Chemo‐mechanical Alterations Induced From CO₂ Injection in Carbonate‐Cemented Sandstone: An Experimental Study at 71 °C and 29 MPa

Abstract

Carbon capture, utilization, and storage may lead to mechanical degradation of the subsurface reservoir from fluid‐rock interaction, which could lead to wellbore instability or reservoir compaction. To better understand potential relationship between mechanical degradation with various carbonate cement textures and compositions in sandstone reservoirs, six flow‐through experiments were conducted. Formation water (TDS = 5,390 mg/L) enriched with CO2 flowed through two types of Pennsylvanian Morrow B Sandstone: an ankerite‐siderite‐cemented sandstone (disseminated cement texture) and a calcite‐cemented sandstone (poikilotopic cement texture). The experiments produced little change in permeability in the ankerite‐siderite‐cemented sandstone, but permeability increased up to more than 1 order of magnitude in the calcite‐cemented sandstone. Ultrasonic measurements and cylinder‐splitting tests (also known as Brazilian tests) suggested negligible mechanical degradation of the ankerite‐siderite‐cemented sandstone. Variable changes, with significant mechanical degradation in the static moduli, were observed in the calcite‐cemented sandstone. Thus, dissolution of the disseminated ankerite‐siderite cement (0.28–0.30%) had minimal impact on modifying the flow network and the mechanical integrity of the sandstone, whereas dissolution of the poikilotopic calcite cement (0.89–1.13%, quantified with fluid chemistry and visualized with X‐ray microcomputed tomography) impacted the mechanical strength of the sandstone by disconnecting framework grains. With the high water‐to‐rock mass ratios (7.3–8.2) and number of pore volumes (147–675) employed in these experiments, potential risks are most relevant to regions near injection wells. Ultimately, the chemo‐mechanical effects induced by CO2 injection are strongly influenced by the cement texture and composition and the burial history of the reservoir rock.

Simulation study of chemo‐mechanical impacts of CO2injection in morrow b sandstone reservoir

“…Dissolution of calcite and chamosite (chlorite), especially at the beginning of the simulation, as indicated in Fig. 7, is corroborated by laboratory experiments on these and other reservoir rocks 58,59,60 …”

Control of Cement Timing, Mineralogy, and Texture on Hydro-chemo-mechanical Coupling from CO2 Injection into Sandstone: A Synthesis

“…Qualitative and quantitative microprobe analyses were conducted using carbonate standards on a Cameca SX100 (Madison, WI, USA) electron microprobe. Backscatter electron images and elemental composition of carbonate cements were captured and analyzed under the conditions described previously [38,40]. We used microprobe analysis to accurately differentiate the species of carbonate minerals (calcite, ankerite, and siderite), and to confirm that any chlorite present was iron-rich and thus more reactive.…”

“…This paper synthesizes the experimental results for multiple rock facies in Morrow B sandstone described in [37][38][39][40]. The HCM coupling experiments in the SWP project were designed and performed in two stages.…”

Field‐scale reactive transport assessment of CO2 storage in the Farnsworth unit through enhanced oil recovery practices

“…The injected CO 2 was originally derived from two major point source emitters, the Agrium fertilizer plant in northern Texas and the Arkalon ethanol plant in southwestern Kansas, 20 though since 2018 the CO 2 has only come from the Arkalon ethanol plant 21,22 . The southwest regional partnership on carbon sequestration (SWP), sponsored by the US Department of Energy (DOE), began a study on the FWU in 2012 involving laboratory experiments of CO 2 injection and transport, 23,24 characterization of the FWU pore fluids and geology, 25–29 numerical modeling of reservoir evolution resulting from CO 2 injection, 23,26,30–50 tracer studies, 41,51,52 and risk assessment and site monitoring 40,41,52–59 . Despite the extensive previous study, important knowledge gaps remain, especially with respect to larger‐scale chemical effects of the CO 2 injection beyond the vicinity of the injection and production wells.…”