Organic Matter Richness Research Articles

Deciphering the Roles of Molecular Weight and Carboxyl Richness of Organic Matter on Their Adsorption onto Ferrihydrite Nanoparticles and the Resulting Aggregation.

The aggregation behavior of ferrihydrite nanoparticles (FNPs) can control the fate of associated aqueous contaminants, trace elements, and organic compounds. However, FNP aggregation is difficult to predict in the presence of organic matter (OM), given the heterogeneity in the OM properties. Five model OMs based on (poly)acrylic acid (PAA or AA) and polyethylene glycol with or without terminal carboxyl groups (PEG or PEGbis, respectively) were chosen to probe the influence of key OM properties─specifically, carboxyl richness and molecular weight (MW)─and the dominant mechanisms by which they influence OM adsorption onto FNPs and the resulting aggregation. For OMs with similar MWs, those with a higher carboxyl richness adsorbed more extensively onto FNPs: PAA2k > PEGbis > PEG. Meanwhile, for OMs with the same carboxyl richness, higher MW OMs adsorbed more: PAA25k > PAA2k > AA. Furthermore, the subsequent aggregation of FNPs was largely controlled by the adsorbed mass. OMs with negligible adsorption (i.e., PEG and AA) did not change the aggregation behavior of FNPs. For OMs with low carboxyl richness (PEGbis), accelerated aggregation occurred through a bridging effect with low adsorbed mass. For OMs with high carboxyl richness (PAA2k and PAA25k), aggregation was accelerated at moderate adsorbed OM masses by patch-charge attraction and was inhibited with high adsorbed OM mass due to steric repulsion. This study provided new insights into understanding and predicting the transport and fate of FNPs and natural organic matter (NOM) in natural environments with various NOM compositions.

Richness, types, and thermal maturation of organic matter of Jurassic to Eocene rocks of the offshore Coastal Basin, Tanzania

Richness, types, and thermal maturation of organic matter of Jurassic to Eocene rocks of the offshore Coastal Basin, Tanzania

Palynostratigraphy of the Mississippian-Pennsylvanian boundary in the Tyler Formation, Williston Basin, USA: Implications for organic matter-rich source rocks and paleoenvironmental reconstruction

The Carboniferous was a period of intense environmental perturbations, climate changes between greenhouse and icehouse, eustatic sea level change, and accumulation of organic carbon-rich sediments. At this time, the Tyler Formation was deposited in the midcontinent USA. A detailed palynological analysis of the Tyler Formation revealed a highly diverse assemblage of spores with minor pollen content, represented by 100 species belonging to 51 genera. Stratigraphically constrained spores and pollen grains were used to construct three interval zones of middle-late Chesterian (late Viséan-Serpukhovian) to early Morrowan (middle Bashkirian) ages. The stratigraphic position of the Mississippian-Pennsylvanian boundary was determined in the lower Tyler Formation based on the last appearance of typical forms of the late Chesterian, including Tripartites vetustus, Knoxisporites triradiatus, Knoxisporites stephanephorus, Densosporites diatretus, and Schopfipollenites acadiensis, compared to the first appearance of early Morrowan Crassispora kosankei, Cirratriradites saturnii, Radiizonates aligerens, and Raistrickia saetosa. Palynofacies analysis and statistical clustering of the Tyler Formation showed three palynofacies assemblages. PFA-1 showed moderate relative abundances of phytoclasts and AOM, suggesting deposition close to fluvio-deltaic and shallow marine environments, while PFA-2 exhibited high abundances of phytoclasts, mostly of opaque wood, reflecting deposition in active river-dominated delta plains. PFA-3 showed the highest abundances of AOM, suggesting deposition in a shallow marine environment. Organic petrography and geochemistry data indicate that the Tyler Formation is one of the best source rock intervals throughout the midcontinent USA. Based on organic matter richness, the Tyler Formation is subdivided into three groups. The first group has TOC contents higher than 10 wt% of kerogen Types III, mixed II/III, and II with excellent hydrocarbon generation potential. The second group has TOC content in the range of 2–10 wt% of kerogen Types III, mixed II/III, and II, and fair to excellent hydrocarbon generation potential. The third group shows organic matter richness with TOC content below 2 wt% with good organic matter richness and kerogen Types III to IV, and poor to fair hydrocarbon generation potential. The organic matter thermal maturity is evaluated based on Tmax and VRo% values, suggesting that all samples of Tyler Formation are in the early to late stages of the oil window. However, care should be considered when assessing a mature source rock because the kerogen typing and generation is based on present-day TOC, S2, and HI rather than their original values.

Source rock assessment and organic matter characterization of the Oligocene upper Shahejie and Dongying formations in the Nanpu depression of the saline lacustrine Bohai Bay basin, China: Geochemical, palynological, and mineralogical perspectives

The Bohai Bay Basin, located in eastern China, is a significant petroliferous, non-marine rift basin, underwent intricate tectonic activities throughout the Cenozoic. The Nanpu Depression in the Huanghua sub-basin in the northern part of the basin was controlled by Paleogene rifting and increased subsidence. These geological processes resulted in the deposition of the Shahejie and Dongying formations, which exhibited varying quantities and qualities of organic matter. Eighty drill cuttings samples of the Paleogene First Member (Es1) and the overlying Third (Ed3) and Second (Ed2) members of the Shahejie and Dongying formations, respectively, were investigated. An integrated approach including organic and inorganic geochemistry, palynology, and mineralogy was employed to assess the paleoredox and marine incursion conditions, source rock quality and levels of thermal maturity, and factors that governed organic matter accumulation. Results indicated that the Es1 Member was deposited under anoxic conditions, resulting in the accumulation of organic matter-rich mudstones in the Nanpu Depression. Abundant pollen grains and acritarchs were found in the Es1 Member yielded along with minor occurrences of dinoflagellate cysts, freshwater algae, and spores. Terrestrial palynomorph composition provided evidence of increased terrestrial runoff, while the high abundance of acritarchs, accompanied by some dinoflagellate cysts, confirmed episodes of marine incursion and deposition under hypersaline conditions in the lacustrine Bohai Bay Basin. The Ed2 Member exhibited poor to fair amounts of organic matter and a limited potential of hydrocarbon generation with a variety of kerogen Types, including IV, III, II/III, and II. The Ed3 Member shows fair to good organic matter richness and hydrocarbon potential of kerogen Types III, II/III, and II. The Es1 Member emerged as the most promising source rock within the studied interval, boasting good to excellent organic matter richness, and fair to good hydrocarbon generation potential of kerogen Types III and II/III. Evaluating the thermal maturity of organic matter, based on Tmax and VRo-Eq% and related cross-plots, revealed that the Shahejie and Dongying formations are still in the immature to the early stage of the oil window. The mineralogical composition of the Es1 Member primarily consists of clay and quartz with some carbonate and accessory minerals, such as epigenetic halite, dolomite, and plagioclase. Weak correlations observed between the total organic carbon (TOC) and mineral components indicated that the availability of organic matter was primarily controlled by enhanced production and preservation rather than limited dilution under saline lacustrine, oxygen-deprived, and well-stratified water column conditions. Regional investigations of the Es1 Member confirmed the widespread anoxia and deposition of organic-rich source rocks in the Bohai Bay Basin during the Oligocene.

Unconventional hydrocarbon prospectivity of the Paleoproterozoic Fraynes Formation in Manbulloo S1, Northern Territory

The Paleoproterozoic Fraynes Formation in the Birrindudu Basin is a chronostratigraphic equivalent to the prospective Barney Creek Formation in the McArthur Basin and yet a comparable understanding of its source potential is lacking. As part of Geoscience Australia’s Exploring for the Future program, this study aims to assess the hydrocarbon generating potential and shale gas prospectivity of the Fraynes Formation in the exploration drill hole Manbulloo S1 through the reconstruction of the original source-rock characteristics and well log interpretation. Internal units inside the Fraynes Formation were defined according to sedimentary facies. The hydrocarbon generation potential was estimated from the calculated original total organic carbon content, hydrogen index and thermal maturity data measured from bitumen reflectance data. The shale total porosity was re-interpreted from bulk density logs by removing the organic matter effect, adding organic porosity for the organic-rich shales, and updating the water saturation. The maximum amount of gas generated from the organic-rich source rocks is 3969, 2769 and 1912 Mcf/a-ft assuming the kerogen compositions of 100% Type I, mix of 50–50% Type I and II, and 100% Type II, respectively. The richness of organic matter and interpreted water saturation (<100%) imply favourable shale gas prospectivity in the Fraynes Formation. This work expands our knowledge on the potential unconventional energy resources in the west of the greater McArthur Basin.

An integrated geomechanical and petrophysical multiparameter approach for gas reservoir evaluation

Integrating petrophysical and geomechanical parameters is an efficient approach to evaluating shale gas reservoir potential. The high cost of corings and their limited number, coupled with time-intensive investigation, led researchers to use this alternative combination approach. In the Jiaoshiba area, from single-pilot well core data and log measurements, petrophysical and geomechanical parameters such as shale volume, total organic carbon, gas content, as well as pore pressure, stress components, and mineral brittleness were first estimated using established methods. In the second phase, based on logging curves, the reservoir electro-facies (EF) classification was performed using the unsupervised multi-resolution graph-based clustering method on a series of twenty wells, identifying five EF with different intrinsic characteristics. Unsupervised analyses were developed using the multilayer artificial neural network while incorporating the K-nearest neighbors and graphical classification algorithms. The results from the first and second phases indicate reservoir richness in organic matter, with the best reservoir exhibited by EF2 and EF3. In addition, effective stress components (SV, SH, and Sh) evaluation shows a normal stress regime with hydraulic fracture systems perpendicular to the minimum horizontal stress at each measured depth of the reservoir (Sv > SH > Sh). This research workflow can efficiently evaluate shale reservoirs with a realistic approach for identifying favorable fracturing positions while reducing errors due to human interference.

Assessment of Edaphic conditions in the Mozogo-Gokoro National Park (Sudano-Sahelian zone of Cameroon)

Vegetation health and vitality are generally dependent on soil quality. This concept particularly integrates the capacity of soils to ensure suitable conditions for plant growth. Soil physico-chemical analyses were used to make this qualitative assessment in Mozogo-Gokoro National Park. Litter and composite soil samples were collected at different depths from 0 to 150 cm in three collection units (CUs) established in the park vegetation. The results showed that throughout the park, soils have physico-chemical characteristics favourable to plant productivity, particularly in the surface horizons of the CUs, which correspond to dense to clear dry forests and gallery forests. It was particularly observed that there was an abundance of litter, good soil aggregate stability extending to depth, organic matter richness, and medium-to-high cation exchange capacities. Richness in available phosphorus, near-neutral pH water throughout the profile, textures conducive to water percolation and rooting, and absence of salt toxicity were seen as other fertility traits. However, the potential acidity and high C/N ratios confirm the fragility of these soils. These soil characteristics may also be moderately nuanced in the most savannah CU, exhibiting qualitative changes in soil samples from surface to depth. These physico-chemical attributes contrast significantly with those of natural ecosystems with degraded pedological types in the Sudano-Sahelian region, indicating a conservation of resilience in interaction with the vegetation.

Application of Effluent from Anaerobic Digestion of Biomass to Condition the Soil: A Review of the Literature

Literature Review: Anaerobic digestion technology has significant potential in the treatment of organic waste, with varying levels of efficiency depending on the approach taken to the process. In addition to biogas production, it is also possible to obtain the digestate from anaerobic digestion, a nutrient and carbon-rich product, which is a relevant source for soil biota and fertility. Applying digestate to the soil helps in the recovery of degraded and contaminated areas due to its richness in nutrients and organic matter. When applied, it initiates the colonization of plants, colonies of fungi and bacteria, mineralizes nutrients, and promotes environmental recovery. Anaerobic digestion, when integrated with other processes such as composting, gasification, and pyrolysis, can enhance the capacity to sequester carbon in stable forms in the soil, thus reducing greenhouse gas emissions and increasing the potential for biomass (raw material) energy utilization. Study Objectives: To review the existing literature regarding the application of digestate as a soil conditioner and its benefits to plants (crops). Materials and Methods: Original articles related to the application of digestate in soil were selected through a search on the Web of Science and Science@Direct databases from the CAPES periodical portal. Conclusion, Results, and Implications: The selected articles present results indicating that digestates can be used as soil conditioners, leading to increased organic matter, microbial activity, nutrients, physical quality, and plant benefits, thus contributing to the circular economy. However, there is a need for further studies related to the agronomic responses of digestate application to plants.

Determination of in situ hydrocarbon contents in shale oil plays: Part 3: Quantification of light hydrocarbon evaporative loss in old cores based on preserved shales

Petroleum resource assessment obtained from laboratory tests on old core samples shelved in the open environment tend to underestimate in situ resources. Therefore, hydrocarbon loss and its restoration need to be investigated. The hydrocarbon loss was studied via the difference of programmed pyrolysis parameter (Rock–Eval derived S1) between preserved/fresh cores and their replicas that had been long-term exposed to ambient conditions. However, the in situ hydrocarbon potential is still seemed to be underestimated, because the effect of sample crushing and crucible waiting on pristine S1 detection did not receive enough attention. To solve this issue, 50 preserved shale core samples with Ro from 1.00% to 1.51% were collected from the K1qn1 Formation of northern Songliao Basin, Eastern China. All the samples were subjected to four parallel experiments: Dean–Stark extraction and nuclear magnetic resonance (NMR) T1–T2 mapping, using large rock pieces 3–5 cm in size, and thermal desorption gas chromatography (TD–GC) and Rock–Eval analysis, using 60-mesh powdered samples. In addition, a time series of TD–GC and Rock–Eval analyses were conducted on a preserved shale sample to investigate hydrocarbon loss during sample crushing, Rock–Eval crucible waiting process, and elapse-time exposure to the open environment. Rock–Eval pyrolysis was also conducted on one month-exposed shale cores and solvent-extracted samples. The results show that the total hydrocarbon content of large rock pieces is significantly greater than that of powdered samples. Sample crushing or grinding leads C8− light hydrocarbons to evaporate, and results in a loss of approximately 35% of S1. Rock–Eval crucible waiting process causes C14− hydrocarbons to evaporate, and results in an additional 25% loss of S1. To compensate for the sample crush induced S1 loss, an exponential distribution model was proposed based on the C8+ hydrocarbons in the TD–GC S1 fingerprints. Sample maturity, pristine light hydrocarbon (C14−) proportions, organic matter richness, and oil-bearing pore size primarily control the hydrocarbon loss of old shale samples. The higher the proportion of C14− and the lower the abundance of organic matter, the higher the amount of hydrocarbon loss. Finally, S1 restoration coefficient charts for large rock pieces and powdered samples with Ro ranging from 1.00% to 1.42% are provided. It highlights that previous studies have severely underestimated the in situ S1 when using the Rock–Eval method. This research has great implication for estimating in situ hydrocarbon potential using conventional coring samples.

Organic petrography and geochemistry of the Fu 2 member of the Paleocene Funing formation, Gaoyou Depression, Subei Basin, Eastern China: Implications for shale oil potential

The Fu 2 Member of the Paleocene Funing Formation in the Gaoyou Depression, Subei Basin is an organic matter-rich formation, and has a high potential for shale oil exploration and exploitation. Total organic carbon (TOC), organic petrography, Rock-Eval pyrolysis, chloroform bitumen “A” extraction, and SARA (saturates/aromatics/resins/asphaltenes) composition analyses of shale samples from one drill core in the studied area spanning a thickness of 257 m were conducted to study the organic matter (OM) richness, kerogen type, maceral composition, hydrocarbon generation potential, and oil content of the Fu 2 Member. Results show that the Fu 2 Member shales in the study area have a Ro of 0.87%, in the peak oil window, suggesting a high potential for hydrocarbon generation. The studied OM in shales mainly belongs to kerogen Type II, with a minor portion of Type I and Type III. Under microscopic observation, macerals in the studied shales are mainly composed of vitrinite, inertinite, alginite, and solid bitumen. The studied shales have an average TOC content of 1.41 wt%, indicating good petroleum potential. The variations of maceral compositions could affect the reliability when the Tmax is used as an indicator of thermal maturity. The lower Shale 4 and upper Shale 5 interval (3650–3700 m), with high TOC and high oil saturation index, is identified as the sweet-spot interval of the Fu 2 Member for shale oil exploration.

Petroleum Retention, Intraformational Migration and Segmented Accumulation within the Organic‐rich Shale in the Cretaceous Qingshankou Formation of the Gulong Sag, Songliao Basin, Northeast China

AbstractIn this study, organic geochemical and petrological analyses were conducted on 111 shale samples from a well to understand the retention, intraformational migration and segmented accumulation (shale oil enrichment in different intervals is unconnected) features of shale oil within the organic‐rich shale in the Qingshankou Formation of the Gulong Sag. Our study shows that retained petroleum characteristics in the investigated succession are mainly influenced by three factors: organic richness, intraformational migration and segmented accumulation. Organic matter richness primarily controls the amount of retained petroleum, especially the ‘live’ component indicated by the S2 value rather than the total organic carbon (TOC) figure alone. The negative expulsion efficiencies determined by mass‐balance calculations of hydrocarbons reveal that petroleum from adjacent organic‐rich intervals migrates into the interval of about 2386–2408 m, which is characterized by high free hydrocarbon (S1), OSI and saturated hydrocarbons content, along with a greater difference in δ13C values between polar compounds (including resins and asphaltenes) and saturated hydrocarbons. The depth‐dependent heterogeneity of carbon isotope ratios (δ13C) of mud methane gas, δ13C of extracts gross composition (SARA), δ13C of kerogen and SARA content of extracts suggest that the studied succession can be subdivided into four intervals. The shale oil sealing enrichment character in each interval is further corroborated by the distinct δ13C values of mud methane gas in different intervals. Due to the migration of petroleum into the 2386–2408 m interval, the S1, OSI and saturated hydrocarbons content of the interval show higher relative values. The maturity of organic matter in the 2471–2500 m interval is at the highest with the smaller size molecular components of the retained petroleum. Thus, favorable ‘sweet spots’ may be found in the 2386–2408 m interval and the 2471–2500 m interval, according to the experiment results in this study.

Lipid Biosignatures From SO4‐Rich Hypersaline Lakes of the Cariboo Plateau

AbstractModern and ancient hypersaline brines have been identified across the solar system, but the habitability of these environments remains unknown. Here, we evaluate organic matter (OM) production in MgSO4 and Na2CO3 rich hypersaline lakes whose chemistries resemble deposits on Mars such as those identified in Jezero crater. We focus our analysis on lipid biomarkers including fatty acids, alkanes, and ether‐bound lipids in modern brines, salt deposits, and surface sediments. We also report total organic carbon (TOC), carbon/nitrogen (C/N) ratios, and bulk OC (δ13C and δ15N) isotopes to contextualize the lipid biomarker data. In all lakes, the predominant biosignatures include midchain (12 < C < 23) fatty acids and alkanes suggesting microbial origin. Sediments also incorporate a greater diversity of lipids. Ether‐bound lipids derived from archaea and bacteria constitute a minor but measurable fraction of the lipids. This result contrasts with typical findings from other studies with NaCl brines which contain significant archeal biomass. TOC concentrations in all sediments are high, ranging from 0.7% to 12% with sulfate‐rich sediments having the highest concentrations. The isotopic and elemental compositions of TOC corroborate the biomarker results, showing δ13C values and C/N values indicative of aquatic microbial origin. This richness of organic matter and in situ microbial biosignatures differ from previously studied Cl‐dominated Mars‐analog sites which have shown limited OM production and preservation and acidic SO4‐rich hypersaline environments which were dominated by terrestrial inputs. Overall, our results suggest that MgSO4‐rich hypersaline environments are conducive for life and harbor a rich microbial biomarker landscape.

Geochemical Evaluation of the Lower Senonian Ogugu Shale, Southern Benue Trough, Nigeria: Implication for Source Richness, Quality and Petroleum Potential

The Lower Senonian Ogugu Shale is the topmost layer of the Coniancian-Santonian depositional unit in the Southern Benue Trough. Sediments of this unit have been suggested to have huge potential for hydrocarbon generation. However, detailed geochemical studies on the organic matter source, thermal maturity and the hydrocarbon potential Ogugu Shale are still missing. For the present study, a total of 16 cuttings and 3 core samples of the Ogugu Shale from Amasiodo-1 well were subjected to total organic carbon (TOC), Rock-Eval pyrolysis and gas chromatography mass spectrometry (GC-MS) analyses in order to characterize the organic matter richness, kerogen type and liquid hydrocarbon-generative potential in the samples. The TOC values (0.70 to 1.20 wt. %) and Rock-Eval pyrolysis data S2 (0.26-0.73 mg HC/g rock) as well as its calculated parameters Hydrogen Index (HI; 23-72 mg HC/g rock) and Generative Potential (GP; 0.33-0.84 mg HC/g rock) suggest poor to fair organic rich rock containing dominantly terrestrially derived Type III kerogen. The biomarkers as well as the source-indicating aromatic hydrocarbons in the samples suggest contributions from mixed aquatic and vascular organic matter deposited under oxic-dyoxic conditions of deltaic paleoenvironment. The Rock-Eval pyrolysis Tmax (434-4560 C) including the derived vitrinite reflectance (Rc; 0.65-1.05%) indicate thermally matured source rocks. The thermal maturity status of Ogugu Shale is further supported by molecular thermal parameters from the saturate and aromatic compounds. This study therefore conclude that that the Senonian Ogugu Shale of the Southern Benue Trough contain thermally matured fair quantity of organic matter with poor hydrocarbon potential.

Assessment of kerogen types and source rock potential of Lower Jurassic successions in the Mandawa Basin, SE Tanzania

Variability in organic matter types and quality of source rock intervals across evolving rift-basins has been the focus of previous studies, which have shown that due to dynamic sedimentary regimes and water depths such source intervals occur sporadically and restricted to specific stratigraphic horizons. Such heterogeneous settings require detailed geochemical analysis to document variations in source quality. This study presents a comprehensive geochemical analysis of source rock intervals in Lower Jurassic successions (Mbuo, Nondwa and Mihambia Formations) in the Mandawa Basin, on-shore Tanzania, in order to constrain organic matter types and quality. Organic matter richness was measured by Total Organic Carbon (TOC) analysis, while quality and thermal maturity of organic matter was assessed by programmed pyrolysis, complemented by organic carbon isotope analysis (δ13Corg) of sediment samples collected from outcrops, cores, and cuttings samples. TOC and programmed pyrolysis datasets from existing literature were synthesized in this study to better understand organic matter quality and thermal maturity evolution on regional scale. These data were examined in relation to paleogeography to gain insight into the factors regulating the distribution of organic matter quality within the Mandawa Basin.Average TOC contents in Lower Jurassic sediments fluctuate from 0.31 to 4.83 wt% with an average of 1.4 wt%, whereas, kerogen yield (S2) and hydrogen index (HI) remain generally low, with values ranging from 0.01 to 8.6 (mg HC/g rock) with an average (0.92 mg HC/g rock) as well as from 2 to 233 (mg HC/g TOC) with an average of 46 (mg HC/g TOC), respectively. Organic matter is composed mainly of type III (gas prone) to IV (inert) kerogens with lesser admixture of type II-III kerogen (oil-gas prone), which have been deeply buried and undergone a wider range of thermal diagenesis, from early to overmature stage. The δ13Corg isotopic composition of organic matter is consistent with kerogen typing, indicating terrestrial organic matter with a heavier signature during sea level low stands. Upon marine incursions δ13Corg shifts to isotopically more depleted marine organic matter. This implies that the investigated source intervals have poor to fair source potential. Only a few intervals of limited thickness in the Upper Mbuo, Nondwa, and Mihambia Formations of the Mita Gamma-1 and East Lika-1 wells, as well as in the Lower Mbuo Formation in the Mbuo-1 well, have been locally enriched. The enrichment is attributed to periodic marine ingressions that have persisted since the Pliensbachian period and suggests the presence of oil generation potential.A comparison of TOC and programmed pyrolysis borehole data from this study to those compiled from literature in a paleogeographical context reveals high spatial variability. The southeastern and northwestern parts of the study area have the highest source potential, indicating high organic matter productivity in the dysoxic to anoxic water column, which promoted the preservation of organic matter. In contrast, the eastern and western parts generally show low source potential, indicating degraded organic matter and significant terrestrial influxes from emergent land that were deposited in shallow, mixed oxygenated water with low to moderate organic matter productivity.

Unraveling the impact of dissolved organic matter on arsenic mobilization in alluvial aquifer of the lower Yellow River basin, Northern China

Increased exposure to arsenic (As) has been reported in many arid and semi-arid areas, where drinking water and agricultural irrigation strongly rely on groundwater. High-As groundwater occurred widely in the Northern Henan Plain, which belongs to the lower Yellow River alluvial plain area, posing a new threat to the health of local residents. Based on 77 groundwater samples collected from different hydrogeological units, the sources and optical characteristics of dissolved organic matter (DOM) components in groundwater were analyzed using a three-dimensional fluorescence spectroscopy excitation-emission matrix (3D-EEM) and parallel factor analysis (PARAFAC), to reveal the influence of organic matter on As mobilization and enrichment in Quaternary alluvial aquifers. The results showed that high-As groundwater was concentrated in the areas of the piedmont alluvial depressions and the Yellow River crevasse splay, which was closely related to the richness of organic matter in the buried sediments of the Yellow River paleochannels. Vertically, the variability of groundwater As was governed by the redox conditions and anthropogenic activities, leading to elevated As levels in deep aquifers. High-As groundwater was characterized by high content of humic-like components (C2+C3), strong humification, and weak authigenic sources, which can be attributed to the effects of frequent diversion of the Yellow River and the introduction of more terrestrial humic-like components by intensive agricultural activities (e.g., irrigation). The significant correlations between Fe2+ and As and NH4+ (r = 0.65, 0.48, p < 0.05) as well as the maximum fluorescence intensity of C2 and C3 with As (r = 0.59, 0.74, p < 0.05) reflected the dominant impact of DOM on As migration. The terrestrial-derived high molecular weight organic matter C2 facilitated As mobilization through complexation reactions, while the labile humic-like component C3 triggered the reductive dissolution of iron oxides/hydroxides through microbial metabolic processes, which together contributed to the enrichment of As in groundwater from the Northern Henan Plain.

Valorization of Baker Yeast Industry Waste in Agriculture by Improving Germination and Growth of Barley and Pea.

Industrial waste still present an environmental danger for the nature and survival of all living beings. Among these toxic products, the focus has been on liquid effluents from the baker's yeast industry that cause real environmental problems mainly due to their pollutant load and the release of unpleasant odors. In order to minimize these hazards and to take advantage of these wastes for the sake of our environment, the present work consists on valorizing effluents from the baker's yeast industry on barley (Hordeum vulgare) and pea (Pisum sativum), two important agricultural products of Tunisian north-west. Results showed that this waste is characterized by its richness in organic matter, and the presence of proteins traces with high chemical and biochemical oxygen demand (COD and BOD5) values. Diluted effluent at a dose of 2.5mg/g significantly improves germination of both plant seeds by germination index (GI) calculation, to reach a maximum of 190 ± 17% and 150 ± 14% for barley and pea, respectively. In fertigation experiment, the use of a lower dose of .62mg/g of diluted effluent promotes plant length to reach 52 ± 4cm and 45 ± 1.4cm, respectively, for H. vulgare and P. sativum. Gas chromatography coupled to mass spectrometry (GC-MS) analysis after derivatization showed significant enhancement of auxin production in pea treated with .62mg/g of cream compared to control with a concentration of 10.60 ± .81 and 8.16 ± .43ng/gFW, respectively. In another experiment, the irrigation of pea plants with furfural, as major compound of cream, promotes length and auxin production to reach 9.89 ± .56ng/gFW for a furfural dose of .31mg/g. This leads us to valorize baker's yeast effluent as an environment-friendly natural product in pea and barley agricultural and give insight to its mode of action.

Oil Mobility Evaluation of Fine-Grained Sedimentary Rocks with High Heterogeneity: A Case Study of the Lucaogou Formation in the Jimusar Sag, Junggar Basin, NW China

The oil mobility in unconventional tight/shale oil reservoirs is complex because of the high heterogeneity in the matrix pore structure and connectivity. Thus, it is difficult to evaluate hydrocarbon exploration potential precisely. In this study, multistep temperature pyrolysis (MTP) Rock-Eval and 1D (dimensional) as well as 2D nuclear magnetic resonance (NMR) techniques were employed to systematically characterize the oil mobility in lacustrine fine-grained sedimentary rocks from the Lucaogou Formation in the Jimusar Sag, Junggar Basin, NW China. The results show that the Lucaogou Formation fine-grained sedimentary rocks can be subdivided into six types of lithofacies. With the increase of organic matter richness, the content of adsorbed oil increases, whereas the content of movable oil increases first and tends to stabilize (when total organic carbon (TOC) > 4%). This is because when TOC is low, the fine-grained sedimentary rocks need to self-adsorb before oil production; when TOC increases further, the generated oil will break through the absorption limit and charge into the adjacent reservoirs; therefore, the movable oil ceases to increase. Permeability is found to have a greater impact on movable fluid saturation than porosity. Meanwhile, good throat radius and pore connectivity are conducive to oil flow as movable oil is more sensitive to throats rather than pores. Furthermore, a higher content of brittle minerals is not necessarily favorable for oil flow; alternatively, more clay minerals are easy to from cements causing pore blockage, which will essentially hinder oil mobility. Overall, the organic matter content, reservoir pore structure, and rock mineral composition are the main factors affecting tight/shale oil mobility. On the basis of the above research, a conceptual model of oil mobility in different lithofacies’ reservoirs is established. These results have a reference significance for evaluating oil recoverability in fine-grained sedimentary rocks.

Prediction of fluid oil and gas volumes of shales with a deep learning model and its application to the Bakken and Marcellus shales

The fluid oil and gas volumes (S1) retained within the shales are one of the most important parameter of producible fluid oil and gas saturations of shales together with total organic carbon content. The S1 volumes can directly be obtained by Rock-Eval pyrolysis analysis. However, it is time consuming and not practical to obtain samples from all intervals of all wells in any shale play. S1 volumes prediction with a deep learning (DL) model have increasingly became important with the booming exploration and development of shale oil and gas resources. S1 volumes of shales are controlled by organic matter richness, type and maturity together with reservoir quality and adsorption capacity which are mainly effected by age, depth, organic content, maturity and mineralogy. A dataset consisting of 331 samples from 19 wells of various locations of the world-class organic-rich shales of the Niobrara, Eagle Ford, Barnett, Haynesville, Woodford, Vaca Muerta and Dadaş has been used to determination of a DL model for S1 volumes prediction using Python 3 programing environment with Tensorflow and Keras open-source libraries. The DL model that contains 5 dense layers and, 1024, 512, 256, 128 and 128 neurons has been predicted S1 volumes of shales as high as R2 = 0.97 from the standard petroleum E&P activities. The DL model has also successfully been applied to S1 volumes prediction of the Bakken and Marcellus shales of the North America. The prediction of the S1 volumes show that the shales have lower to higher reservoir quality and, oil and gas production rate that are well-matches with former studies.

Source-rock potential and paleoenvironment of the Coniacian Numanha Formation, northeastern Nigeria: An integrated palynofacies and geochemical approach

A study of source-rock characterization and paleoenvironmental interpretation has been carried out on a relatively thick Coniacian sedimentary succession from the Numanha Formation in the Guyuk area of the Yola arm in the Northern Benue Trough, northeastern Nigeria. The aim is to provide organic facies data for the assessment of its hydrocarbon generating potential owing to the high prospects of its lateral equivalent Fika Shale in the Gongola arm of the Northern Benue Trough. The investigation of 98 samples from three outcrop sections [09° 50′ N, 11° 51′ E; 09° 54′ N, 11° 50′ E; 09° 54′ N, 11° 49′ E] which includes palynofacies analysis, spore/pollen coloration, and geochemical analyses enabled an evaluation of organic matter richness and quality. Measured TOC ranges between 0.01 and 7.4% which reflects poor to good organic richness, while visual kerogen characterization shows thermally mature Type II-III kerogen indicative of oil and gas prone materials. Recovered palynomorphs comprised both marine (dinoflagellate cysts, microforaminiferal test linings) and terrestrial (spores, pollen, freshwater alga Pediastrum) taxa. These palynomorphs vary in proportion at different horizons of the sections indicating shoreline fluctuations. Except for the Kurnyi section, amorphous organic matter occurs in minor percentages, indicating low preservation potential during deposition. All data indicate that the Numanha Formation was deposited in a highly proximal to mud-dominated oxic shelf environment.

Organic matter accumulation in lacustrine shale of the Permian Jimsar Sag, Junggar Basin, NW China

The lacustrine organic-rich shale in the Permian Lucaogou (LCG) Formation of the Jimsar Sag, Junggar Basin, is one of the main shale oil plays in China. In this paper, geological and geochemical research techniques were employed to evaluate the geochemical variability of the lacustrine shale and the production of organic matter and its preservation conditions. The LCG Formation is characterized by its complex mineral compositions and a wide range of organic matter richness and quality. The presence of high proportions of β-carotane and C29 steranes, indicates that the organic matter mainly originated from phytoplankton and aquatic algal-bacterial organisms, especially cyanobacteria. This study found that the productivity of the Lower LCG Member (P2l1) was highest, and the Middle LCG Member (P2l2) was the lowest. During the deposition of the Lower LCG Member, the lake's bottom water was predominantly a reducing environment, and the degradation of organic matter was largely a result of bacterial sulfate reduction. During the deposition of the Middle and Upper LCG members, the lake's bottom water was mainly oxidizing, and the degradation of organic matter was likely to be caused by aerobic processes. Based on a comprehensive analysis of the origin and production of organic matter, as well as its depositional environment and preservation conditions, two organic matter accumulation models were proposed to explain the distribution of the organic-rich shale. In model A, the high influx of volcanic ash released nutrients and brought abundant sulfate into the water, the accumulation of organic matter was mainly controlled by the preservation of organic matter, which was mainly controlled by BSR. In the model B, the influx of volcanic ash was small, organic matter was mainly degraded by oxygen and the accumulation of organic matter is mainly determined by the production of organic matter.