GEOCHEMICAL MODEL FOR THE FORMATION OF THE MEDEK PLATINUM-BEARING DUNITE-WEHRLITE MASSIF (East Sayan, Russia)

2018 ◽  
Vol 59 (12) ◽  
pp. 2011-2026
Author(s):  
A.S. Mekhonoshin ◽  
T.B. Kolotilina ◽  
A.A. Doroshkov
Keyword(s):  
Geochemical Model

Application of geochemical model for monitoring the superviscous oil deposits development by the thermal steam methods

2017 ◽  
pp. 104-107 ◽  
Author(s):  
A.E. Chemodanov ◽  
◽  
V.A. Sudakov ◽  
S.A. Usmanov ◽  
R.K Khairtdinov ◽  
...  
Keyword(s):  
Geochemical Model ◽  
Oil Deposits

The geochemical model of Mars: An estimation from the high pressure experiments

1992 ◽  
Vol 19 (22) ◽  
pp. 2239-2242 ◽  
Author(s):  
Eiji Ohtani ◽  
Noriko Kamaya
Keyword(s):  
High Pressure ◽  
Geochemical Model

Genesis and evolution of the fumaroles of vulcano (Aeolian Islands, Italy): a geochemical model

1981 ◽  
Vol 44 (3) ◽  
pp. 547-563 ◽  
Author(s):  
M. Carapezza ◽  
P. M. Nuccio ◽  
M. Valenza
Keyword(s):  
Aeolian Islands ◽  
Geochemical Model

Geochemical Modeling on Effect of Active Species, Ca2+, Mg2+ and SO2-4 on the Carbonate Rock Surface, in Connection to Wettability Alteration of the Rock

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Vladimir Alvarado
Keyword(s):  
Contact Angle ◽  
Surface Charge ◽  
Oil Recovery ◽  
Carbonate Rock ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Rock Properties ◽  
Carboxyl Group ◽  
Geochemical Model ◽  
Positively Charged

Abstract A large percentage of petroleum reserves are located in carbonate reservoirs, which can be divided into limestone, chalk and dolomite. Roughly the oil recovery from carbonates is below the 30% due to the strong oil wetness, low permeability, abundance of natural fractures, and inhomogeneous rock properties Austad (2013). Injection of adjusted brine chemistry into carbonate reservoirs has been reported to increase oil recovery by 5-30% of the original oil in place in field tests and core flooding experiments. Previous studies have shown that adjusted waterflooding recovery in carbonate reservoirs is dependent on the composition and ionic strength of the injection brine (Morrow et al. 1998; Zhang 2005). Many research works have focused on the role of the brine composition in altering the initial wettability state of carbonate rock, which is usually intermediate- to oil-wet. Crude oils contain carboxyl group, -COOH, that can be found in the resin and asphaltenes fractions. The negatively charged carboxyl group, -COOH bond very strongly with the positively charged, sites on the carbonate surface. The carbonate surface, which is positively charged is believed to adsorb the SO42− that is negatively charged. On the other side cations Ca2+ and Mg2+ bind to the negatively charged carboxylic group and release it from the surface. In this study we use a closed system geochemical model to study the effect of the surface-charge dominant species; Ca2+, Mg2+ and SO42− on the carbonate surfaces at 80 °C. The proposed geochemical interactions can possibly lead to a change in the surface charge, altering wettability of the rock by exchanging ions/cations. Brines with various concentrations of Mg2+ and SO42− were prepared in the lab and contact angle between carbonate substrate and crude oil was measured using a rising/captive bubble tensiometer at 80 °C. The composition of the carbonate system was collected from previous literature review and the composition of adjusted brines was used to build a surface sorption database to develop a geochemical model. This model is focused on identifying the reaction paths and the surface behavior that may represent the real system. Changes in carbonate surface wettability were further evaluated using a series of contact angle experiments. Experimental observations and modeling results are concordant and imply that SO42− ions may alter the wettability of carbonate surface at high temperature.

scholarly journals Hydrochemical Changes and Influencing Factors in the Dongkemadi Region, Tanggula Range, China

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1856
Author(s):  
Tianding Han ◽  
Yuping Li ◽  
Jia Qin ◽  
Xiangying Li ◽  
Qin Yang ◽  
...  
Keyword(s):  
River Water ◽  
Chemical Weathering ◽  
River Flow ◽  
Major Ions ◽  
Meteorological Data ◽  
Atmospheric Precipitation ◽  
Dilution Effect ◽  
Ion Concentration ◽  
Rock Interaction ◽  
Geochemical Model

In order to detect the source and controlling factors of hydrochemical ions in glacier meltwater-recharged rivers, the chemical characteristics of the river water, precipitation, and meltwater of the Dongkemadi River Basin, China, in 2014 (from May to October) were systematically analyzed, and combined with the hydrological and meteorological data. The results show that the hydrochemical pattern of the typical river was HCO3−-Ca2+. The most cations were Ca2+ and Mg2+, and the predominant anions were HCO3− and SO42−, in the river. The concentration of major ions and total dissolved solids (TDS) in the river water were much larger than that in the precipitation and meltwater. The TDS concentration was ordered: River water > precipitation > meltwater. The water-rock interaction and the dilution effect of the precipitation and meltwater on the runoff ions resulted in a negative correlation between the ion concentration of the river water and the river flow. The chemical ions of the river runoff mainly originated from rock weathering and the erosion (abrasion) caused by glacier movement. In addition, the contributions of different sources to the dissolved components of the Dongkemadi River were ordered: Carbonate (75.8%) > silicate (15.5%) > hydatogenic rock (5.7%) > atmospheric precipitation (3%), calculated by a forward geochemical model. And the hydrochemical weathering rates of carbonate and silicate minerals were 12.30 t·km−2·a−1 and 1.98 t·km−2·a−1, respectively. The CO2 fluxes, consumed by the chemical weathering of carbonate and silicate, were 3.28 × 105 mol·km−2·a−1 and 0.91 × 105 mol·km−2·a−1, respectively.

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