ANALYSIS OF FRACTION CONTENTS IN ROCK SCRATCH TESTS FOR ESTIMATING THE ANGLE OF INTERNAL FRICTION FOR THE SEDIMENTARY COVER OF THE KOVYKTA FIELD

The article describes the possibility of using the granulometric analysis of rock cuttings formed in controlled core scratching tests to estimate the angle of internal friction.The study object is the Kovykta gas-condensate field (GCF) that occupies a wide area in the southeastern part of the Irkutsk amphitheater of the Siberian platform. This uniquely complex geological structure holds significant reserves of hydrocarbons. Its sedimentary cover is composed of the Vendian – lower Paleozoic and partly Riphean formations. Their total thickness exceeds 6000 m, as estimated from the new seismic survey data [Vakhromeev et al., 2019].The sedimentary cover of the Kovykta GCF has been studied by surface and borehole geophysical techniques, remote sensing and geostructural methods, in combination with the tectonophysical approach [Seminsky et al., 2018] based on drilling data, including standard and special core sampling data

Etching or Stabilization of GaAs(001) under Alkali and Halogen Adsorption

Experimentally and by ab initio calculations it is shown that adsorption of electropositive cesium on the As-rich surface of GaAs(001) and, in a symmetric fashion, adsorption of electronegative iodine on the Ga-rich surface, induce a decrease of the surface stability, thus facilitating surface etching. Conversely, Cs adsorption on the Ga-rich surface and I adsorption on the As-rich surface lead to an increased surface stability. Etching occurs when adsorption-induced charge transfer weakens the backbonds of the top arsenic atoms for the case of Cs on the As-rich β2(2 × 4) surface and the lateral bonds in the topmost surface layer for I on the Ga-rich ζ(4 × 2) surface. The possibilities of reversible transitions between the two reconstructed surfaces and of atomic layer etching with monolayer precision are demonstrated

ФРАКЦИОННЫЙ АНАЛИЗ СКРЕТЧ-ШЛАМА ДЛЯ ОПРЕДЕЛЕНИЯ УГЛА ВНУТРЕННЕГО ТРЕНИЯ ГОРНЫХ ПОРОД ОСАДОЧНОГО ЧЕХЛА КОВЫКТИНСКОГО МЕСТОРОЖДЕНИЯ

The article describes the possibility of using the granulometric analysis of rock cuttings formed in controlled core scratching tests to estimate the angle of internal friction.The study object is the Kovykta gas-condensate field (GCF) that occupies a wide area in the southeastern part of the Irkutsk amphitheater of the Siberian platform. This uniquely complex geological structure holds significant reserves of hydrocarbons. Its sedimentary cover is composed of the Vendian – lower Paleozoic and partly Riphean formations. Their total thickness exceeds 6000 m, as estimated from the new seismic survey data [Vakhromeev et al., 2019].The sedimentary cover of the Kovykta GCF has been studied by surface and borehole geophysical techniques, remote sensing and geostructural methods, in combination with the tectonophysical approach [Seminsky et al., 2018] based on drilling data, including standard and special core sampling data.В работе показана возможность использования гранулометрического анализа шлама, образующегося при контролируемом царапании горных пород, для прогноза угла внутреннего трения.Объект исследования – Ковыктинское газоконденсатное месторождение (ГКМ), которое занимает значительную территорию, охватывающую юго-восточную часть Иркутского амфитеатра Сибирской платформы, и по особенностям геологического строения и значительному объему углеводородов является уникальным. Осадочный чехол рассматриваемого объекта сложен венд-нижнепалеозойскими и частично рифейскими образованиями, суммарная толщина которых более 6000 м по новым данным сейсморазведки [Vakhromeev et al., 2019].Методы исследования осадочного чехла Ковыктинского ГКМ базируются на наземных и скважинных геофизических исследованиях, дистанционных и геолого-структурных способах в сочетании с тектонофизическим подходом [Seminsky et al., 2018], основу которого составляют данные бурения, в том числе стандартные и специальные исследования кернового материала