The Chemistry of Secondary Porosity

Surdam, Ronald C.; Boese, Steven W.; Crossey, Laura J.

doi:10.1306/m37435c8

“…Meanwhile thermochemical sulfate reduction has certain influence on carbonate reservoirs (Hanor, 1993;Worden and Smalley, 1996;Heward et al, 2000;Machel, 2001;Beavington-Penney et al, 2008;Hao et al, 2015). Worden and Smalley (1996) through the analysis of the water salinity of the carbonate reservoirs of the Khuff Formation in Abu Dhabi, the thermochemical sulfate reduction produces a large amount of fresh water, and the mixing with the strata water, resulting in a decrease in the salinity of the strata water (Surdam et al, 1984;Gluyas The division points of the crude oil cracking stage are: EasyRo ≤ 1.5%, 1.5% < EasyRo < 2.5%, and EasyRo ≥ 2.5%. and Coleman, 1992).…”

Section: Thermochemical Sulfate Reduction (Tsr)mentioning

confidence: 99%

Enrichment Mechanism and Prospects of Deep Oil and Gas

Hao

¹

2022

Acta Geologica Sinica (Eng)

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With the deepening of oil and gas exploration, the importance of depth is increasingly highlighted. The risk of preservation of storage space in deep reservoirs is greater than that in shallow and medium layers. Deep layers mean older strata, more complex structural evolution and more complex hydrocarbon accumulation processes, and even adjustment and transformation of oil and gas reservoirs. This paper systematically investigates the current status and research progress of deep oil and gas exploration around the world and looks forward to the future research focus of deep oil and gas. In the deep, especially the ultra-deep layers, carbonate reservoirs play a more important role than clastic rocks. Karst, fault•karst and dolomite reservoirs are the main types of deep and ultra-deep reservoirs. The common feature of most deep large and medium-sized oil and gas reservoirs is that they formed in the early with shallow depth. Fault activity and evolution of trap highs are the main ways to cause physical adjustment of oil and gas reservoirs. Crude oil cracking and thermochemical sulfate reduction (TSR) are the main chemical modification effects in the reservoir. Large-scale high-quality dolomite reservoirs is the main direction of deep oil and gas exploration. Accurate identification of oil and gas charging, adjustment and reformation processes is the key to understanding deep oil and gas distribution. High-precision detection technology and high-precision dating technology are an important guarantee for deep oil and gas research.

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“…The abundance of other monocarboxylic acid anions generally decreases with increasing number of carbon atoms (acetate > propionate > butyrate > valerate) (Carothers and Kharaka 1978; Fisher and Boles 1990;Kharaka et al 1987). Formate ( CHOO − ) does not seem to follow this trend with a reported maximum concentration of 174 mg L −1 in oil-field waters (Kharaka et al 1985a;MacGowan and Surdam 1988;Surdam et al 1984). Concentrations of dicarboxylic acid anions range from 0 to 2540 mg L −1 in formation waters from sedimentary basins (Kharaka et al 2000;MacGowan and Surdam 1988).…”

Section: Types Origin and Occurrence Of Organic Compounds In Deep Sub...mentioning

confidence: 99%

“…Implementing organic compound analyses in addition to the inorganic components, might greatly improve the understanding of the fluid-chemical properties. Specifically, carboxylic acids are known to act as strong complexing ligands for metals (Kharaka and Hanor 2003;Seewald 2001;Surdam et al 1984). Organic geochemistry could be used as complementary tool to understand fluid dynamics and circulation within a reservoir as it was done and discussed for the Los Humeros geothermal field, Mexico, in Sánchez-Avila et al (2021).…”

mentioning

confidence: 99%

Dissolved organic compounds in geothermal fluids used for energy production: a review

Leins

¹

,

Bregnard²,

et al. 2022

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Dissolved organic matter (DOM) can be found in a variety of deep subsurface environments such as sedimentary basins, oil fields and mines. However, the origin, composition and fate of DOM within deep geothermal reservoirs used for energy production is relatively unknown. With well depths reaching a few kilometers, these sites give access to investigate deep subsurface environments. Natural DOM as well as artificial DOM (e.g., from chemical scaling inhibitors) might serve as nutrients for microorganisms or affect chemical properties of the fluids by complexation. Its composition might reveal hydraulic connections to organic-rich strata, giving insights to the fluid flow within the reservoir. This review presents an overview of a total of 143 fluid samples from 22 geothermal sites (mainly central Europe), from the literature and compiling data to address the importance of DOM in geothermal fluids and how it might affect geothermal operation. The environmental conditions of the sites included varied greatly. Temperatures range from 34 to $$200\,^{\circ }\hbox {C}$$ 200 ∘ C , depths from 850 to 5000 m, chloride content from 0.1 to $$160\,{\hbox {g}\,\hbox {L}^{-1}}$$ 160 g L - 1 , and dissolved organic carbon (DOC) concentrations from 0.1 to $$30.1\,{\hbox {g}\,\hbox {L}^{-1}}$$ 30.1 g L - 1 . The DOC concentrations were found to be generally lower in the fluids with temperatures below $$80\,{}^{\circ }\hbox {C}$$ 80 ∘ C . DOC concentrations were higher in fluids with temperatures above $$80\,{}^{\circ }\hbox {C}$$ 80 ∘ C and showed a decrease towards $$200\,{}^{\circ }\hbox {C}$$ 200 ∘ C . Microbial degradation might be the main driver for low DOC concentrations in the lower temperature range (below $$80\,{}^{\circ }\hbox {C}$$ 80 ∘ C ), while thermal degradation likely accounts for the decline in DOC in the temperature region between $$80\,{}^{\circ }\hbox {C}$$ 80 ∘ C and $$200\,{}^{\circ }\hbox {C}$$ 200 ∘ C . This review shows that DOM can be found in a variety of geothermal reservoirs and that it could be an additional essential tool to better understand fluid chemistry and reservoir conditions, and to optimize geothermal operation.

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“…The O-atoms of the malonate ion are positioned to chelate a metal ion to form a six-member ring. Such complexation of Al 3+ is thought to contribute to the secondary porosity of sandstone, 13 although this source of secondary porosity has been disputed. 14 Nonetheless, association of malonate with metal ions is potentially important in Earth processes.…”

Section: Introductionmentioning

confidence: 99%

“…The O-atoms of the malonate ion are positioned to chelate a metal ion to form a six-member ring. Such complexation of Al 3+ is thought to contribute to the secondary porosity of sandstone, although this source of secondary porosity has been disputed . Nonetheless, association of malonate with metal ions is potentially important in Earth processes. − To understand the role of the cation in determining the decarboxylation rate of malonate(−1), we studied solutions in which Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , and Sr 2+ were the counterions.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy of Hydrothermal Reactions 15. The pH and Counterion Effects on the Decarboxylation Kinetics of the Malonate System

Gunawardena

¹

,

Brill

²

2001

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Malonic acid (HO2CCH2CO2H) and its anions malonate(−1) (HO2CCH2CO2 -) and malonate(−2) (-O2CCH2CO2 -) are among the more abundant dicarboxylates in natural water. Two variables influencing their behavior are the pH and the counterion. The rate constants for decarboxylation were determined in the pH range of 1.89−7.0 with a flow reactor−FTIR spectroscopy cell operating at 140−240 °C and 275 bar. The relative rates of the first-order reactions are malonic acid > malonate(−1) ≫ malonate(−2). The Arrhenius activation energies are similar for the three species (116−120 kJ/mol), making the rate differences controlled primarily by the pre-exponential factors ln(A, s-1) = 30.2, 28.3, and 23.3, respectively]. These findings are interpreted in terms of the role of entropy in a cyclic intermediate common to all three species. Malonate(−2) is proposed to form this structure by hydration to 1-orthomalonate(−2). The entropy decreases as the negative charge increases due to increased rigidity of the cyclic intermediate and increased electrostriction of the solvation shell. The influence of the Group 1 and 2 cations Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, and Sr2+ on the decarboxylation rate of malonate(−1) was determined. Except for Mg2+, the rate decreases with increasing ionic potential (ion charge/ion radius), which is consistent with increasing replacement of H by the metal ion in the six-member cyclic intermediate. Mg2+ is anomalous possibly because it forms the strongest complex with malonate(−1) and decarboxylates by a different mechanism.

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The Chemistry of Secondary Porosity

Cited by 121 publications

References 2 publications

Enrichment Mechanism and Prospects of Deep Oil and Gas

Enrichment Mechanism and Prospects of Deep Oil and Gas

Dissolved organic compounds in geothermal fluids used for energy production: a review

Spectroscopy of Hydrothermal Reactions 15. The pH and Counterion Effects on the Decarboxylation Kinetics of the Malonate System

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