Hasil untuk "Petrology"

Saeed Kamran, Ahmad Ahamadi Khalaji, Mehdi Rezaei-Kahkhaei et al.

IntroductionVolcanic rocks widely extended throughout the Earth's continental crust (Brilhante et al., 2024). Among the different tectonic setting, a group of igneous rocks is related to volcanic arc; these rocks, according to Tang et al. (2022), include a range of mafic-intermediate rocks with SiO2 (47.34-60 wt%), Fe2O3 (11.63-73.4 wt%) and Mg coefficient (26-66 wt%), remarkable chemical criteria are related to calc-alkaline series with medium to high potassium and LILE enrichment. Moreover, the Ce negative anomaly in these rocks is consistent with the subduction zone. In this paper, based on whole-rock chemistry data, the geochemical properties of volcanic rocks of the Ahovan area in northeast of Semnan (Central Iran) are investigated. The main purpose of the present paper is the study of tectonic setting as well as the tectonomagmatism of these rocks.Analytical MethodsDuring the field studies, 80 samples were collected from the volcanic rocks for petrographic observations. Following the preparation of thin sections, their mineralogy and textural relationships were carefully considered, and 10 of them with least alteration were sent to the ALS-CHEMEX laboratory in Canada for identification of major elements by ICP-OES and trace and rare earth elements by ICP-MS (Table 1). Furthermore, 11 samples of the Khalatbari-Jafari and Etesami (2018) were used in this study for comparison The measurement accuracy for all major elements was 0.01%w.t, the maximum measurement accuracy in the trace elements for Cr, Li, and Tl was 10 ppm and for Cs, Ho, Lu, Tb, and Tm was 0.01 ppm.Petrography According to field studies, the Eocene volcanic units, trending east-west, are much more widespread than the intrusive rocks of Ahovan area. These units have a mixed spectrum of basalt, trachyte and andesite-trachyandesite, which the latter rocks cover a large volume.The basaltic rocks, with gray and black in color, are dominated by the presence of plagioclase and clinopyroxene as the main minerals. The white and grayish white andesite-trachyandesite are characterized by the occurrence of plagioclase, clinopyroxene, amphibole and biotite as well as porphyry and microlithic porphyry textures. Trachyte rocks are white and grayish white in hand spacemen. Plagioclase and sanidine as phenocrysts and microlites constitute the main minerals of the trachyte rocks. Amphibole and biotite are small amounts in these rocks (10 vol.%). Iron oxides, calcite, chlorite and epidote are the alteration products of these minerals. Dolerite dykes, trending N-S and a maximum thickness of 2 m crosscut all the volcanic rocks. under study.GeochemistryThe overall petrographic and geochemical data point to the nature of calc-alkaline to high-potassium calc-alkaline of the rocks studied, which are originated by the low-pressure melting of spinel lherzolite and developed at a depth less than the garnet stability field. In the Y versus Zr diagram, the study rocks are in the volcanic arc setting. The REE pattern of the study rocks normalized to chondrite follow the sloping pattern of calc-alkane rocks related to island arcs. In spider diagram of incompatible elements normalized to N-MORBs, the study rocks show LILE enrichment and HFSE depletion indicating the crustal contamination process involved in the formation of these rocks. The depletion of Nb, Ti and Ta show characteristics of arc islands. Moreover, LILE's enrichment such as K and Sr indicate that the rocks under study originated from the mantle metasomatism resulting from hydrous fluids penetrated from the subducting crust into the mantle wedge at different depths.ConclusionThe volcanic rocks of Ahovan area are dominated by the presence of basalt, andesite-trachyandesite and trachyte belonging to Middle-Late Eocene. A series of trachybasalt and basalt-trachyandesite dykes, trending north-south, and a maximum thickness of 2 meters, crosscut the rocks of the area. The essential minerals of basalts are plagioclase and clinopyroxene and those of andesite-trachyandesite are plagioclase, clinopyroxene, amphibole and biotite. Plagioclase and sanidine are the dominant minerals of trachytes. In magmatic series diagram, all the rocks studied are in the range of calc-alkaline to high-potassium calc-alkaline series, originated from a relatively low-pressure melting of spinel lherzolite at a depth of lower than the garnet melting stability field. The Chondrite-normalized rare earth element (REE) patterns are similar to calc-alkaline rocks from island arc. Also, in the spider diagram of incompatible elements normalized to N-MORB, these rocks show enrichment in LILE and depletion in HFSE indicating the involvement of the crustal contamination process in formation of these rocks. The LILE enrichment (i.e., K and Sr) points to mantle alteration resulting from aqueous fluids penetrated from the subducting crust of the Neotethys ocean into the mantle wedge at different depths played a role in the formation of these rocks. In tectonic setting diagrams, the rocks under investigation are in the range of calc-alkaline basalts related to volcanic arcs.

Mohamed A. Khalifa, Bassem S. Nabawy, Mohamed F. Abu-Hashish et al.

Abstract Detection of the low resistivity-low contrast (LRLC) reservoirs is among the main challenges in the oil industry. In this concern, the LRLC pay zones of the Upper Messinian Abu Madi clastic reservoirs in the onshore Nile Delta Gas fields became a main challenge for significant exploration. This type of reservoirs, including low resistivity-low contrast zones and thin-bedded intervals, are often overlooked using the conventional petrophysical evaluation techniques, especially in the wildcat exploratory wells or highly agitated shoreline depositional environments like the Nile Delta of Egypt. These hidden low contrast reservoirs are generally challenging due to the presence of many shale intercalations/laminations and/or due to increasing the shale volume represented in the form of dispersed distribution, and the dominance of conductive clay minerals. Therefore, in this study, the expected high resistivity values of the gas-bearing reservoir intervals of the Abu Madi Formation in the onshore Begonia gas Field, as a typical case study of the LRLC reservoirs, are masked due to the relatively high shale conductivity, particularly when the thickness of these intervals is less than the vertical resolution of the utilized conventional resistivity log. To verify the LRLC phenomena of the Begonia gas Field, the obtained data was compared to the South Abu El Naga gas Field as a normal case study with a relatively high resistivity gas-bearing pay zone. To overcome the impact of the conductive clay mineral content and identify these hidden low resistivity reservoir intervals, it is necessary to integrate the conventional logging data (gamma-ray, shallow and deep resistivity, density, and neutron) with the acoustic log data including shear and compressional sonic data. In this way, a useful relationship can be established enabling the detection of these hidden LRLC reservoir intervals. This integration is based on the principle that shear waves are not influenced by the fluids types, whereas the compressional sonic waves are influenced by the reservoir fluids. However, to effectively investigate these concealed LRLC reservoir intervals, which can boost production and increase the potential reserves, it is essential to have a low water cut value. The present study represents introduces an efficient workflow, which can be extended to other similar LRLC pay zones in the Nile Delta and northeast Africa. It is also extendible to the LRLC reservoirs in similar deltaic systems having conductive minerals-bearing reservoirs or thin beds.

Philip I. Batanov, Ilyas F. Abkadyrov, Artem V. Degterev et al.

The paper provides information on the objectives, methods, targets and some preliminary results of the expeditionary work carried out within the framework of the RSF project No.21-17-00049 by the employees of the Institute of Volcanology and Seismology of the FEB RAS, Institute of Marine Geology and Geophysics of the FEB RAS, Pacific Geographical Institute of the FEB RAS and Trofimuk Institute of Petroleum-Gas Geology and Geophysics of the SB RAS in 2022 and 2023. The main objectives of the expedition were geological volcanological, hydrogeological, geophysical, tephrochronological, and paleoseismological studies. In accordance with the set objectives, field teams were formed, which began work in February 2022. On the basis of the data obtained during the expedition, previously unknown hydrothermal manifestations and seismic events on Iturup Island were identified. A number of geophysical and paleomagnetic surveys were carried out.

Alejandro Prieto, Paula Cristóbal, Javier Llamazares González et al.

The dataset presented here is the quartzite and quartz reference collection from the National Research Centre of Human Evolution of Spain (CENIEH), Burgos. This dataset or online lithotheque consists of 73 archaeological and geological samples obtained in different projects in which the CENIEH has been involved in the last 15 years. Most of the samples described here were collected from the Iberian Peninsula, while a few others were chosen from Eastern Africa. The samples have been petrographically described using thin section, stereomicroscopy and de visu petrographic observations and they have been characterised according to their petrogenesis. This dataset consists of a comprehensive report, an alphanumeric dataset with relevant features and an extensive picture archive. The dataset collection is stored at the CENIEH and it is open for researchers who want to use it for establishing their reference collection and describing quartzites in archaeological contexts.

Jane H. Scarrow, Matthew J. Pankhurst, Olivia A. Barbee et al.

We present an integrated petrological study of the 2021 Tajogaite eruption, La Palma, examining magmatic processes that initiated, sustained, and terminated surface volcanic activity. High temporal resolution sampling of near-continuously erupted alkali-basalt lava and tephra over the 85-day event reveals magma plumbing system dynamics from compositional trends. Initial deposits were mineralogically varied, reflecting mobilisation of shallow, evolved mush perturbed by fresh deep, primitive magma influx (Stage 1 - initiation). Transition to more primitive, uniform compositions recorded progressively deeper tapping of pre-existing magmatic zonation (Stage 2 - evacuation). The final stage (Stage 3 - waning) was characterised by more evolved magma compositions on the same fractionation trend as Stage 2, with tephra glass compositions suggesting a proportionately larger role of mush interstitial melts. We suggest this reflects shutdown of mantle-derived magma supply, a key process in eruption waning and termination, and compression-driven melt extraction of less mobile melts. Correlation with geophysical monitoring data demonstrates how near-real-time petrological monitoring could improve understanding of when an eruption may end.

Fei YANG, Zhichao SHEN, Jiangmin DU et al.

BACKGROUNDImproving the prediction ability of relatively high-quality reservoirs under tight backgrounds is a bottleneck and a challenge in current oil and gas exploration and development theories. For tight reservoirs, exploring the dissolution mechanism of organic acid fluids on the reservoir is particularly important. Previous researchers have conducted a large number of water rock reaction simulation experiments on the dissolution of organic acids leading to the formation of secondary pores. It is proposed that the dissolution effect of acidic fluids is the main factor for increasing porosity in tight reservoirs, and it is also a key way to find “sweet spots” in tight reservoirs[3]. Based on previous research on dissolution pores in sandstone, scholars have focused on studying the chemical mechanism of organic acids in the dissolution of carbonate and feldspar minerals. Some studies have shown that the dissolution of calcite requires a lower pH[19] and the acidity of binary acid is very strong, which can greatly improve the solubility of aluminosilicate minerals[20-22]. However, the heterogeneity of tight sandstone reservoirs is strong, and its complex mineral components and pore structure characteristics differ greatly; it has a higher content of clay minerals, and during the diagenesis process, clay minerals often precipitate on the rigid particle surface of the pore inner wall as authigenic minerals. The main mineral in contact with crude oil is of clay composition in dense sandstone reservoirs[23-25]. Chlorite, kaolinite, illite and other minerals are common and important clay mineral types. As important factors affecting reservoir exploration and development, their organic acid dissolution effects on clay minerals need to be further studied.OBJECTIVES(1) In order to explore the main influencing factors of organic acids on the dissolution of clay minerals in tight sandstone, by analyzing the influence of time, temperature and different types of organic acids on the dissolution of clay minerals. (2) To reveal the dissolution reaction mechanism between organic acid fluids and tight sandstone, providing a theoretical basis for improving the prediction ability of relatively high-quality reservoirs under tight backgrounds.METHODS(1) The Triassic Yanchang Formation in the Ordos Basin was selected as the research object, and the ratio of reaction fluid to sandstone dissolution simulation experiment was conducted according to the type and content of organic acid in the thermal evolution fluid of Source rock. (2) After the reaction, the column rock sample was rinsed multiple times with distilled water, placed in a drying oven, dried for 24h, and then taken out for testing. The porosity and permeability of the column rock sample after the reaction were tested on the PoroPDP-200 overlying pressure pore permeability meter before and after the experiment, and the intensity of dissolution was quantitatively calibrated. (3) Small samples of 5-8cm for argon ion polishing were selected, and observed under the Quanta450FEG field emission environment scanning electron microscope (Lanzhou Oil and Gas Resources Research Center, Chinese Academy of Sciences). Then, through thin section identification and scanning electron microscope observation of the petrology characteristics of the samples, the cement and pore characteristics of the samples before and after the experiment were compared. (4) Using Optima 8000 inductively coupled plasma-optical emission spectrometer (PerkinElmer Company, USA) to detect cations, the practical range of the measured standard curve was 0.1-20mg/L, and samples that were not within the test range were diluted. The standard curve solution contains a total of 8 ions: K, Ca, Na, Mg, Al, Si, P and Mn.RESULTS(1) With the increase of time (1-9 days), the increase of porosity dissolution increases first and then decreases, reaching its peak at 6 days; the increase of penetration rate shows a continuous growth trend. The increase in temperature can also promote the dissolution of sandstone by organic acids (Fig.3, Fig.4). (2) Different types of organic acids have selective dissolution of clay minerals. Tartaric acid mainly dissolves clay minerals, detrital feldspar and a small amount of calcite cement; on the contrary, acetic acid mainly dissolves calcite. The sequence of propionic acid dissolution is from calcite to feldspar detrital particles, from dissolution cement matrix to argillized feldspar; the mixed acid solution of formic acid, acetic acid and propionic acid and mixed acid solution of formic acid, acetic acid, propionic acid and tartaric acid preferentially dissolve chlorinated and argillized feldspar and calcite until calcite is completely dissolved (Fig.4, Fig.5). (3) The improvement of pores by formic acid is not significant among different types of organic acids. Propionic acid greatly improves porosity. The influence of combined acids on porosity is a comprehensive reflection of the influence of single acids (Fig.6).CONCLUSIONSFormic acid has little effect on porosity, whereas acetic acid and propionic acid have obvious effect on porosity. The combined effects of formic acid, acetic acid, propionic acid, and tartaric acid on porosity and permeability are a comprehensive reflection of the improvement of a single acid. The selective dissolution of clay minerals in tight sandstone by different types of organic acids has different effects on the physical properties of the reservoir, providing a scientific basis for improving the prediction ability of relatively high-quality reservoirs under tight background.

Guillem Gisbert, Valentin R. Troll, James M. D. Day et al.

Mohammad Reza Mansouri Daneshvar, Parviz Mansouri-Daneshvar, Reza Moussavi-Harami et al.

Abstract Despite the previous interpretations of the evolutionary scenarios of the Qatar Arch, the present study aimed to present a new complementary scenario to lay out the probable effects of another basement fault, corresponding to the physical shape of the Arch. A remote sensing study was carried out based on geological and geophysical data interpretations, obtained from some national and international databases, including GIS-based global geology data of Harvard University, the free-air gravity anomaly data from the World Gravity Map (WGM), and the airborne geophysical project of the National Geosciences Database of Iran (NGDIR). Results revealed that offshore extrapolation of the Trans Arabian-Bostaneh Fault (TABF) lineament through the morphological boundary of Hauterivian–Barremian (HB) formations and the offshore extrapolation of the Kazerun fault could produce a new complementary model for the Qatar Arch evolution. Based on the particular shape of the Arch (i.e., narrowing and uplifting to the south influenced by the Kazerun basement fault and the rotation of TABF), we can propose that these faults crossed each other after the Barremian age, created a particular shape of the Qatar Arch, and influenced beneath the Fars hinterland. The obtained geophysical gravity data also showed a good match between structural units and faults with maximum values corresponding to the Qatar Arch and minimum values relating to the thick sediment field in the Fars region. In conclusion, the present study contributes to a new proposition about exploring the possible faults and a new gas field situated in the interior territory of Iran. All of these interpretations will provide a new insight to improve the extant knowledge in the geology and petroleum evolution of the study area, such as the Plate tectonic events and the creation of possible reservoirs in future.

Xinchen Gao, Kangliang Guo, Peng Chen et al.

Abstract The closure fracture phenomenon increases the complexity of well testing and reduces the accuracy of productivity forecasts when tight oil reservoirs are exploited. However, most existing productivity models tend to ignore this. Therefore, a productivity prediction model for multi-fractured horizontal wells in tight oil reservoirs considering fracture closure has been developed by considering the stress sensitivity in the formation and combining the physical parameters of actual production. The model is solved by the Laplace transform, perturbation transform, Pedrosa transform, and Stehfest numerical inversion. Drawing productivity impact curves and discussing productivity influence factors based on the model results from this study show that the model is reasonable. In the actual production process, the hydraulic fracture parameter values are not as high as possible, and they have a reasonable range of values. The fracture closure pressure has a significant impact on the production of tight oil reservoirs. The higher the fracture closure pressure is, the greater the fracture conductivity decreases sharply, and the larger the proppant elastic modulus is, the stronger the fracture conductivity. The influence of fracture conductivity on the production in tight oil reservoirs has an obvious point, and when the value is less than the point, the production effect is good. Improved production can be achieved by balancing the relationship between fracture parameters. The findings of this study can help to better understand the influence of fracture parameters on productivity and contribute to increasing well production and improved development of tight oil reservoirs.

D. Nurfiani, X. Wang, H. Gunawan et al.

Abstract Marapi in Sumatra is characterized by frequent short‐lived explosions and small eruptions (Volcanic Explosivity Index 1–2) and in the past 250 years, the volcano has erupted >60 times. Recent volcanic bombs and the presence of broadband seismic stations lead us to reconstruct the plumbing system of the volcano through an interdisciplinary study. A petrologic study of the summit bombs uses pyroxene, plagioclase and glass compositions to obtain pressures and temperatures of magma storage as well as identify pre‐eruptive processes. Two‐pyroxene geothermobarometry provides pre‐eruptive crystallization pressure estimates of 4–7 kbar (∼15–26 km). Compositional and textural analyses of plagioclase and pyroxene crystals indicate that mafic magma recharge was followed by mixing with the resident magma and renewed crystallization prior to eruption. In order to further image the magma reservoir, we performed a joint inversion of teleseismic receiver functions and surface waves (H/V ratio). The inversion reveals a low velocity zone (LVZ) at depths of 15–21 km that has 7 ± 3% shear velocity reduction, corresponding to an estimated melt fraction of 5 ± 2%. The depth of this LVZ overlaps with the depth of magma storage estimated from petrology, constraining it with high confidence. Such a combined interdisciplinary study provides valuable information for evaluating future periods of unrest, laying out a framework for the interpretation of incoming monitoring data and signals to look out for in order to improve eruption forecasts.

Chris Adesola Samakinde, Jan Marinus Van Bever Donker, Ray Durrheim et al.

Abstract The Barremian-Cenozoic depositional sequences in the northern Orange Basin, SW, South Africa, were investigated using the principles of seismic stratigraphy to understand the interplay of tectonics and sedimentary processes in the distribution of potential hydrocarbon reservoirs. A seismic stratigraphic workflow (seismic sequence, seismic facies and lithofacies analysis) was completed by utilising three seismic lines (L1, L2 and L3) tied to Wireline data (gamma, checkshots and sonic) in two exploration wells (A1 and A2). Seven depositional sequences were mapped followed by the creation of lithofacies log interpreted from the gamma-ray log (GR) by setting maximum GR value at 60 API for Sandstone, 60–100 API for Siltstone and above 100 API for Shale. Six seismic facies units are recognised based on internal geometry and configurations of the seismic reflectors; Tangential-Oblique (SF1), Hummocky (SF2), Wavy-Parallel (SF3), Chaotic (SF4), Sub-parallel/parallel (SF5) and Divergent (SF6). SF4 is dominant within the Barremian-Aptian sequence and expressed in an incised valley fill, suggesting mass transport deposition accompanied by strong hydrodynamic conditions. Evidence of sedimentary basins progradation is seen within the Late-Albian-Turonian sequences, because of the occurrences of SF2, SF6 and SF 4 facies. SF5 facies is prominent in the Maastrichtian/Campanian sequence, indicating that the deposition of sediments may have been accompanied by uniform margin subsidence after the Late-Cretaceous uplift of the Africa margin. The occurrence of SF1 and SF4 facies within the Cenozoic sequence indicates terrigenous pro-deltaic deposits and mass transport deposits, respectively. Further results from seismic-lithofacies modelling reveal that sand deposits of Barremian-Aptian (SF4 facies unit) and Albian sequences (SF2 and SF6 facies units) are potential stratigraphic reservoirs in this part of the basin.

Mortadha Alsaba, Abdullah Al Marshad, Ahmed Abbas et al.

Abstract While drilling through shale formations, shale hydration, including shale swelling and dispersion, is frequently reported as the main wellbore instability problems, particularly when conventional drilling fluids (water-based) are used. These problems have many adverse effects on the drilling operations resulting in non-productive time. Nanoparticles have been recently introduced as a unique alternative to improve the performance of water-based drilling fluids for shale applications. This paper presents an experimental evaluation to investigate the effectiveness of an inhibitive nano-water-based drilling fluid in reducing the swelling of Zubair shale formation. Well-preserved core samples, which were retrieved from Zubair formation, were characterized using X-ray diffraction, and X-ray fluoresces to quantify the amount of the swelling minerals. Scanning electron microscopy was used to identify the existence of microfractures within the samples. Three different nano-based drilling fluids containing titanium dioxide (TiO2), copper oxide (CuO), and magnesium oxide (MgO) at two different concentrations (0.5% and 1.5% by vol) were evaluated through a set of tests to assess the shale reactivity in the presence of these nano-based fluids. In addition, the effect of these nanoparticles on the rheological and filtration properties was studied. The results showed that the shale samples contain 41.26% silicon dioxide (SiO2) and 22.73% aluminum oxide (Al2O3), indicating the presence of smectite and illite. Based on the reactivity tests, fluids containing CuO at 1.5% by vol outperformed the other fluids in terms of reducing the reactivity, where the expansion rate was reduced by 82.7% compared to the reference sample submerged in fresh water. In addition, the addition of nanoparticles resulted in reducing the plastic viscosity, increasing both the yield point and gel strength, and reducing the fluid loss under low-pressure low-temperature conditions.

Asad Ali Narejo, Abdul Majeed Shar, Noor Fatima et al.

Abstract We have studied geochemical characteristics, mineralogy and origin of the manganese deposits in Bela ophiolitic complex. Geochemical investigation was conducted in order to discuss the elemental correlations and to infer the probable origin of manganese deposits in Bela ophiolites. Ore microscopy was conducted to identify different manganese minerals and their paragenesis. Psilomelane and braunite were found to be the major ore minerals. Mineral paragenesis sequence as observed was braunite forming first. Psilomelane formed in later stages because it has been found that psilomelane is altering the braunite. Magnetite was observed as a secondary mineral as vein filling and cutting through both the braunite and psilomelane, therefore, younger than the psilomelane and braunite. The gangue minerals observed in the studied samples were quartz, cryptocrystalline silica and calcite. The correlations among different major and trace elements showed diversity of relations. MnO showed negative correlation with Fe2O3 (− 0.73), Si2O (− 0.27), positive correlation with Al2O3 (0.54), TiO2 (0.36), MgO (0.22), Pb (0.23), Ni (0.07), Cr (0.12), and no correlation was established with Zn, Cu, Co. Binary diagram of Si versus Al and ternary discrimination diagrams of Fe–(Ni + Co + Cu) × 10–Mn and Ni–Zn–Co showed hydrothermal-diagenetic-type deposits. Furthermore, the present study suggests that the enriched manganiferous fluid during its upward movement within the Tethys oceanic crust near spreading center started precipitating Mn along with Fe on the sea floor. Later on, these manganese minerals were obducted on land between Indian plate and Helmond block of Eurasian plate in existing position accompanying pillow basalt and pelagic sediments.

Pan-Pan Zhang, Shou-Ceng Tian, Mao Sheng et al.

Abstract Properties of shale in an acid environment are important when acid or CO2 is injected into geologic formations as a working fluid for enhanced oil and gas recovery, hydraulic fracturing and reduced fracture initiation pressure. It has previously been shown that acid fluids can enhance the formation conductivity and decrease the hardness of shale. However, less is known about the effect of dilute acid on the adhesion properties of shale. In the study, shale samples are characterized in detail with advanced analysis. Adhesion properties of shale via dilute acid treatment were revealed by atomic force microscopy (AFM) for the first time. Results indicate that acid treatment can greatly enhance adhesion forces of the shale surface. After acid treatment, the average adhesion forces show a platform-like growth with an increase in loading force. Through analysis of results from AFM, scanning electron microscopy, and X-ray diffraction, we affirm that the enhanced adhesion forces are mainly from increased specific surface area and reduced elastic modulus. The results presented in this work help understand the adhesion properties of shale oil/gas present in an acidic environment, which have great significance in unconventional resources development.

Keizo Ishii

When charged particles collide with atoms, atomic inner shell electrons become ionized, producing characteristic X-rays. This phenomenon is called particle-induced X-ray emission (PIXE). The characteristic X-ray production cross-sections from PIXE are very large, and the characteristic X-rays of elements contained in a sample are easily measured by a Silicon detector with a high energy resolution. Hence, sodium to uranium can be detected with a sensitivity of ppb~ppm, and PIXE has been applied to trace element analysis. Scanning ion beams can be used to obtain the spatial distributions of elements in a sample. Furthermore, the distributions of elements inside a cell can be investigated using micro ion beams. PIXE analysis is a very useful technique for multi-elemental analysis and is now widely used in many fields and applications, including chemistry, medicine, biology, archaeology, agriculture, materials science, fisheries science, geology, petrology, environmental study, contamination monitoring, resource search, semiconductors, metal, astrophysics, earth science, criminal investigations, and food.

Guo Qi, Wang Xihong, Meng Lixin

Abstract The Ming Huazhen group of Gang Dong Oilfield is a medium–high permeability reservoir of meandering stream deposits. It has a high areal and vertical heterogeneity and has entered the stage of extra-high water-cut. Point bar is an important development area for oil sands in meandering stream deposits and the development of a lateral layer is an important factor controlling the distribution of residual oil. The change rule of water displacement in medium–high permeability reservoirs was clearly determined by laboratory experiments. A numerical simulation method was used to determine the time-varying physical properties of the reservoir. Based on the internal configuration of the meandering river point bar, the horizontal well excavation method for residual oil development of point bars during the ultra-high water-cut stage is employed on the basis of the evaluation of flow field intensity. The results show that this method can well reflect the distribution of the flow field in a point bar sand body. The degree of extraction increases by 3.2% if horizontal wells are drilled in the weak flow field rather than in other places.

Yu Chen, Chun-Mao Chen, Brandon A. Yoza et al.

Abstract Novel Mn–Fe–Mg- and Mn–Fe–Ce-loaded alumina (Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3) were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters (PRW-ROC). Highly dispersed 100–300-nm deposits of composite multivalent metal oxides of Mn (Mn2+, Mn3+, and Mn4+), Fe (Fe2+ and Fe3+) and Mg (Mg2+), or Ce (Ce4+) were achieved on Al2O3 supports. The developed Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 exhibited higher catalytic activity during the ozonation of PRW-ROC than Mn–Fe/Al2O3, Mn/Al2O3, Fe/Al2O3, and Al2O3. Chemical oxygen demand removal by Mn–Fe–Mg/Al2O3- or Mn–Fe–Ce/Al2O3-catalyzed ozonation increased by 23.9% and 23.2%, respectively, in comparison with single ozonation. Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 notably promoted ·OH generation and ·OH-mediated oxidation. This study demonstrated the potential use of composite metal oxide-loaded Al2O3 in advanced treatment of bio-recalcitrant wastewaters.

Yanqun Yu, Zongyu Chang, Yaoguang Qi et al.

Abstract The high-efficient development of heavy oil is difficult for offshore oil field. Based on the mature technology of onshore heavy oil thermal recovery, a new rod pumping technology of “heavy oil steam stimulation along with conventional sucker rod pumping system” is proposed. According to the structure space of aimed offshore platform, we designed one new kind of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure. The paper also studies the offshore heavy oil thermal recovery well safety technology, establishes a leakage model of wellhead sealing and a mechanical model of sealed rubber sleeve on downhole nonlinear large deformation. The study shows that a series of equipment for offshore rod pumping oil recovery and the key technology of well safety lay a solid foundation for carrying out rod pumping of offshore heavy oil thermal recovery.

R. Armstrong L. Osborne

There are few cases of open caves that have been reliably dated to ages greater than 65 Ma. This does not mean that such caves are extremely rare, rather it is difficult to reliably establish that a cave, or palaeokarst related to a cave, is this old. Relative dating methods such as: - regional stratigraphic, lithostratigraphic, biostratigraphic, relative climatic, relative isotopic, morphostratigraphic, and regional geomorphic are very useful. They suffer however from significant difficulties, and their results lack the impact of a crisp numerical date. While many of the methods used to date younger caves will not work over the required age range, some isotopic methods and palaeomagnetic methods have been applied with varying degrees of success. While finding something to date and having it dated is difficult enough, producing the date is rarely the end of the story. The difficult issue is not the date or relative correlation itself, but what the date or correlation means. Demonstrating that caves are ancient seems to rapidly become beset with the old adage that “extraordinary claims require extraordinary proof”. The presence of a well-dated or correlated sediment in a cave does not necessarily mean that the cave is that old or older. Perhaps the dated material was stored somewhere in the surrounding environment and deposited much more recently in the cave. A lava flow in a cave must be demonstrated conclusively to be a flow, not a dyke or a pile of weathered boulders washed into the cave. It must be conclusively shown that dated minerals were precipitated in the cave and not transported from elsewhere. There seems little doubt that in the future more ancient caves, or ancient sections of caves, will be identified and that as a result our perception of the age of caves in general will change.   R.A.L. Osborne: Datiranje starih jam in z njimi povezanega paleokrasa   Je le nekaj primerov odprtih jam, ki bi imele zanesljivo določeno starost nad 65 milijonov let. To ne pomeni, da so take jame izredno redke, ampak da je težko zanesljivo ugotoviti, da so oziroma paleokras, povezan z njimi, res tako stare. Relativne metode datiranja, kot so regionalno stratigrafsaka, litostratigrafska, biostratigrafska, relativno klimatološka, relativno izotopska, morfostratigrafska in regionalno geomorfološka, so zelo uporabne. Imajo pa pomembne pomanjkljivosti, saj njihovi izsledki ne temelje na jasnih številčnih podatkih. Medtem, ko marsikatera od metod, ki so uporabne za datiranje mlajših jam, ni uporabna za omenjeno starost, pa je bilo uporabljenih več izotopskih in paleomagnetnih metod z različnim uspehom. Težko je najti snov za datiranje in jo datirati, a sama starost še ni konec zgodbe. Težava ni z datiranjem ali s korelacijo, ampak v tem, kaj starost oziroma korelacija pomenita. Dokazovanje, da so jame stare, je hitro odpravljeno s pregovorom »Izredni izsledki zahtevajo izredne dokaze«. Dobro datirani ali korelirani sedimenti v jami še ne pomenijo, da je jama toliko stara ali starejša. Morda je bilo datirano gradivo odloženo nekje v okolici in šele mnogo kasneje preneseno v jamo. Lavin tok v jami mora biti neizpodbitno določen kot lavin tok, ne pa da je dyke ali balvani, prenešeni v jamo. Neizpodbitno mora biti dokazano, da so bili datirani minerali izločeni v jami in ne preneseni od nekod drugod. Nedvomno bo v bodoče spoznanih več starih jam ali njihovih delov in zaradi tega se bo tudi naše pojmovanje o starosti jam v celoti spremenilo.

W. Engelhardt, H. Füchtbauer, G. Müller et al.