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2-brine-rock interaction at in-situ reservoir conditions and its implication for tight oil EOR
Published in Vladimir Litvinenko, Youth technical sessions proceedings, 2019
S.T. Wu, X.F. Zhai, H.W. Yu, Z.C. Yu, Z. Yang
Based on our results, changes in ion concentration and mineral transformation in the Chang 7 tight sandstone generally corresponded with each other, and mineral evolution including the dissolution, migration, and re-precipitation of clay minerals and the dissolution of feldspars and calcites, had remarkable effects on pore structure and seepage capacity. Generally, Ca2+ is affected by the dissolution and secondary precipitation of calcium-bearing minerals such as calcite and calcium montmorillonite. During the early stage of the experiment, acidic water entered the system and diluted the original water, resulting in a reduction in pH, the dissolution of calcite, and an increase in Ca2+ concentration. As the experiment continued, Ca2+ concentration continued to increase and combined with other ions to form calcium montmorillonite, leading to a decrease in Ca2+ concentration. Mg2+ is affected mainly by the dissolution and secondary precipitation of magnesium-bearing minerals such as chlorite and montmorillonite. During the early stage of the experiment, the concentration of Mg2+ increased with the dissolution of chlorite. During the late stage of the experiment, chlorite was being dissolved continuously, and montmorillonite was precipitated. There was only a slight change in Mg2+ concentration through the experiment because Mg2+ was being both produced and consumed.
Effect of ionic solutions on clay mineral crystal chemistry
Published in C. Di Maio, T. Hueckel, B. Loret, Chemo-Mechanical Coupling in Clays, 2018
M.F. Brigatti, L. Poppi, L. Medici
Documentation of the diagenetic changes in clay minerals with increased burial in a sedimentary basin describes a series of prograde reactions that commonly define the clay mineral evolution of the basin or of the sedimentary sequence. These chemical and min-eralogical changes can provide a record of thermal history where reaction progress may correspond to a semi-quantitative measure of temperature or degree of thermal maturity.
Geometallurgical characterisation of a Channel Iron Deposit (CID) Ore
Published in Mineral Processing and Extractive Metallurgy, 2022
Huibin Li, D. J. Pinson, P. Zulli, L. Lu, R. J. Longbottom, S. J. Chew, B. J. Monaghan, G. Zhang
Some important reactions happen during the heating process, such as dehydration of goethite and hydrohematite phases, and decomposition of hematite, which affects mineral evolution. Figure 1 shows the thermogravimetric analysis - differential scanning calorimetry (TGA-DSC) curves of hematite Ore A and goethite Ore B in air and nitrogen. Both Ore A and Ore B were pre-dried at 105°C for 12 h before testing to ensure the moisture was totally removed, which is the reason why there were no weight loss before 100°C in Figure 1(a) and (b). The moisture contents of Ore A and Ore B were 4.10% and 8.62%, respectively. Figure 1(a) shows that decomposition of hematite occurred from 1215°C in nitrogen and 1377°C in air, observed as an associated weight loss. Notably, there was a phase transition of hematite from type I to II at about 680°C (Chase 1996), as shown in the DSC curve of Ore A. Figure 1(b) shows that dehydration of goethite Ore B commenced at approximately 260°C and finished at approximately 400°C, and correspondingly the sample weight sharply decreased within this temperature range, which corresponds to the reported loss on ignition of the ore. The decomposition of hematite in Ore B occurred from 1142°C in nitrogen and 1350°C in air, which are lower than the corresponding decomposition temperatures of hematite ores.
Characterization of gasification-coke prepared with coal by-product and a high ratio of low-rank coal addition
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Fanhui Guo, Jianjun Wu, Yixin Zhang, Kang Hou, Lixiang Jiang
Major minerals in coal and mineral evolution behaviors during pyrolysis have been widely studied (Cheng et al. 2010; Ogorman and Walker 1973), but few researchers study the mineral evolution in coking process of gasification-coke. The changes of mineral species under the high-temperature conditions of the coking process are known to be associated with ash-related issues and coke property during stationary application (Kerkkonen, Mattila, and Heiniemi 1996). In this study, we mainly study the evolution of mineral species in gasification-coke coking process. Figure 3 shows the XRD pattern of the coke produced from 1373 K and the ratio of MC is 0%, 10%, and 20%. H, Ky, Mu, Ol, S (SiC), T, and Q represent the minerals hematite, kyanite, mullite, oldhamite, silicon carbide, troilite, and quartz, respectively.
The effect of diagenetic environment on hydrocarbon generation based on diagenetic mineral assemblage in mudstone
Published in Petroleum Science and Technology, 2018
Jiazong Du, Jingong Cai, Guoli Wang, Xiang Zeng, Yujin Bao, Fei Liu
The concentrations of different diagenetic minerals vary at different burial depths (Figure 5); thus, several diagenetic mineral assemblages can be distinguished accordingly, and the changes in the diagenetic environment will be investigated. As the diagenetic minerals are the result of the diagenetic environment, the content will change correspondingly when the diagenetic environment changes. What needs emphasizing is that the more intensely the diagenetic environment changes, the faster the mineral content changes. Therefore, the diagenetic mineral content change rate (CCR) (content change rate = content variation/depth variation) was introduced in order to reflect the turning point of the diagenetic mineral evolution and the diagenetic environment. The change in the CCR can more intuitively reflect a change in the mineral evolution and the diagenetic environment. A large CCR indicates that the diagenetic environment changes rapidly and vice versa. The results showed that the CCR of smectite/I-S, illite, and kaolinite is high at 2,000 m, and the CCR of smectite/I-S, illite, chlorite, and ankerite is high at 3,000 m (Figure 5). Therefore, the diagenetic evolution process can be divided into three stages according to the CCR. Stage I (1,000–2,000 m): smectite/I-S content showed an obvious high value (78%) and less fluctuation, and illite, kaolinite, chlorite and ankerite content was low (less than 10%). Stage II (2,000–3,000 m): smectite/I-S content decreased (59%) while illite content increased slightly, and kaolinite content increased obviously (2–88%, averaged 14%). Stage III (>3,000 m): smectite/I-S content was further decreased (39%), while illite, chlorite and ankerite content increased, and kaolinite content is low (7%) (Table 1). Therefore, three diagenetic mineral assemblages can be distinguished from shallow to deep: I. Smectite/I-S; II. Smectite/I-S + illite + kaolinite; and III. Smectite/I-S + illite + chlorite + ankerite.