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With the continuous increase of shale gas production in China, the associated water production is also increasing, which is the mixture of the water used for hydraulic fracturing and the brine retained in shale formation. During the treatment of produced water, valuable elements such as lithium, potassium and bromine are further enriched and concentrated. especially lithium. resources, which has broad prospects for development and utilization, and can alleviate the contradiction between supply and demand of strategic resource lithium in China. In this paper, the shale gas resources in Sichuan are introduced and summarized mainly. And the ion content in the produced water of shale gas in Weiyuan and Changning areas in southern Sichuan is listed respectively. At present, the produced water volume of each well in Weiyuan and Changning is 19 800 m³ and 15 293 m³ respectively, and the lithium content in most of the produced water is 10, 62-58, 96 mg/L, which has high economic utilization value. The reserves and prospects of lithium resources in the produced water of shale gas are predicted. The applicability of extraction method, membrane separation method and adsorption method to the extraction of lithium in shale gas produced water are summarized, which provides the reference for the comprehensive utilization of lithium resources from shale gas formation in southern Sichuan. [ABSTRACT FROM AUTHOR]

The Tianbaoshan deposit, located in the Sichuan–Yunnan–Guizhou (SYG) metallogenetic belt, is one of famous Pb Zn deposits of Southwest China, with an established reserve of 2.6 Mt. Pb and Zn. According to the detailed field geological survey and microscopic petrography observation, three distinct ore fluid evolution stages can be divided. In this contribution, sphalerite and associated quartz from above diverse stages were carefully chosen for systematic fluid inclusion (FI) petrography, microthermometry, individual FI LA-ICP-MS analysis, Raman microspectroscopy, and in situ trace element investigation of sphalerite. The sphalerite only defines a two-phase aqueous FI type, while the FIs hosted in quartz exhibit diverse types, including two-phase aqueous FIs, vapor-rich FIs, and pure aqueous fluid inclusions. Our microthermometry results indicate that the homogenization temperature (Th) and salinity of FIs in sphalerite from the stage 1 are 109.6‐182.2 °C and 12.51–21.61 wt% NaCl equiv., respectively. The Th of the sphalerite-hosted fluid inclusions in stage 2 ranges from 97 to 158.3 °C, with a salinity range of 14.46–19.76 wt% NaCl equiv. The FIs trapped in sphalerite exhibited medium-high salinity and low Th, and Raman spectrum analysis shows that vapor composition of the FI is mainly H 2 O, reflecting the typical characteristics of basin brine. Measurements on quartz-hosted FIs yield homogenization temperatures from 134.3 to 233.1 °C, with a salinity from 4.49 to 12.62 wt% NaCl equiv. The gas phase composition of these inclusions is complex and consists of several components, such as CH 4 , N 2 , CO 2 , and H 2 O. The results indicate that the FIs present in quartz are dissimilar from those in sphalerite, and the sphalerite mineralization fluid has typical characteristics of basin brine and represents the ore-forming fluid. The significantly high Na and Ca of the mineralizing fluid is revealed, suggesting that the mineralizing fluid may be of the Na Ca system. Combined with Ca/K, K/Na and Rb/Na ratio, typical basinal brines origin was constrained by fluid composition analysis. The gradual enrichment of Ca, Mg, and Sr in the mineralizing fluid emphasizes the positive effect of fluid-rock reactions on the precipitation of Zn. The trace element in sphalerite of the Tianbaoshan deposit is distinct from SEDEX-, skarn-, and volcanogenic massive sulfide (VMS)-type deposits and notably similar to MVT deposits. Combining with fluid inclusion and sphalerite trace elements feature, we define the Tianbaoshan deposit as a typical MVT Pb Zn deposit. • Homogenization and freezing temperatures are similar to those of typical MVT brines. • Water-rock reactions play a positive role on the precipitation of Zn. • The ratios of K, Na, Cl, Br in ore-forming fluid also show the typical characteristics of basin brine. • The Tianbaoshan deposit is a typical MVT Pb Zn deposit. [ABSTRACT FROM AUTHOR]

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With the increasing number of shale gas wells being hydraulically fractured with recycled flowback and produced water to reduce the consumption of fresh water, geochemical indicators of hydraulic fracturing flowback fluids (HFFFs) from such wells need to be found to evaluate the potential pollutants caused by shale gas development. To fill this knowledge gap, we analysed 64 HFFF samples from 3 Changning wells (fracked with recycled wastewater) to form a time series and compared them to HFFF samples from 3 Weiyuan wells (fracked with fresh water). We also made comparisons of HFFFs from two types of wells in the Appalachian Basin with reported data. The results indicated that regardless of the fracturing fluid being used, the water‒rock reaction caused by the hydraulic fracturing process resulted in the release of exchangeable phase elements, such as lithium, boron, with relatively depleted δ7Li and δ 11B, and strontium with relatively enriched 87Sr/86Sr values on the shale surface, into the HFFFs. The composition of the injected fracturing fluid affected the strength of the water‒rock reaction, but the effect is negligible, as the fracturing process can still form the unique Sr, Li, and B isotope ratios of the HFFF. Thus, the elemental signatures (B/Cl and Sr/Cl) and isotopic fingerprints (δ 11B, δ7Li, and 87Sr/86Sr) derived from HFFFs can be used to distinguish between HFFFs from wells hydraulically fractured by either fresh water or recycled wastewater and flowback water from conventional oil and gas wells. The results are important for the environmental evaluation of the large number of wells being fracked with recycled wastewater each year. [Display omitted] • δ 11B and 87Sr/86Sr can be used as indicator for HFFF in Changning field. • Hydraulic fracturing caused the release of minerals enriched in 10B, 6Li, and 87Sr. • Shale formation water composition determined the ratio between Na, Ca, Cl, and Br. • Fracturing fluid composition impact the major elements of HFFFs in the first dozens of days. [ABSTRACT FROM AUTHOR]

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At present, the downhole technology of water reinjection wells in central Sichuan area can meet the requirement of produced water reinjection, but the phenomena of tube bundle break down, corrosion perforation and channeling leakage were exposed in the process of reinjection. The reinjection \veils that have been shut down due to corrosion accounted for more than 35 % of the shutdown wells. The corrosion evaluation result showed that the reinjection well casing in service in sulfur-containing block of central Sichuan was in moderate and serious corrosion, and the corrosion was intensified with the increase of temperature, showing local corrosion characteristics. Through the evaluation of corrosion inhibitor slubility and inhibition effect, the inhibitor CT2-19C was s elected and suitable for reinjection \veils in sulfur-containing blocks of central Sichuan area, the liquid-phase corrosion inhibition rate was more than 80%. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Resource-Richness Analogy Approach used in less explored reservoirs is proposed. • Genesis-Statistics Assessment Approach for heterogeneous tight oil is proposed. • The parameter criteria of lacustrine tight oil resource assessment are established. • In-place tight oil resources in China's major basins are estimated of 12.6 × 109 t. • 15 most favorable plays are outlined with in-place resources of 5.3 × 109 t. Large-scale commercial development of shale gas and tight oil resources in North American and continuous discoveries of tight oil in China lead to the recognition of the importance of assessment on tight oil resources. Based on the characteristics of China's tight oil reservoirs and exploration status, this paper discusses a workflow focusing on in-place resource evaluation. In the workflow, a Resource-Richness Analogy Approach (RR-AA) is proposed for assessment of tight oil resources in less explored areas, a Genesis-Statistics Assessment Approach (GS-AA) for lacustrine tight oil resources with strong heterogeneity and regions where more delicate assessment is required, and an EUR Analogy Approach (EUR-AA) for assessment on recoverable tight oil by fully using available EUR data of production wells. After analyzing the geological characteristics of the formation of tight oil in the Ordos, Bohai Bay, Songliao, Junggar, Sichuan and other major Basins, the distributions of essential parameters such as reservoir thickness, area and porosity have been defined, and the parameter evaluation criteria have been established. Finally, the tight oil resource potentials in the major basins in China have been evaluated using one of the three methods and the prospective areas of high resource abundance are outlined in each of basins. The results from this study show that China's tight oil resources have a large potential and good exploration future. The estimated in-place tight oil resources are 12.580 × 109 tons, mainly distributed in the Ordos, Songliao, Bohai Bay and Junggar Basins. 15 most favorable zones are proposed having in-place resources of 5.296 × 109 tons. [ABSTRACT FROM AUTHOR]

• Phase equilibria for ternary systems LiCl − LiBr − H 2 O and LiCl − LiBr − CH 3 OH at 298 K were performed. • The Pitzer model was engaged in predicting the solubility of two ternary systems. • The solubility modelling approach achieved a well agreement with experimental solubility. • The results support for surmounting the intractable problem of lithium enrichment in brine. Oil gas field brine is a dominant liquid mineral resource in Sichuan Basin, and its rational development and utilization is of great significance to the national economy. In order to explore the physicochemical properties of brine and provide theoretical guidance for the comprehensive utilization of brine, the isothermal solubilities of the ternary systems LiCl − LiBr − H 2 O and LiCl − LiBr − CH 3 OH at 298 K were determined by employing the isothermal dissolution equilibrium method. Based on the measured composition of the liquid phase, wet solid phase and equilibrium solid phase, isothermal phase diagrams of the two systems at 298 K were drawn. The results show that according to the phase diagram of the ternary system LiCl − LiBr − H 2 O at 298 K, there is no single salt and double salt formation, but the crystalline region precipitated by the solid solution occupies all the crystalline space. The phase region is divided by a solubility boundary line into two parts, namely the liquid phase unsaturated region located below the isotherm and the completely mutually soluble solid solution crystallization region above it. Therefore, the two single salts LiCl and LiBr could not be successfully separated with the guidance of this phase diagram. The ternary system LiCl − LiBr − CH 3 OH at 298 K has single salt and solid solution formed, but no double salt determined. The phase diagram of the ternary system LiCl − LiBr − CH 3 OH consists of an invariant point, two isothermal solubility lines, and two crystallization regions precipitated with Li(Cl, Br) and LiCl, respectively. Using the phase diagram as a guiding tool for phase separation, LiCl can be acquired by crystallization and filtration operations, but it cannot be achieved for LiBr. In this work, a combination of wet residue method and XRD is used to identify the equilibrium solid phase. Selecting the particle swarm optimization algorithm, the solubility predictions of the ternary systems LiCl − LiBr − H 2 O and LiCl − LiBr − CH 3 OH at 298 K were achieved through the well-established Pitzer model. The solubility simulation results satisfactorily matched with the experimental values, indicating that the parameters selected for the simulation have strong applicability. [ABSTRACT FROM AUTHOR]

The rapid growth of demand for lithium, especially in lithium batteries calls for an increase in the supply of lithium resources. We synthesized H 1.33 Mn 1.67 O 4 adsorbent by solid-phase reaction method to recover lithium for the first time from shale gas flowback and produced water (SGFPW) in the Sichuan Basin, China. Na 2 CO 3 precipitation pre-treatment was employed to improve the adsorption capacity and selectivity of lithium. The adsorption capacity of lithium in the pre-treated water (P-SGFPW) was 16.24 mg/g higher than that in SGFPW (13.27 mg/g), and the partition coefficient of Li+ increased from 731.58 to 1073.58 mL/g after precipitation. After four cycles of adsorption and desorption, the adsorption capacity of lithium was stable and showed only a slight decrease equal to 3.53% and 5.35% in P-SGFPW and SGFPW, respectively. H 1.33 Mn 1.67 O 4 is a promising adsorbent for lithium extraction from SGFPW, and precipitation before adsorption can improve its performance significantly. [Display omitted] [ABSTRACT FROM AUTHOR]

Superficial research on flowback and produced (FP) water from shale gas wells limit the targeted practice of corrosion protection and wastewater treatment. This study analyzes the injected fluid and the FP water at different stages in a single shale gas well with freshwater hydraulic fracturing (HF) in the Changning Shale Gas Field located in the Sichuan Basin, China. The analysis includes water-quality parameters, corrosion electrochemical properties, as well as bacterial and archaeal community structure. The results show that changes occurred at different exploration stages to the main corrosion microorganisms in the FP water, including bacteria and archaea, and their corrosion mechanisms. In the flowback stage, the genera Pseudomonas , Caenispirillum , Proteiniphilum , and Methanothermobacter were the main corrosive microbiota, whereas sulfur-cycling bacteria such as Arcobacter , Marinobacterium , and Desulfuromonas played the main corrosive role during the production period. After two months of production, the genus Arcobacter was highly enriched in the produced water, which is an atypical sulfate-reducing bacteria genus, and the corrosion rate reached 0.2518 mm/a as determined by corrosion electrochemistry. This study characterized the corrosivity of FP water intuitively using electrochemical tests and broadened the horizons of the corrosion mechanism caused by microbial succession over the shale gas exploitation and production stages. It may provide novel guidance for the treatment of FP water for recycling and corrosion protection in shale gas production. • The corrosivity of flowback and produced water was characterized by corrosion electrochemistry. • The genus Arcobacter was highly enriched in the produced water after two months of shale gas well production. • Sulfur-cycling bacteria was the main corrosive microorganism in the produced water. [ABSTRACT FROM AUTHOR]

For XC gas field producing large quantities of formation water that is high salinity and difficult to treat, three dirty water treatment methods were used including the reaching standard discharge, reinjection of formation water and low temperature multi-effect distillation. Field tests have shown that the reaching standard discharge is limited for further development in the gas fields due to the high investment and processing costs; the reinjection of formation water and low temperature distillation method gradually become the focus in XC gas field water treatment mode because of its low investment, high treatment efficiency, and resource recycling. [ABSTRACT FROM AUTHOR]

• A framework to determine sensitive monitoring and diagnostic indicators. • Authentic formation water originated from seawater and mixed with meteoric water. • Cl, Br, Na, Li, Ba, 87Sr/87Sr, and δ11B are the most sensitive indicators. • About 0.05% of formation water in shallow groundwater can be identified. • A groundwater contamination case has confirmed the effectiveness of the method. Potential environmental impacts on shallow groundwater from shale gas development facilitated by horizontal drilling and hydraulic fracturing is a widely debated "hot topic". In terms of potential aqueous phase contamination (including flowback fluids and produced water), there is a large gap in knowledge of the indicators for routine monitoring and contamination tracing, which should be considered critical and should be prioritized for analysis. Since formation water from shale formations is the main source of flowback fluids and produced water, and there are significant differences in some specific inorganic geochemical and isotopic compositions between shallow groundwater and formation water, this study has provided a framework to determine sensitive monitoring and diagnostic indicators for tracing potential groundwater contamination from produced water using end-member analysis. The results from a case study of the Fuling Gasfield, Sichuan Basin, SW China as the first and largest commercial shale gas development site in China, shows that produced authentic formation water with similar Br/Cl and Na/Cl ratio with seawater and low δ2H and δ18O values compared to the evaporated seawater might originate from evaporated seawater modified by water-rock interactions and be mixed with fresh meteoric water. The inorganic geochemical and isotopic indicators, such as Ba, Li, Na, Cl, Br, 87Sr/86Sr (as ε Sr sw) and δ11B are sensitive to the detection of contamination of fresh shallow groundwater by produced formation water, even in very small fractions (0.05%). Meanwhile, we present a groundwater contamination case related to shale gas development in the Fuling Gasfield. The robust conservative geochemical (Cl and Br) and isotopic (δ11B and ε Sr sw) mass balances show that 0.2–0.9% of formation water entered the shallow groundwater causing contamination. The case has also confirmed the effectiveness of those indicators. Findings from this study may help to improve groundwater monitoring and environmental regulations in countries with shale gas exploration and development. [ABSTRACT FROM AUTHOR]