Effects of injection well operation conditions on CO₂ storage capacity in deep saline aquifers

Abstract

For large-scale CO 2 geological storage (CGS) in deep saline aquifers, storing maximum possible amounts of CO 2 over the project period is desirable. The ultimate storage capacity of a potential storage site is evidently a function of the static formation characteristics (e.g., formation porosity and thickness). However, it can be dramatically changed by the injectivity variations caused by the dynamic practices utilized during CO 2 injection. Proper management of a CGS project implies operating the injection well at the optimal well operating condition or injection scheme that ensure optimal injectivity and hence improved ultimate storage capacity. Practically, the operating condition of the injection well is partly controlled by the amount of CO 2 supplied by the emission source (e.g., power plant), which results in inevitable fluctuations/shut-downs during the operation. In this work, we investigate the effect of different operating conditions of the injection well on the injectivity and the ultimate storage capacity of the aquifer. With CO 2 injected continuously or intermittently, constant terminal-rate and constant terminal-pressure well operating conditions are studied. Next, we provide a simple net-present value (NPV) analysis to evaluate the economic feasibility of adopting different injection schemes. The results are applied to a synthetic CGS project with injection history to investigate their implications. Finally, we present a sensitivity analysis to test the effect of varying the injection rate, the vertical permeability, and the formation dip angle on the dynamic storage capacity.

Analysis of Vertical Permeability and Its Influence on CO2 Enhanced Oil Recovery and Storage in a Carbonate Reservoir

“…For the influence of k z on CO 2 storage, Abdelaal et al (2021) studied the effect of the k z /k x ratio on ultimate CO 2 storage capacities in a saline aquifer undergoing CO 2 injection. Our result (Fig.…”

“…A considerable number of studies have focused on the influence of k z on flow prediction. Unfortunately, most flow simulations that consider k z typically treated the k z /k x ratio as a sensitivity parameter and examined its influence on defined metrics (e.g., Kerans et al 1994;Ren and Duncan 2021;Abdelaal et al 2021). Campero et al (2014) made an analysis of k z /k x based on the geological data sets collected in a field and evaluated the influence of k z /k x ratio on history match and prediction during waterflooding.…”

Paradigm for Determining the Optimal Ultradeep and Super‐thick Saline Aquifer for High‐TDS Mine Water Geological Storage

“…However, research on the reservoir's storage spatial characteristics in deep (burial depth more than 1000 m) and ultradeep (burial depth more than 2000 m) aquifer formations has been gradually increasing in recent years. For example, the ultradeep and super-thick saline aquifers in this study were used as Liujiagou reservoirs for high-TDS mine water and CO 2 storage (Zhao X L et al, 2017;Abdelaal et al, 2021). However, the permeability and porosity of ultradeep reservoirs are generally difficult to study through in situ tests.…”

Effects of Injection Temperature and Pressure on CO2 Storage Capacity and Safety in a Sloping Formation

“…As a result, the cumulative amount of CO 2 to be stored in the formation decreases, with a larger extent updip and smaller downdip. 25 Ahmadinia 26 found that increasing the dip angle increased the buoyancy of CO 2 , resulting in more space for injected CO 2 to migrate upward, with a larger migration distance and interaction with more formation water. Wang 27,28 and Jing 29,30 found that formation dip angle had a certain impact on CGS.…”

“…The extent of the injected CO 2 plume is not the same on both sides of the injection well in a sloping formation because injection in sloping formations causes an asymmetric distribution of the CO 2 plume. As a result, the cumulative amount of CO 2 to be stored in the formation decreases, with a larger extent updip and smaller downdip . Ahmadinia found that increasing the dip angle increased the buoyancy of CO 2 , resulting in more space for injected CO 2 to migrate upward, with a larger migration distance and interaction with more formation water.…”