scholarly journals Geochemical Characteristics and Productivity Response of Produced Water from Coalbed Methane Wells in the Yuwang Block, Eastern Yunnan, China

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mingyang Du ◽  
Xiaojuan Yao ◽  
Shasha Zhang ◽  
He Zhou ◽  
Caifang Wu ◽  
...  
Keyword(s):  
Water Samples ◽  
Coalbed Methane ◽  
Produced Water ◽  
Dissolved Inorganic Carbon ◽  
Geochemical Characteristics ◽  
Water Type ◽  
Coal Seams ◽  
Rock Interaction ◽  
Cbm Production ◽  
Using Data

Coalbed methane (CBM) well-produced water contains abundant geochemical information that can guide productivity predictions of CBM wells. The geochemical characteristics and productivity responses of water produced from six CBM wells in the Yuwang block, eastern Yunnan, were analyzed using data of conventional ions, hydrogen and oxygen isotopes, and dissolved inorganic carbon (DIC). The results showed that the produced water type of well L-3 is mainly Na-HCO3, while those from the other five wells are Na-Cl-HCO3. The isotope characteristics of produced water are affected greatly by water-rock interaction. Combined with the enrichment mechanisms of isotopes D and 18O, we found that the water samples exhibit an obvious D drift trend relative to the local meteoric water line. The 13C enrichment of DIC in the water samples suggests that DIC is mainly produced by the dissolution of carbonate minerals in coal seams. The concentration of HCO3-, D drift trend, and enrichment of 13CDIC in produced water are positively correlated with CBM production, which can be verified by wells L-4 and L-6.

scholarly journals Geochemical characteristics of produced water from coalbed methane wells and its influence on productivity in Laochang Coalfield, China

2020 ◽  
Vol 12 (1) ◽  
pp. 1146-1157
Author(s):  
Mingyang Du ◽  
Caifang Wu ◽  
He Zhou ◽  
Shasha Zhang ◽  
Erchao Zhang
Keyword(s):  
Coalbed Methane ◽  
Produced Water ◽  
Geochemical Characteristics ◽  
Water Production ◽  
Coal Seams ◽  
Quantitative Characterization ◽  
Rock Interaction ◽  
Well Production ◽  
Water Rock Interaction ◽  
Production Characteristics

AbstractThe water produced from the coalbed methane (CBM) wells contains abundant geochemical information, which is of great significance in evaluating the productivity of these wells. Based on the data of water produced from five CBM wells, geochemical characteristics of the produced water and its influence on the productivity of the wells are analyzed in Laochang Block. The results show that with the increase in the produced water of the five wells, δD and δ18O show a downward trend in general, reflecting that the influence of coal seams and surrounding rock on the produced water is weak, while the water–rock interaction of the Y-3 and Y-5 wells is more stable than that of the Y-1, Y-2, and Y-4 wells. Combining the water production characteristics of the Y-3 and Y-5 wells with better drainage and recovery effects, it is proposed that 0 ≤ σM < 0.3 and 0 ≤ σY < 600 or 0.7 < σM < 0.8 and 1,200 < σY < 1,300, and the fluctuation ranges of Ca2+, Mg2+, HCO3− and SO42− can provide a basis for quantitative characterization and evaluation of CBM well production.

scholarly journals Biogeochemistry and the associated redox signature of co-produced water from coalbed methane wells in the Shizhuangnan block in the southern Qinshui Basin, China

2020 ◽  
Vol 38 (4) ◽  
pp. 1034-1053
Author(s):  
Yang Li ◽  
Shuheng Tang ◽  
Songhang Zhang ◽  
Zhaodong Xi ◽  
Pengfei Wang
Keyword(s):  
Coalbed Methane ◽  
Produced Water ◽  
Dissolved Inorganic Carbon ◽  
Gas Production ◽  
Redox Conditions ◽  
Effective Parameters ◽  
Production Rates ◽  
Qinshui Basin ◽  
Southern Qinshui Basin ◽  
Biogeochemical Parameters

To meet the global energy demands, the exploitation of coalbed methane has received increasing attention. Biogeochemical parameters of co-produced water from coalbed methane wells were performed in the No. 3 coal seam in the Shizhuangnan block of the southern Qinshui Basin (China). These biogeochemical parameters were firstly utilized to assess coal reservoir environments and corresponding coalbed methane production. A high level of Na+ and HCO3– and deuterium drift were found to be accompanied by high gas production rates, but these parameters are unreliable to some extent. Dissolved inorganic carbon (DIC) isotopes δ13CDIC from water can be used to distinguish the environmental redox conditions. Positive δ13CDIC values within a reasonable range suggest reductive conditions suitable for methanogen metabolism and were accompanied by high gas production rates. SO42–, NO3– and related isotopes affected by various bacteria corresponding to various redox conditions are considered effective parameters to identify redox states and gas production rates. Importantly, the combination of δ13CDIC and SO42– can be used to evaluate gas production rates and predict potentially beneficial areas. The wells with moderate δ13CDIC and negligible SO42– represent appropriate reductive conditions, as observed in most high and intermediate production wells. Furthermore, the wells with highest δ13CDIC and negligible SO42– exhibit low production rates, as the most reductive environments were too strict to extend pressure drop funnels.

scholarly journals Review of the Hydrogeological Controls on Coalbed Methane (CBM) and Development Trends

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Bo Wang ◽  
Dangliang Wang ◽  
Wenjie Cao ◽  
Guofu Li ◽  
Wei Hou ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Coalbed Methane ◽  
Produced Water ◽  
Isotope Analysis ◽  
Atmospheric Precipitation ◽  
Low Rank ◽  
Theoretical Research ◽  
Water Type ◽  
Development Trends ◽  
Fracture Development

Hydrogeological conditions can control the generation, preservation, enrichment, and production of coalbed methane (CBM) in the field; however, research on these impacts is insufficient, resulting in the limitation of the development of coalbed methane. This paper summarizes the current research status and development trends of the effect of hydrogeology on CBM using methods such as mathematical statistics, literature analysis, well logging, and hydrochemical analysis. The results indicate that it is beneficial for the generation of secondary biogenic gases in low-rank coal seams under the situations like active hydrodynamic conditions with a salinity less than 1000 mg/L, a pH range from 5.9 to 8.8, or a range of oxidation-reduction potential from -540 mV to -590 mV. The abnormally high temperature due to the magmatic-hydrothermal fluids accelerates the metamorphism of coal rocks, leading to the promotion of the generation of thermogenic gases. When the coalbed structural conditions of one area are similar to the depositional conditions in that area, the CBM is accumulated if the conditions of that area meet the following criteria: the water type is NaHCO3, the salinity is greater than 1500 mg/L, the desulfurization coefficient is less than 1, and the sodium-chloride coefficient is less than 10. The stable isotope analysis of CBM well-produced water shows that the δD values in the groundwater shift to the left of the global meteoric water line, indicating that the produced water comes from atmospheric precipitation. In the CBM enrichment zone, the area with a relatively high salinity and a low sodium-chloride coefficient is the high-production area. Based on our study, three high CBM-production patterns are summarized: coalbed structure-hydraulic trapping, fold limb-fracture development, and syncline core-water stagnation. Additionally, four development trends of the control of hydrogeology on CBM are proposed: transformation from qualitative evaluation to quantitative evaluation, from a singular evaluation standard to multiple evaluation standards, from static evaluation to dynamic evaluation, and from pure theoretical research to theoretical guidance on production practices.

Evaluation of the Geochemical Characteristics and Exploitation Potential of Produced Water from Coalbed Methane Wells in Eastern Yunnan, China

2021 ◽  
Vol 21 (1) ◽  
pp. 591-598
Author(s):  
Mingyang Du ◽  
Caifang Wu ◽  
Shasha Zhang ◽  
Xiaolei Liu
Keyword(s):  
Coal Seam ◽  
Trace Element ◽  
Coalbed Methane ◽  
Element Concentration ◽  
Produced Water ◽  
Trace Element Concentration ◽  
Surrounding Rock ◽  
Geochemical Characteristics ◽  
Drainage Time

Based on the analysis of the geochemical characteristics of the produced water from coalbed methane wells in eastern Yunnan, the effects of the water-rock interactions on the produced water were discussed, and the mining potential of each of the four wells was evaluated. The results show that with the increase in drainage time, the Na+ and Cl− concentrations decrease while the HCO−3 concentration increases. The produced water from the two wells in the Enhong Block shows D drift characteristics, while that of the two wells in the Laochang Block shows O drift characteristics. The order of the produced water affected by the surrounding rock is D-1 well > M-1 well > D-2 well > M-2 well, and the order of the produced water influenced by the coal seam is D-1 well > D-2 well > M-1 well > M-2 well. According to the variation in the As trace element concentration, it is inferred that in the four coalbed methane wells, the D-1 and D-2 wells have a greater exploitation potential than that of the M-1 and M-2 wells. On this basis, the influencing characterization parameters of the water-rock interactions on the produced water are established.

scholarly journals Biogeochemistry and Water–Rock Interactions of Coalbed Methane Co-Produced Water in the Shizhuangnan Block of the Southern Qinshui Basin, China

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 130
Author(s):  
Yang Li ◽  
Shuheng Tang ◽  
Songhang Zhang ◽  
Zhaodong Xi ◽  
Pengfei Wang
Keyword(s):  
16S Rrna ◽  
Water Samples ◽  
Coalbed Methane ◽  
Produced Water ◽  
Major Ions ◽  
16S Rrna Sequencing ◽  
Qinshui Basin ◽  
Isotopic Compositions ◽  
Rrna Sequencing ◽  
Southern Qinshui Basin

Coalbed methane is a major unconventional resource that has been exploited commercially for decades in the southern Qinshui Basin of China. The hydrogeochemical characteristics of coal reservoir water play a key role in the exploration and development of coalbed methane resources. In view of this, a detailed study was performed on coalbed methane co-produced water collected from the Shizhuangnan block to assess water–rock interactions and biogeochemical processes. Water samples were analyzed to establish major ions, isotopic compositions and perform 16S rRNA sequencing. Results suggest that the hydrochemistry was controlled by water–rock processes and that methane was consumed by sulfate reduction through calculation. Meanwhile, the isotopic compositions of water samples indicated that they had a predominantly meteoric origin and were influenced by microbial activity. The 16S rRNA sequencing results of bacteria and archaea provide an important foundation for understanding the activity of sulfate-reducing bacteria and methanogens at different hydraulic heads, which was consistent with isotopic analysis. Carbonates containing calcite and dolomite were found to be distributed at different hydraulic head due to the biogeochemical characteristics and associated water–rock interactions.

A Laboratory Study of the Impact of Reinjecting Flowback Fluids on Formation Damage in the Marcellus Shale

SPE Journal ◽  
2020 ◽  
Vol 25 (02) ◽  
pp. 788-799 ◽  
Author(s):  
Lifu Zhang ◽  
Michael Tice ◽  
Berna Hascakir
Keyword(s):  
Hydraulic Fracturing ◽  
Water Samples ◽  
Produced Water ◽  
Marcellus Shale ◽  
Reservoir Rock ◽  
Formation Damage ◽  
Rock Interaction ◽  
Flowback Water ◽  
Rock Samples ◽  
Water Rock Interaction

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.

Fluid geochemistry in the Latronico thermal area (south Italy): new preliminary data for upcoming monitoring of a seismically active area

2020 ◽  
Author(s):  
Michele Paternoster ◽  
Carmine Apollaro ◽  
Antonio Caracausi ◽  
Paolo Randazzo ◽  
Alessandro Aiuppa ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Regional Scale ◽  
Isotopic Signature ◽  
Thermal Waters ◽  
Water Type ◽  
Dissolved Gases ◽  
Fluid Circulation ◽  
Geochemical Monitoring ◽  
Rock Interaction ◽  
Calcium Bicarbonate

&lt;p&gt;The Latronico thermal area is located in the southern sector of the Apennines chains, in proximity to the south boundary of the Mt. Alpi. This area is a seismically active region and it is located between Val d&amp;#8217;Agri basin and Pollino area, two of the highest seismic risk zones in Italy. It is well documented that tectonic discontinuities act as preferential channels for the uprise of deep fluids trough the continental crust towards the surface (e.g., Caracausi et al. 2013). Hence in seismically areas, these fluids can move across the volume of rocks characterized by an active field of stress and their fluids can take a memory of the occurring rock-water-gas interactions. Taking this into account, we sampled waters and dissolved gases released in the Latronico hydrothermal basin in order to define: i) water-rock interaction processes; ii) thermalism origin; iii) the geochemical model of fluid circulation in a seismic area. &amp;#160;In details, we analysed the chemical and isotopic (C and noble gases) composition both groundwater and dissolved gases. The acquired knowledge will allow us to plan long-term geochemical monitoring useful for identification of the possible relationship between fluid circulation and regional-scale seismicity. We sampled 24 springs, of which 9 belonging to thermal set (Latronico Spa springs) and 15 to cold one. Thermal waters have an average temperature of 21&amp;#176;C, these are slightly alkaline (7.12 &lt;pH&lt; 7.54), show negative Eh values up to &amp;#8722;93 mV and are calcium bicarbonate-sulphate water type. The cold springs have temperature values from 7.7 to 14.8 &amp;#176;C, pH from 7.05 to 8.15, with positive Eh values up to 200 mV. These waters are calcium-bicarbonate water type. The oxygen and hydrogen isotopes clearly indicate their meteoric origin. Regarding the gas geochemistry, He and C isotopes have been used as the key tracer for recognizing the contribution of crustal and mantle components and possibly the source of heat. Thermal waters have CO&lt;sub&gt;2 &lt;/sub&gt;and He contents of 1 and 2 order of magnitude higher than cold water, respectively. The dissolved gases show an atmospheric component, being Air Saturated Water (ASW). &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He ratios in the gases dissolved are 0.12 Ra &amp;#177;0.2 (Ra is the He isotopic signature in the atmosphere, 1.39x10&lt;sup&gt;-6&lt;/sup&gt;). Assuming that He isotopic signature in typical crustal fluids is &lt; 0.05 Ra, the measured He data show traces of mantle-derived helium, to the mixing between atmospheric and radiogenic end-members (0.02 Ra). Coupling Total Dissolved Inorganic Carbon (TDIC) and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;TDIC&lt;/sub&gt; data, 2 water sub-sets have been identified: (i) infiltrating waters, with low &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;TDIC&lt;/sub&gt;, and (ii) thermal waters with positive &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;TDIC&lt;/sub&gt; and high TDIC values, indicative of outgassing of deeply sourced CO&lt;sub&gt;2&lt;/sub&gt;. This study for the first time proposes a model of fluids origin in the Latronico hydrothermal basin and the main processes that control their chemistry during their circulation through the crust. Hence, geochemical monitoring of the fluids in the region can provide if these fluids are sensitive to chemical variation due to a modification of the field of stress in the preparatory phases of an earthquake&lt;/p&gt;

scholarly journals Water–rock interaction and the concentrations of major, trace, and rare earth elements in hydrocarbon-associated produced waters of the United States

2021 ◽  
Author(s):  
Carleton R. Bern ◽  
Justin E. Birdwell ◽  
Aaron M. Jubb
Keyword(s):  
United States ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Water Chemistry ◽  
Produced Water ◽  
The United States ◽  
Rock Interaction ◽  
Produced Waters ◽  
Water Rock Interaction

Comparisons of hydrocarbon-produced waters from multiple basins and experiments using multiple shales illustrate water–rock interaction influence on produced water chemistry.

scholarly journals Environmental Risk Related to the Exploration and Exploitation of Coalbed Methane

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6537
Author(s):  
Barbara Uliasz-Misiak ◽  
Jacek Misiak ◽  
Joanna Lewandowska-Śmierzchalska ◽  
Rafał Matuła
Keyword(s):  
Coalbed Methane ◽  
Environmental Risks ◽  
Risk Category ◽  
Burial History ◽  
Exploration And Exploitation ◽  
Coal Seams ◽  
Mining Operations ◽  
Environmental Threats ◽  
And Migration ◽  
Coal Macerals

In coal seams, depending on the composition of coal macerals, rank of coal, burial history, and migration of thermogenic and/or biogenic gas. In one ton of coal 1 to 25 m3 of methane can be accumulated. Accumulation of this gas is included in unconventional deposits. Exploitation of methane from coal seams is carried out with wells from mining excavations (during mining operations), wells drilled to abandoned coal mines, and wells from the surface to unexploited coal seams. Due to the low permeability of the coal matrix, hydraulic fracturing is also commonly used. Operations related to exploration (drilling works) and exploitation of methane from coal seams were analyzed. The preliminary analysis of the environmental threats associated with the exploration and exploitation of coalbed methane has made it possible to identify types of risks that affect the environment in various ways. The environmental risks were estimated as the product of the probability weightings of adverse events occurring and weightings of consequences. Drilling operations and coalbed methane (CBM) exploitation leads to environmental risks, for which the risk category falls within the controlled and accepted range.

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