cases (push & pull phases), (2) Local sensitivity analyses (push & pull phases), and (3) Data-worth analysis (push & pull phases).

Regional geological properties of sedimentary basins play a significant role in determining the safety of CO2 storage. Four major trapping mechanism have been identified: Structural and stratigraphic trapping is the containment of supercritical CO2 by low permeability / low porosity rocks and is the dominant mechanism during injection and initial storage phase. Residual or capillary trapping is the retention of supercritical CO2 in the pore space between grains and tends to be most relevant on a scale of tens to thousands of years. Solubility trapping is the uptake of CO2 into the formation water, which is considered to be the most important trapping mechanism over hundreds to millions of years (1). Mineral trapping leads to the permanent immobilization of carbon through the precipitation of carbonate minerals. This study assesses the conditions for solubility trapping in major Australian sedimentary basins. The total dissolved solid (TDS) concentration of the formation water has been compiled from over 900 wells as it, along with pressure and temperature, is a key variable controlling CO2 solubility and the associated change in fluid density. Fluid density is a critical factor in driving fluid advection which determines the rate of solubility trapping and downward migration in the formation. This process is vital in reducing the amount of highly mobile supercritical CO2 at the top of the formation and storing it as dissolved CO2 in deeper parts of the formation.