Geochemistry of Radioactive Isotopes

The chapter targeted the geochemistry of radioactive isotopes dealing with multidisciplinary topics and focusing on geochronology and tracer studies. The most common subjects are presented to include the basic principles of radioactive isotopes. The radioactive decay, the parent nuclide, the SI unit of radioactive decay as well as the historical discovery of radioactivity, the neutrons and protons in atomic nuclei, alpha and beta particles, gamma rays, electromagnetic radiation, decay and mode of decay, chain of decay, decay rates, decay timing, principle of dating, radiometric dating, isotope systems, the Rb/Sr System, the U, Th, Pb System, the age of the earth, Sm-Nd dating, K-Ar dating, 14Carbon dating, the geochron, all those were included overall

Glass Wastes Sorption Efficiency for Removing Cadmium from Aqueous Solutions

This research aims to test the ability of glass waste powder to adsorb cadmium from aqueous solutions. The glass wastes were collected from the Glass Manufacturing Factory in Ramadi. The effect of concentration and reaction time on sorption was tested through a series of laboratory experiments. Four Cd concentrations (20, 40, 60, and 80) as each concentration was tested ten times for 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 min. Solid (glass wastes) to liquid was 2g to 30ml was fixed in each experiment where the total volume of the solution was 30ml. The pH, total dissolved salts and electrical conductivity were measured at 30ºC. The equilibrium concentration was determined at 25 minutes, thereafter it was noted that the sorption (%) decreased whenever increasing Cd concentration. Langmuir and Freundlich's equations showed that the sorption intensity is 2.402 and the adsorption capacity is 3.126, and the sorption of Cd fits with the Freundlich equation. Consequently, it was clarified how glass waste material can be utilized for reducing the high levels of Cd concentrations from aqueous solutions as a step to combat environmental pollution

Geochemical Criteria for Discriminating Shallow and Deep Environments in Oligocene-Miocene Succession, Western Iraq

The geochemical study of the Oligocene-Miocene succession Anah, Euphrates, and Fatha formations, western Iraq, was carried out to discriminate their depositional environments. Different major and trace patterns were observed between these formations. The major elements (Ca, Mg, Fe, Mn, K, and Na) and trace elements (Li, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Zr, Cs, Ba, Hf, W, Pb, Th, and U) are a function of the setting of the depositional environments. The reefal facies have lower concentrations of MgO, Li, Cr, Co, Ni, Ga, Rb, Zr, and Ba than marine and lagoonal facies but have higher concentrations of CaO, V, and Sr than it. Whereas dolomitic limestone facies are enriched V, and U while depletion in Li, Cr, Ni, Ga, Rb, Sr, Zr, Ba, and Pb Conversely, the lagoonal facies are rich in clay minerals and associated trace elements Li, V, Cr, Co, Ni, Cu, Ga, Rb, Zr, Ba, and Pb

Purification of Aqueous Solutions from Nickel Using Ceramic Waste

This study aims to test ceramic waste's capacity to remove nickel from aqueous solutions through adsorption. Ceramic wastes were collected from the Refractories Manufacturing Plant in Ramadi. Through a series of lab tests, the reaction time (5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 minutes, and Ni concentrations (20, 40, 60, and 80) were tested using ceramic wastes with a solid to liquid ratio of 2g/30ml. At a temperature of 30ºC, the pH, total dissolved solids (TDS), and electrical conductivity (EC) were all measured. The equilibrium time was set at 30 min. Thereafter, the sorption (%) somewhat increased positively with the Ni concentration. Freundlich's equation showed that the adsorption intensity is 1.1827 and the Freundlich constant is 58.15, Langmuir Equation showed the sorption capacity is 1.8779, and the sorption of Ni fit with the Langmuir and Freundlich equations. It was clarified how ceramic waste material can reduce the Ni concentrations from aqueous solutions protecting the environment

SULFUR ISOTOPES GEOCHEMISTRY OF THE BITUMINOUS FATHA EVAPORATES IN FATHA FORMATION, HIT–ABU JIR AREA, WESTERN IRAQ

Fatha Formation (Middle Miocene) in Hit area, western Iraq was targeted for this study. Pure gypsum, bituminous gypsum and native sulfur were investigated for δ34S, FTIR and SEM to define the historical scenario of the paleo-environment and the relationship between sulfur, bitumen and evaporates (gypsum and anhydrite). SEM along with FTIR clarified that the bitumen were injected into the gypsum under high stress generated from the basin hydrodynamic pressure. The pure gypsum samples are enriched in heavy sulfur isotope and characterized by narrow range of δ34S values (22.5 – 23.52 ‰) indicating a primary gypsum formed by direct precipitation from saline without bacterial activity. The lighter sulfur values (14.13 – 14.42 ‰) in the sulfur samples of the Abu-Jir area indicate a bacterial reduction of gypsum into native sulfur. The difference between δ34S values in sulfur deposits in the Abu-Jir area (14.13 – 14.42 ‰) and in the Mishraq Mine (9.51 ‰) is clearly attributed to the remnant of gypsum as impurities within sulfur deposits in the Abu-Jir area. The bitumen sample has depleted in δ34S value (-2.57 ‰), whilst the bituminous gypsum samples have enriched (22.07 – 24.11 ‰). This high variation reflects the highly isotopic fractionation between oxic and anoxic environments

Geology, Pb and S Isotope Geochemistry, and Genesis of the Na Bop-Pu Sap Lead-Zinc Deposit in the Cho Don area, Northeastern Vietnam

The Na Bop-Pu Sap Pb-Zn ore bodies represent a typical vein-type lead-zinc deposit situated in the Cho Don area and are currently being extracted for their lead and zinc resources. This deposit is characterized by its significant scale and quality and is considered one of the prominent lead-zinc deposits in the Cho Don area. Despite its significance, this deposit has not received adequate attention, resulting in limited knowledge of its geology, mineralization, and deposit genesis model. To address this knowledge gap, our study utilized several methodologies, including field surveying, ore mineral analysis under a microscope, and S and Pb isotopic geochemistry. By employing these approaches, we were able to obtain specific insights into the origin of mineralization and the deposit model. Our field survey suggests that the ore deposits are formed as Pb-Zn-bearing veins along Devonian shale, claystone, and limestone faults. Microscopic analyses of the veins reveal the presence of galena, sphalerite, chalcopyrite, pyrite, arsenopyrite, and pyrrhotite as ore minerals, and quartz, calcite, dolomite, and chalcedony as gangue minerals. Sulfur-isotope values (δ34SCDT) of galena 5.3 to 0.1‰ (average 2.8‰), sphalerite 6.8 to 2.5‰ (average 5.3‰), and pyrite 5.8 to 4.1‰ (average 4.9‰) indicate that the sulfide mineralization may be related to a deep source, possibly originating from magmatic activity in the region and contaminated by carbonate-bearing marine sedimentary rocks. Lead-isotope studies indicate a model age of 598-424 Ma for the lead reservoir, consistent with the possible presence of local source rocks containing sulfur. The lead and sulfur in the ore veins were probably contaminated by Devonian carbonate-bearing marine sedimentary rocks and leached from Neoproterozoic to Cambrian magmatic activity. The lead-zinc deposits in Na Bop-Pu Sap do not display any Mississippi valley-type (MVT) or Sedimentary exhalative (SEDEX) lead-zinc deposit characteristics, as they appear to be related to shear zone-hosted lead-zinc deposits

Fluid Inclusions Usage for Assessing Oil Migration in Duhok, North of Iraq

Studies of primary and secondary fluid inclusions were done on epigenetic barite samples which collected from carbonates in Lower part of Sarmord Formation (Lower Cretaceous and Aqra-Bekhme Formations (Upper Cretaceous) in Duhok localities of North of Iraq. Lead isotopes composition in galena which associated barite that contained fluid inclusions helped the identification two events of fluid inclusions. These fluid inclusions contain brine water and hydrocarbons. Primary and secondary fluid inclusions in barite as well as lead isotopes composition in galena helped the interpretation of oil migration history and the pathway of oil migration. Ages of galena are syngronous with the events of oil and water trapping as inclusions within barite, and hence the interpreted galena generation could be assigned to the fluid inclusions age. Accordingly, the events are two phases of early and late generations that correspond to 120 m.y. and 30 m.y. respectively. Correlation with 10 PetroMod basin modeling of the generated oil from the Jurassic and Lower Cretaceous Formations fitted with the event of early galena generation, whereas the oil migration started before 70 m.y and continued to 30 m.y ago. Palynomorphs study confirms that the oil in source rocks is similar with the migrated oil

CHRONOSTRATIGRAPHICALLY BASED RESERVOIR MODEL FOR CENOMANIAN CARBONATES, SOUTHEASTERN IRAQ OILFIELDS

The Cenomanian – Turronian sedimentary succession in the south Iraq oil fields, including Ahmadi, Rumaila, Mishrif and Khasib formations have undergone into high-resolution reservoir-scale genetic sequence stratigraphic analysis. Some oil-wells from Majnoon and West-Qurna oil fields were selected as a representative case for the regional sequence stratigraphic analysis. The south Iraqi Albian – Cenomanian – Turronian succession of 2nd-order depositional super-sequence has been analyzed based on the Arabian Plate chronosequence stratigraphic context, properly distinguished by three main chrono-markers (The maximum flooding surface, MFS-K100 of the upper shale member of Nahr Umr Formation, MFS-K140 of the upper Mishrif carbonates, and MFS-K150 of the lower Khasib shale member).Three 3rd-order genetic mega-sequences were embraced between the cited chrono-markers. The markers have been considered as regional key-surfaces for the Late Albian – Cenomanian to Early Turonian and Late Turonian to Early Coniacian stratigraphy of the south Iraqi oil fields. Eight 4th-order genetic meso-sequences (MS1 to MS8) have been established, comprising multiple 5th-order high-frequency (HF) lithofacies cycles, successively arranged in the mega-sequences without disturbance. MFS-K135 (this study), MFS-K140, MFS-K150 and Seven successive regional chrono-markers [MFS-K120, MFS-K125 (this study), MFS-K130, and MFS-K160 of upper Khasib shale member] started from lower Ahmadi shale member, identify these meso-sequences. Associated fifteen key-surfaces (K121, K122, K123, K124, K125, K126, K127, K128, K129, K131, K132, K133, K134, K141 & K142) have been described as well. The meso-sequence 1 signifies Ahmadi lithofacies buildups, whereas; the other meso-sequences represent Mishrif lithofacies buildups. The Rumaila carbonates come across the first HST-unit of the meso-sequence 2. The meso-sequence 8 represents the Khasib carbonate facies buildups. The depositional super-sequence is terminated by type-1 sequence boundary SB-K150 at the top of the Mishrif Formation, created by maximum regression (MR). The study declares 15 reservoir syn-layers and 9 non-reservoir layers; each is essentially characterized by HF-single-lithofacies-cycle and lateral continuity pattern. This syn-layer model can be used as sequence steering technique for carbonates heterogeneity aspects, in the south Iraqi oil fields to control fluid dynamics in primary and secondary development projects

A MODIFIED WATER INJECTION TECHNIQUE TO IMPROVE OIL RECOVERY: MISHRIF CARBONATE RESERVOIRS IN SOUTHERN IRAQ OIL FIELDS, CASE STUDY

A modified water injection technique has organized by this study to improve oil recovery of the Mishrif reservoirs using polymerized alkaline surfactant water (PAS-Water) injection. It is planned to modify the existing water injection technology, first to control and balance the hazardous troublemaker reservoir facies of fifty-micron pore sizes with over 500 millidarcies permeability, along with the non-troublemaker types of less than twenty micron pore sizes with 45 to 100 millidarcies permeability. Second to control Mishrif reservoirs rock-wettability. Special core analysis under reservoir conditions of 2250 psi and 90 °C has carried out on tens of standard core plugs with heterogeneous buildup, using the proposed renewal water flooding mechanism. The technique assures early PAS-water injection to delay the water-breakthrough from 0.045 – 0.151 pore volumes water injected with 8 – 25% oil recovery, into 0.15 – 0.268 pore volumes water injected with 18 to 32% improved oil recovery. As well as, crude oil-in-water divertor injection after breakthrough, within 0.3 to oil0.65 – 0.85-pore volume of water injected to decrease water cut 1 four 0 to 15%. The overall progress of the PAS-water injection has achieved residual oil mobility of 65%, and upgraded the 35 – 50% oil recovery range by less than three pore volume water injected with 20 – 60% water cut, compared with the same oil recovery range by more than ten pore volume water injected with around 70% water cut. The ultimate oil recovery improved by this technique is from 70% via more than 20 pore volume water injected with over 95% water cut by usual water injection, to 85 – 90% via 6.4 pore volume water injected with over 90% water cut by the modified water injection. The technique succeeded to lower the end-point mobility ratio to 1.5 from above five by usual water injection. It is highly recommended to use ten micron mesh filter at the main injection site and four or five micron mesh filter at the injector sites; to avoid more than 80% of the suspended particles and save as much as possible the overall reservoir facies from permeability damage

Chemical, physical characterization and salinity distribution of the oilfield water in the Upper Sandstone Member of the Zubair reservoir at Rumaila North Oilfield, Southern Iraq

The oilfield water in the Upper Sandstone Member of the Zubair reservoir (Barriemian-Hauterivian) at Rumaila North Oil Field was investigated for the interpretation of salinity and geochemical evolution of brine compositions. The interaction of the oilfield water with reservoir rock resulted in a brine water derived from the marine water origin of partial mixing with meteoric water similar to the compositional ranges of formation water from Gulf of Mexico offshore/onshore Mesozoic reservoirs. The high TDS (207350- 230100; average 215625 mg/L) is consistent with the electrical conductivity (340362-372762; average 351024μs), and predominantly represented by Cl (123679 mg/L) as anions and (29200 and 14674 mg/L) for Na and Ca as cations respectively. The contribution of cation (epm%) are as Na (70.2), Ca (18.9), Mg (8.1) and K (1.7); and anion as Cl (99.7), SO4 (0.25), HCO3 (0.07) and CO3 (0.005). sodium (57550-60500mg/L) is greater than of seawater six times, calcium and magnesium three times greater, and chloride 6.5 times greater, but Sulfate is depleted to six times less due to a sulfur release from sulphates and link with different hydrocarbon species, precipices as native sulphur and link with hydrogen forming H2S. The Zubair oilfield water is characterised by acidic pH (pH=5.2- 5.77) enhanced petrophysical properties, high specific gravity (1.228) predicts a high fluid pressure (4866 psi), hydrocarbon saturation (0.43%), water saturation (0.57%) and porosity (12.7). The Mineral saturation model indicates that the Zubair oilfield water is an unsaturated water with respect to all suggested minerals at 5.45, but at simulated pH, brucite being an equilibrium at pH 9.12, but brucite and portlandite being supersaturated at pH 11.9. The mineral solubility responses to the changes in temperature, pressure, pH, Eh, and ionic strength, thereby formation damage is proportionally developed