Geochemical processes during hydraulic fracturing: a water-rock interaction experiment and field test study

2017 ◽  
Vol 21 (5) ◽  
pp. 753-763 ◽  
Author(s):  
Yiman Li ◽  
Tianming Huang ◽  
Zhonghe Pang ◽  
Chao Jin
Author(s):  
Cole Messa

The hot springs of Yellowstone National Park provide a broad range of isotopic data (e.g. 238U-, 235U-, and 232Th-series) that can be exploited to interpret the geochemical processes occurring at depth, including water-rock interaction, nuclide sourcing, and fluid residence times. Despite its worldwide notoriety, Yellowstone’s hydrothermal system remains largely unconstrained. While major advances in the past century have helped us to understand the highly varied geochemical characteristics of Yellowstone’s thermal features and their potential mechanisms of formation, many questions remain regarding where exactly the water resides before ascending to the surface, how long the water remains at depth, and what geochemical processes are occurring between these waters and the superheated aquifer rocks. One of the primary questions surrounding the Yellowstone hydrothermal system revolves around the concept of “phase separation”, whereby ascending, pressurized hydrothermal fluids undergo decompressional boiling and separate into an acidic vapor phase and a neutral fluid phase. These diverging phases result in the two dominant spring chemistries viewed on the surface, acid-sulfate springs and neutral-chloride springs. Still, little is known about the timescales such a process operates on, and what geochemical parameters can be constrained to support the existence of this model. Herein we examine a handful of hydrothermal features throughout Yellowstone National Park in an effort to investigate the likelihood of phase separation’s existence and whether or not the isotopic evidence supports the geochemical processes that we know to be occurring should this model persist within the plumbing of a continental hydrothermal system.   Featured photo from figure 3 in report. 


SPE Journal ◽  
2020 ◽  
Vol 25 (02) ◽  
pp. 788-799 ◽  
Author(s):  
Lifu Zhang ◽  
Michael Tice ◽  
Berna Hascakir

Summary Reuse of flowback water in hydraulic fracturing is usually used by industry to reduce consumption, transportation, and disposal cost of water. However, because of complex interactions between injected water and reservoir rocks, induced fractures may be blocked by impurities carried by flowback and mineral precipitation by water/rock interactions, which causes formation damage. Therefore, knowledge of flowback water/rock interactions is important to understand the changes within the formation and effects on hydraulic fracturing performance. This study focuses on investigating flowback water/rock interactions during hydraulic fracturing in Marcellus Shale. Simple deionized water (DI)/rock interactions and complicated flowback water/rock interactions were studied under static and dynamic conditions. In static experiments, crushed reservoir rock samples were exposed to water for 3 weeks at room condition. In the dynamic experiment, continuous water flow interacted with rock samples through the coreflooding experimental system for 3 hours at reservoir condition. Before and after experiments, rock samples were characterized to determine the change on the rock surfaces. Water samples were analyzed to estimate the particle precipitation tendency and potential to modify flow pathway. Surface elemental concentrations, mineralogy, and scanning electron microscope (SEM) images of rock samples were characterized. Ion contents, particle size, total dissolved solids (TDS), and zeta-potential in the water samples were analyzed. After flowback water/rock interaction, the surface of the rock sample shows changes in the compositions and more particle attachment. In produced water, Na, Sr, and Cl concentrations are extremely high because of flowback water contamination. Water parameters show that produced water has the highest precipitation tendency relative to all water samples. Therefore, if flowback water without any treatment is reused in hydraulic fracturing, formation damage is more likely to occur from blockage of pores. Flowback water management is becoming very important due to volumes produced in every hydraulic fracturing operation. Deep well injection is no longer a favorable option because it results in disposal of high volumes of water that cannot be used for other purposes. A second option is the reuse of waste water for fracturing purposes, which reduces freshwater use significantly. However, the impurities present in flowback water may deteriorate the fracturing job and reduce or block the hydraulic fracturing apertures. This study shows that a simple filtration process applied to the flowback water allows for reinjection of the flowback water without further complication to the water/rock interaction, and does not cause significant formation damage in the fractures.


Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaocui Wang ◽  
Xun Zhou

Travertine and nontravertine thermal springs have been studied in Yunlong County in southwest China to determine the geothermal reservoir temperatures and to find the geochemical processes that affect the evolution of thermal groundwater constituents during subsurface circulation. Hydrochemical characteristics distinguish travertine from nontravertine types. Travertine springs show HCO3·Cl-Na and SO4·HCO3-Ca·Na type, and a nontravertine spring presents Cl·HCO3·SO4-Na type. Log(Q/K) versus T diagrams show that reservoir temperatures can be expressed as intervals based on the equilibrium mineral assemblages coexisting in equilibrium and multiminerals in equilibrium with the aid of the PHREEQC and WATCH programs. The spring water mixing ratio with shallow water is between 59% and 82% with steam loss ranging from 12.1% to 27.8%. The Dalang Spring mixes with the highest proportion of cold water (76% to 82%) among the four hot springs and has the highest geothermal reservoir temperature (132°C to 176.9°C). The water-rock interaction during recharge from precipitation demonstrates that the minerals halite, kaolinite, chalcedony, plagioclase, and CO2(g) play an important part in the evolution of the thermal groundwater. Four inverse modeling simulation paths between precipitation and spring discharge were established to calculate the mass flux of minerals by the PHREEQC program. Halite, kaolinite, chalcedony, plagioclase, and CO2(g) participate in dissolution reactions in the thermal groundwater circulation, while gypsum, calcite, dolomite, biotite, and fluorite keep the geochemical processes in equilibrium.


1998 ◽  
Author(s):  
Fred Levien ◽  
Paul Buczynski
Keyword(s):  

2020 ◽  
Author(s):  
Marie Haut-Labourdette ◽  
◽  
Daniele Pinti ◽  
André Poirier ◽  
Marion Saby ◽  
...  

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Otman EL Mountassir ◽  
Mohammed Bahir ◽  
Driss Ouazar ◽  
Abdelghani Chehbouni ◽  
Paula M. Carreira

AbstractThe city of Essaouira is located along the north-west coast of Morocco, where groundwater is the main source of drinking, domestic and agricultural water. In recent decades, the salinity of groundwater has increased, which is why geochemical techniques and environmental isotopes have been used to determine the main sources of groundwater recharge and salinization. The hydrochemical study shows that for the years 1995, 2007, 2016 and 2019, the chemical composition of groundwater in the study area consists of HCO3–Ca–Mg, Cl–Ca–Mg, SO4–Ca and Cl–Na chemical facies. The results show that from 1995 to 2019, electrical conductivity increased and that could be explained by a decrease in annual rainfall in relation to climate change and water–rock interaction processes. Geochemical and environmental isotope data show that the main geochemical mechanisms controlling the hydrochemical evolution of groundwater in the Cenomanian–Turonian aquifer are the water–rock interaction and the cation exchange process. The diagram of δ2H = 8 * δ18O + 10 shows that the isotopic contents are close or above to the Global Meteoric Water Line, which suggests that the aquifer is recharged by precipitation of Atlantic origin. In conclusion, groundwater withdrawal should be well controlled to prevent groundwater salinization and further intrusion of seawater due to the lack of annual groundwater recharge in the Essaouira region.


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