Lithospheric structure along wide-angle seismic profile GEORIFT 2013 in Pripyat–Dnieper–Donets Basin (Belarus and Ukraine)

The GEORIFT 2013 (GR'13) WARR (wide-angle reflection and refraction) experiment was carried out in 2013 in the territory of Belarus and Ukraine with broad international co-operation. The aim of the work is to study basin architecture and deep structure of the Pripyat-Dnieper-Donets Basin (PDDB), which is the deepest and best studied Palaeozoic rift basin in Europe. The PDDB is located in the southern part of the East European Craton (EEC) and crosses Sarmatia-one of the three segments of the EEC. The PDDB was formed by Late Devonian rifting associated with domal basement uplift and magmatism. The GR'13 extends in NW SE direction along the PDDB strike and crosses the Pripyat Trough (PT) and Dnieper Graben (DG) separated by the Bragin Uplift (BU) of the basement. The field acquisition along the GR'13 (of 670 km total length) involved 14 shots and recorders deployed every similar to 2.2 km for several shot points. The good quality of the data, with first arrivals visible up to 670 km for several shot points, allowed for construction of a velocity model extending to 80 km depth using ray-tracing modelling. The thickness of the sediments (Vp <6.0 km s(-1)) varies from 1-4 km in the PT, to 5 km in the NW part of the DG, to 10-13 km in the SE part of the profile. Below the DG, at similar to 330-530 km distance, we observed an upwarping of the lower crust (with Vp of similar to 7.1 km s(-1)) to 25 km depth that represents a rift pillow or mantle underplate. The Moho shallows southeastwards from similar to 47 km in the PT to 40-38 km in the DG with mantle velocities of 8.35 and similar to 8.25 km s(-1) in the PT and DG, respectively. A near-horizontal mantle discontinuity was found beneath BU (a transition zone from the PT to the DG) at the depth of 50-47 km. It dips to the depth of similar to 60 km at distances of 360-405 km, similar to the intersecting EUROBRIDGE'97 profile. The crust and upper mantle structure on the GR'13 may reflect varying intensity of rifting in the PDDB from a passive stage in the PT to active rifting in the DG. The absence of Moho uplift and relatively thick crystalline crust under the PT is explained by its tectonic position as a closing unit of the PDDB, with a gradual attenuation of rifting from the southeast to the northwest. The most active stage of rifting is evidenced in the DG by a shallower Moho and by a presence of a rift pillow caused by mafic and ultramafic intrusions during the active phase. The junction of the PT and the DG (the BU) locates just at its intersection with the NS regional tectonic zone Odessa-Gomel. Most likely, the 'blocking' effect of this zone did not allow for further propagation of active rifting to the NW.Peer reviewe

Relaxed Cutting Plane Method for Solving Linear Semi-Infinite Programming Problems

One of the major computational tasks of using the traditional cutting plane approach to solve linear semi-infinite programming problems lies in finding a global optimizer of a nonlinear and nonconvex program. This paper generalizes the Gustafson and Kortanek scheme to relax this requirement. In each iteration, the proposed method chooses a point at which the infinite constraints are violated to a degree, rather than a point at which the violations are maximized. A convergence proof of the proposed scheme is provided. Some computational results are included. An explicit algorithm which allows the unnecessary constraints to be dropped in each iteration is also introduced to reduce the size of computed programs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45251/1/10957_2004_Article_411711.pd

Оценка выноса тепла при бурении скважины / В. И. Зуй , Я. Г. Грибик, А. Л. Сусленко

A field experiment to estimate the withdrawal of heat by a circulating mud was described on the basis of the borehole «Novo-Korenevskaya-13» located within the Pripyat Trough (Belarus) which was in a drilling process. A rock fragmentation process is accompanied by a heat release. Drilling of deep wells is fulfilled using a drilling mud (usually a clay mud). It cools the tool which frays and crushes rocks at the well bottom as well as removes detritus from a wellbore to the ground surface. The paper is devoted to calculation of the heat efflux by circulating drilling fluid during this well drilling. It was shown that this mud, circulating along the wellbore, evacuates to the ground surface not only detritus but provides the heat efflux as well. The experiment included the temperature monitoring of the drilling mud pumped into a drill string and its outflow from the well. We discuss the heat power delivered to the ground surface. It was confirmed that the heat efflux by the circulating fluid in a wellbore could attain hundreds of kilowatts or even slightly exceed 1 MWth depending on the drilling depth, drillable rock types and the natural rock temperature at the considered depth. An assessment of heat withdrawal in the process of deep borehole drilling during oil exploration works within the Pripyat Trough represents both a scientific and practical interest. The heat release during the drilling process could be used for practical purposes. = Описан полевой эксперимент по выносу тепла циркулирующим буровым раствором на базе скважины «Ново-Кореневская-13» Припятского прогиба (Беларусь). Доказывается, что буровой раствор, циркулирующий по стволу скважины, не только выносит на земную поверхность обломки разрушенной горной породы, но и обеспечивает вынос тепла. Исследование включало в себя мониторинг температуры бурового раствора: сначала – закачиваемого в бурильную колонну, затем – на вaыходе из скважины. Представлены расчеты выноса тепла циркулирующим буровым раствором в процессе бурения скважины. Оценивается тепловая мощность, доставляемая на земную поверхность. Подтверждено, что она может достигать сотен киловатт или даже незначительно превышать 1 МВт в зависимости от глубины бурения, типа разбуриваемых пород и их естественной температуры на рассматриваемой глубине. Показано, что оценка выноса тепла в процессе бурения глубокой нефтепоисковой скважины в пределах Припятского прогиба представляет как научный, так и практический интерес. Тепло, выделяющееся при бурении скважин, может быть использовано для практических нужд

Оценка выноса тепла при бурении скважины / В. И. Зуй , Я. Г. Грибик, А. Л. Сусленко

A field experiment to estimate the withdrawal of heat by a circulating mud was described on the basis of the borehole «Novo-Korenevskaya-13» located within the Pripyat Trough (Belarus) which was in a drilling process. A rock fragmentation process is accompanied by a heat release. Drilling of deep wells is fulfilled using a drilling mud (usually a clay mud). It cools the tool which frays and crushes rocks at the well bottom as well as removes detritus from a wellbore to the ground surface. The paper is devoted to calculation of the heat efflux by circulating drilling fluid during this well drilling. It was shown that this mud, circulating along the wellbore, evacuates to the ground surface not only detritus but provides the heat efflux as well. The experiment included the temperature monitoring of the drilling mud pumped into a drill string and its outflow from the well. We discuss the heat power delivered to the ground surface. It was confirmed that the heat efflux by the circulating fluid in a wellbore could attain hundreds of kilowatts or even slightly exceed 1 MWth depending on the drilling depth, drillable rock types and the natural rock temperature at the considered depth. An assessment of heat withdrawal in the process of deep borehole drilling during oil exploration works within the Pripyat Trough represents both a scientific and practical interest. The heat release during the drilling process could be used for practical purposes. = Описан полевой эксперимент по выносу тепла циркулирующим буровым раствором на базе скважины «Ново-Кореневская-13» Припятского прогиба (Беларусь). Доказывается, что буровой раствор, циркулирующий по стволу скважины, не только выносит на земную поверхность обломки разрушенной горной породы, но и обеспечивает вынос тепла. Исследование включало в себя мониторинг температуры бурового раствора: сначала – закачиваемого в бурильную колонну, затем – на вaыходе из скважины. Представлены расчеты выноса тепла циркулирующим буровым раствором в процессе бурения скважины. Оценивается тепловая мощность, доставляемая на земную поверхность. Подтверждено, что она может достигать сотен киловатт или даже незначительно превышать 1 МВт в зависимости от глубины бурения, типа разбуриваемых пород и их естественной температуры на рассматриваемой глубине. Показано, что оценка выноса тепла в процессе бурения глубокой нефтепоисковой скважины в пределах Припятского прогиба представляет как научный, так и практический интерес. Тепло, выделяющееся при бурении скважин, может быть использовано для практических нужд