Geostatistics assisted by machine learning for reservoir property modeling: A case study in presalt carbonates of Buzios Field, Brazil

An embedded model estimator (EMBER) petrophysical modeling algorithm has been applied to obtain effective porosity and permeability within the presalt carbonate reservoirs of the Barra Velha Formation in Buzios Field, Santos Basin. This advanced methodology was used due to the heterogeneity and complexity of the reservoirs, which makes modeling by conventional geostatistical methodologies difficult. For effective porosity modeling, we chose one facies model, one stratigraphic seismic attribute (acoustic impedance), and one structural seismic attribute (local flatness) as secondary variables. Permeability was modeled by using the best effective porosity simulation result as a secondary variable. Our results demonstrate that average effective porosity and permeability were 0.10 v/v and 440 md, respectively, indicating good reservoir quality throughout the studied area. A vertical trend of high effective porosities and permeabilities for the basal and uppermost reservoir sections was identified in our results, as well as a trend with lower values for these reservoir properties for the intermediate reservoir section. The lower section of the formation presented more continuity, and we infer it to be the best reservoir interval. We observed two horizontal trends for these reservoir properties at the formation top: one of higher values aligned to the north–south direction at the structural highs and another of lower reservoir properties related to isolated structural lows within structural highs. Correlation between modeled results and the blind test ANP-1 well upscaled properties was high, and upscaled well-log property distributions were preserved in the EMBER simulations, proving the predictive capacity of the algorithm. Finally, conditional distributions analysis indicated that the basal section of the Barra Velha Formation presents higher uncertainty for the estimation of effective porosity. Even though this interval is considered to have the best reservoir characteristics, decision making should be done with caution for this section.

The Neoarchean Conglomerate-Hosted Gold of the West Pilbara Craton, Western Australia

Recently discovered Au in boulder conglomerate between the Mesoarchean West Pilbara superterrane basement and the overlying volcano-sedimentary stratigraphy of the Neoarchean Fortescue Group in Western Australia has renewed comparisons with the Witwatersrand conglomerate Au deposits in South Africa. As such, this has reignited the question of the Pilbara and Kaapvaal cratons being linked as part of the postulated Vaalbara continent during the Archean. However, little is known about the origin of the Pilbara conglomerate Au and its host conglomerates, as they are hitherto unstudied, and their formation and/or source is uncertain. Here we present a detailed study on the textures, composition, and sedimentology of one newly discovered Pilbara conglomerate Au deposit at the base of the Neoarchean Fortescue Group in the northwestern Pilbara craton. The Pilbara conglomerate Au occurrences are characteristically Ag-bearing but Hg-poor polycrystalline discoid masses that are overgrown by Au-poor chloritic halos, which are further enveloped by a hydrothermal alteration halo of disseminated Au within chlorite. Both the discoids and the auriferous chlorite halo are Ag bearing, with up to ~9 wt % Ag, consistent with a hydrothermal (orogenic) origin. The discoids do not display any physical or chemical evidence for sedimentary transport; thus, their formation (placer versus hydrothermal) remains unclear. However, the position of the Au in the conglomerate, limited to the basal section of the conglomerate, is difficult to account for in a purely hydrothermal deposit model. We argue the Pilbara conglomerate Au represents a modified placer deposit from a primary orogenic Au source, with surface evidence for sedimentation removed by partial dissolution during later hydrothermal alteration in the host conglomerate and the crystalline basement. While the basal Fortescue Group conglomerate Au shares commonalities with the time equivalent (>~2.7 Ga) Venterspost Conglomerate Formation, which overlies the Witwatersrand Supergroup, inconsistencies remain, with different Au chemistries and tectonic, magmatic, sedimentary, and metamorphic-metallogenic histories of the Pilbara and Kaapvaal cratons prior to deposition of the >2.7 Ga conglomerate sequences. This collectively indicates the drivers of Au metallogenesis and ultimate Au deposition in conglomerate facies were fundamentally different in the Pilbara and Kaapvaal cratons.

Paramathes evdomo, a new species from Sichuan, southwestern China (Lepidoptera, Noctuidae, Noctuinae)

Paramathes Boursin, 1954 is a Noctuinae genus closely related to Xestia Hübner and distributed in high mountain regions of West and Central China. Paramathes and the Xestia—complex (the Palaearctic and Oriental species have never been revised) show a lot of synapomorhies, which indicate the close relationship, particularly in the male genitalia: lanceolate or spatulate uncus, the presence of apical process and pseudopollex on the valvae, carinal thorn or bulb. However, these characters are not present all in most of the Xestia; e. g. most of them have long, narrow uncus, no apical process on the valvae, absent carinal thorn or bulb; or are without being combined these. In the females, the differences are more conspicuous; the postero - bilateral lobes of the strongly sclerotized antrum are very large in Paramathes (these are not present in most of the Xestia, or much smaller), the corpus bursae short and ample, the appendix bursae prominent. The autapomorhies of the Paramathes are the Eugnorisma—like forewing pattern, the slightly dentate, ribbon shaped sclerotization extending from the carina onto the basal section of the vesica in the males, while those are in the females the very large postero - bilateral lobes of the strongly sclerotized antrum and the presence of the four signa in the corpus bursae. A revision of Paramathes was recently published by Varga et al. (2015), who included in the genus five species, such as P. tibetica Boursin, 1954, P. perigrapha (Püngeler, 1900), P. amphigrapha Boursin, 1954, P. pulchrisigna Boursin, 1954, P. xestioides Varga, Ronkay, Ronkay, Gyulai, 2015 and one subspecies P. perigrapha simonyisandori Varga, Ronkay, Ronkay, Gyulai, 2015. Paramathes daochengi was described a year later by Saldaitis & Gyulai (2016). During a lepidopterological expedition to the northwestern part of China’s Sichuan Province in June of 2019, a short series of Paramathes specimens (Figs 1, 2) similar to Paramathes daochengi Saldaitis & Gyulai, 2016 (Fig. 3) was collected. However, after examining their genitalia by second author, it was concluded by the authors, that they belong to an undescribed species which is described below.

Influence of a thermal treatment on the tensile strength and equilibrium moisture content of bamboo (Guadua angustifolia Kunth)

Thermal treatments applied to lignocellulosic materials were found to induce internal chemical reactions, which modified the physical and mechanical properties and dimensional stability of the material. A 3-year-old basal section of bamboo (Guadua angustifolia Kunth), with no nodes and no skin, was subjected to a thermal treatment at temperatures which ranged from 160 to 200 °C for 1 to 4 h. The tensile stiffness showed a slight increase with temperature and time, while the tensile strength showed a notable increase at 160 °C for 2 h. There was a 5% difference in the equilibrium moisture content at 80% relative humidity between the untreated samples and the 200 °C, 4 h treatment.

Evaluation of the Hydrocarbon Potentials of Shale Exposures at Okpekpe in Edo North

This study evaluates the source rock characteristics of rock exposures along a newly exposed road cut in Okpekpe. An integrated technique of organic geochemical analysis and biostratigraphy evaluation were adopted to determine the source rock quality, Maturation index, kerogen types, depositional environment andsediment age. Results of organic geochemistry gave total organic carbon (TOC) value between 0.81 to 3.04 w.t% (2.08wt.% average) indicative of a good source potentials. The plot of Total Sulphur Content (TSC) against TOC suggests a transitional depositional environment for the samples while the plot of hydrogen index (HI) against oxygen index (OI) shows that the samples are capable of generating mixed type II/III kerogen. Palynological analysis revealed that the basal section of the exposure is characterized by the occurrences of typical and moderately rich Late Cretaceous – Early Tertiary palynomorphs. While the upper section is poorly rich in palynomorph abundance but with spot occurrences. The palynomophs asssemlages is of Late Maastrichtian - Early Paleocene and the outcrop is characterized by the presence of terrestrial pollens and spores indicating a continental to transitional depositional environment, typical of the Mamu Formation of the Anambra Basin.

Sodium Nitroprusside Stimulates Micropropagation and TDZ Induces Adventitious Shoots Regeneration in Red Flesh Apple Malus niedzwetzkyana Koehne Dieck ex

The aim of the present investigation was to optimize protocols for micropropagation and adventitious shoot regeneration from leaf explants of two wild ecotypes of red flesh apple Malus niedzwetzkyana for future breeding programs. At the proliferation stage, different concentrations of sodium nitroprusside (SNP) and triacontanol (TRIA) were compared. To optimize shoot regeneration from leaf explants, interactive effects of 1-phenyl-3-(1,2,3-thidiazol-5-yl)-urea – thidiazuron (TDZ), indole-3-butyric acid (IBA) and two explant types were investigated. At rooting stage, the effect of exposure time of microshoots to darkness and exposure time to different concentrations of IBA and α-naphthalene acetic acid (NAA) were compared. The results showed that SNP affected the growth rate significantly and the maximum multiplication rates per explant (9.6 in the first ecotype and 8.8 in the second) were produced in the Quoirin and Lepoivre medium containing 17 SNP µM, in addition to 4 µm 6-benzylaminopurine (BAP) and 3 µm gibberellic acid (GA3). IBA and TDZ affected the adventitious shoot regeneration from leaf explants significantly, the highest number of regenerated shoots (18.3 per explant) was obtained from the basal section of the leaves cultured on the medium containing 2 μM IBA and 15 μM TDZ. At rooting stage, the maximum rooting (88.6%) was obtained in the result of one weak exposure to darkness on medium containing 3 μM IBA.

PREFERENSI PERTUMBUHAN BIBIT GEMBILI [Dioscorea esculenta (Lour.) Burkill] ASAL BAHAN TANAM DAN TEKNIK PENANAMAN BERBEDA

Lesser yam (Dioscorea esculenta (Lour.) Burkill) tubers have two important roles in conventional cultivation, as the food as well as the propagation material. The stem cuttings technique is reported can not produce tubers, while micropropagation is less efficient due to the need of large capital, experts, and specific tools. The other hand, farmers are less interested in cultivating this commodity. It has been reported that mini tuber sett can be used for propagation, but it has not been able to explain the growth preferences in each part of the tuber and its effect on yield. The research aims to provide information about the growth preference of lesser yam seedlings from different planting materials and planting techniques and their effects on yields. The research was carried out in Research Center for Biology, LIPI, Cibinong. The experiment was arranged based on split plots with tubers (apical and basal parts) as the main plot and planting position (vertical and horizontal) as subplots. Each treatment was replicated 3 times, with 5 samples for each replication. The results revealed that the apical part produced better shoots and roots than the basal section. The apical dominance of the lesser yam tuber was very high. It is herefore buds that form in the apical tended to grow faster. This section also produced tuber with a better character. With this information, farmers recommended to use planting materials from the apical part of the tuber with horizontal planting position.

Palpos labiales de Prestonia clarki (Lepidoptera, Pieridae): ultraestructura de órganos sensoriales y sensilas

Research on labial palps of Lepidoptera is scarce and requires the use of Scanning Electron Microscopy techniques. We describe and illustrate the three segments composing the labial palps of the Coliadinae butterfly Prestonia clarki, as well as the distribution of sensilla and both of palp's distinctive structures: the Reuter's sensitive patch and the Palp pit organ; in the palps, the basal segment is the longest, and the distal segment is the shortest. We found chaetic sensilla type 1 on the lateral outer surface of the segments. In the Reuter's sensitive patch and the Palp pit organ, sensilla are specialized. In a lateral internal view of the proximal section of the basal segment, Reuter's sensitive patch looks as an elongated area with hundreds of microtrichia, differentiated into three sections; the adjacent area shows fewer microtrichia of shorter length. In a longitudinal view of the distal segment, at the apex of the segment, is the bottle-shaped Palp pit organ; inside the Palp pit are coeloconic sensilla in the basal section and microtrichia in the distal one. In addition, two indeterminate types of sensilla similar to chaetic ones were found within the Palp pit; which we called chaetic sensilla types 2 and 3; chaetic sensilla type 1 are located on the edge of the Palp pit. The sensilla types and their distribution in the Palp pit agree with those described in other species of Lepidoptera.

First record of the Valanginian positive carbon isotope anomaly in the Mendoza shelf, Neuquén Basin, Argentina: palaeoclimatic implications

The Tithonian-Valanginian time interval in the Mendoza Shelf (Neuquén Basin, Argentina) is well exposed in the Río Salado, Puesto Loncoche and Cuesta del Chihuido sedimentary sections. From those localities, more than fifty preserved oyster shells of the genus Aetostreon sp. were selected and sampled in order to perform the first δ13C curves for this particular time interval. Mineralogical and cathodoluminiscence properties, inner micromorphology of the valves, added to major and trace element geochemistry were analyzed in order to highlight the best C-O isotopic preservation. The δ13C isotope curves show values varying between 0 and -3‰ VPDB for the Tithonian-Berriasian basal section, and a positive excursion of ~2.4-2.7‰ VPDB in the Valanginian upper section. This δ13C up section trend is here considered in order to reveal eminent correlations with other sections from the Neuquén Basin, as well as the Weissert Event from the Tethys area, also on the basis of their ammonite faunal zones. The palaeotemperatures obtained from δ18O preserved values, added to a detailed sedimentological study suggest that observed δ13C anomaly may responds to a global climatic change from warm and dry to warm and humid conditions.

Micropalaeontological dating of the basal Cretaceous section of DSDP Site 249, Leg 25, Mozambique Ridge: implications for the timing of the southern Atlantic–Indian Ocean connection

Tectonic models suggest the absence of a deep water connection on the Mozambique Ridge during early Neocomian time. These models imply the initiation of a deep water connection between the southern Atlantic and Indian oceans formed during Barremian–earliest Aptian times. However, previous biostratigraphic studies of the earliest deep water sediments on the Mozambique Ridge suggest that the basal section is Neocomian in age. Here, we present a new biostratigraphic analysis undertaken to test this tectonic model and determine the earliest age of deep water sedimentation on the Mozambique Ridge. Core samples from the Cretaceous interval 222.05–406.32 m (Cores 19–32) of DSDP Site 249, Leg 25, were sampled for calcareous nannoplankton and palynological analysis. Most of the sampling was concentrated on the Lower Cretaceous interval below 294 m. Our results indicate that the lower sedimentary section is no older than Barremian and therefore provides support for the age proposed by the tectonic models.