Based on fossil organism remains including plant macrofossils, charcoal, pollen, and invertebrates preserved in syngenetic deposits of the Batagay permafrost sequence in the Siberian Yana Highlands, we reconstructed the environmental history during marine isotope stages (MIS) 6 to 2. Two fossil assemblages, exceptionally rich in plant remains, allowed for a detailed description of the palaeovegetation during two climate extremes of the Late Pleistocene, the onset of the last glacial maximum (LGM) and the last interglacial. In addition, altogether 41 assemblages were used to outline the vegetation history since the penultimate cold stage of MIS 6. Accordingly, meadow steppes analogueto modern communities of the phytosociological order Festucetalia lenensis formed the primary vegetation during the Saalian and Weichselian cold stages. Cold-resistant tundra-steppe communities (Caricirupestris-Kobresietea bellardii) as they occur above the treeline today were, in contrast to more northernlocations, mostly lacking. During the last interglacial, open coniferous woodland similar to modernlarch taiga was the primary vegetation at the site. Abundant charcoal indicates wildfire events duringthe last interglacial. Zoogenic disturbances of the local vegetation were indicated by the presence ofruderal plants, especially by abundant Urtica dioica, suggesting that the area was an interglacial refugium for large herbivores. Meadow steppes, which formed the primary vegetation during cold stagesand provided potentially suitable pastures for herbivores, were a significant constituent of the plantcover in the Yana Highlands also under the full warm stage conditions of the last interglacial. Consequently, meadow steppes occurred in the Yana Highlands during the entire investigated timespan from MIS 6 to MIS 2 documenting a remarkable environmental stability. Thus, the proportion of meadowsteppe vegetation merely shifted in response to the respectively prevailing climatic conditions. Their persistence indicates low precipitation and a relatively warm growing season throughout and beyond the late Pleistocene. The studied fossil record also proves that modern steppe occurrences in the Yana Highlands did not establish as late as in the Holocene but instead are relicts of a formerly continuoussteppe belt extending from Central Siberia to Northeast Yakutia during the Pleistocene. The persistence of plants and invertebrates characteristic of meadow steppe vegetation in interior Yakutia through out the late Quaternary indicates climatic continuity and documents the suitability of this region as arefugium also for other organisms of the Pleistocene mammoth steppe including the iconic large herbivores

На основе остатков ископаемых организмов, включая макрофоссилии растений, древесный уголь, пыльцу и беспозвоночных, сохранившихся в сингенетических отложениях Батагайской мерзлотной толщи Сибирско-Янского нагорья, мы реконструировали историю окружающей среды в течение морских изотопных стадий (MIS) 6-2. Две ископаемые коллекции, исключительно богатые растительными остатками, позволили детально описать палеорастительность во время двух климатических экстремумов позднего плейстоцена - наступления последнего ледникового максимума (LGM) и последнего межледниковья. Кроме того, всего 41 коллекция была использована для описания истории растительности с предпоследнего холодного этапа MIS 6. Соответственно, луговые степи, аналогичные современным сообществам фитосоциологического порядка Festucetalia lenensis, формировали основную растительность во время саальского и вейхзельского холодных этапов. Холодостойкие тундрово-степные сообщества (Caricirupestris-Kobresietea bellardii) в том виде, в котором они встречаются сегодня выше линии леса, в отличие от более северных районов, в основном отсутствовали. Во время последнего межледниковья основной растительностью на участке были открытые хвойные леса, похожие на современную лиственничную тайгу. Обилие древесного угля указывает на лесные пожары во время последнего межледниковья. Следовательно, луговые степи существовали на Янской возвышенности на протяжении всего исследуемого периода от МИС 6 до МИС 2, что свидетельствует об удивительной экологической стабильности. Таким образом, доля луговой степной растительности просто менялась в зависимости от преобладающих климатических условий. Их сохранение свидетельствует о низком количестве осадков и относительно теплом вегетационном периоде на протяжении всего позднего плейстоцена и после него. Изученная ископаемая летопись также доказывает, что современные степи на Янской возвышенности возникли не позднее голоцена, а являются реликтами ранее непрерывного степного пояса, простиравшегося в плейстоцене от Центральной Сибири до Северо-Восточной Якутии. Сохранение растений и беспозвоночных, характерных для растительности луговых степей во внутренней Якутии на протяжении позднего четвертичного периода, указывает на климатическую непрерывность и подтверждает пригодность этого региона в качестве арефугиума и для других организмов плейстоценовой мамонтовой степи, включая знаковых крупных травоядных

The paper considers compatibility of formation water of the Irelyakh gas and oil field of the Republic of Sakha (Yakutia) with the highly mineralized solution used as an agent of reservoir pressure maintenance (RPM) with an allowance for factors, which influence solubility of salts, salt effect in particular. Also, possibility of concurrent reactions and specific conditions characteristic of the fields of the southwest Yakutia (by the example of the Irelyakh GOF) have been taken into account. It is shown that with the increase of the time length of wells’ flooding with the liquid for RPM the pore space structure undergoes changes due to its calcination and sulphatization, which causes deterioration of reservoir properties and subsequently can complicate the operation of producing wells and the field in the whole.

The group composition of asphaltene-resin-paraffin deposits (ARPD) in the Irelyakh field and their solubility in the composite solvents on the hexane base with the additives consisting of nonionic surface-active substances (NSAS) and concentrates of aromatic hydrocarbons is determined. The results of the investigations show that the additives Neonol AF-9-10 and liquid products of pyrolysis (LPP) are most efficient. The use of these additives allows to increase the efficiency of ARPD breaking and dissolving by 1,3 – 1,6 times as compared with a base solvent. It is shown that the increase in the concentration of individual additives from 0,5 to 3 % causes a decrease in the efficiency of detergent compounds.

Rheological, structural and oil displacing properties of the solutions of polyacrylamide (PAA) and carboxymethylcellulose (CMC) are fully investigated in the conditions of abnormally low reservoir temperatures. Physico-chemical processes occurring at a contact of highly mineralized formation water with the polymer solutions of PAA and CMC, which are different in composition, in the pore space of the reservoir are studied. The possibility of increasing the efficiency of hydrodynamic influence on the reservoir in the conditions of the fields of the southwest Yakutia due to the use of displacing compounds on the water-soluble polymer base is established experimentally.

In the given work perspectives of combined modification of polytetrafluorethylene (PTFE) by fluoroplastic F-4MB in a combination with nanospinel magnesium for the purpose of reception of new cold-resistant polymeric composite materials the tribotechnical appointments with improved deformation-strength characteristics for the oil and gas equipment is shown.

We have studied the process of artificial methane hydrates obtaining in static conditions from distilled and "secondary" water (prepared by the decomposition of methane hydrate), as well as the additional metal surface using inside of cameras. It was found dependence from the type of the liquid phase and the presence/absence of additional metal surface inside the camera; in the same initial conditions of temperature and pressure, it can be obtained samples with different degrees of transformation of the "water-gas" to hydrate and various crystalline morphology.

Лошадь саха: этнический символ в пост-коммунистической Республике Саха (Якутия)

Предварительные заметки по пастбищному делу и мастерству в оленеводстве Восточной Сибири: изучение Южной Якутии

Новые технологии как фактор сохранения экологического баланса в Арктике

Об экологической безопасности Северо-Востока России