«OIL AND GAS GEOLOGY» № 1/2015

CONTENTS

 

OIL AND GAS POTENTIAL PROSPECTS AND EXPLORATION RESULTS

 

Krylov N.A., Zabolotnaya Yu.I., Grizik A.Ya. Estimation of the direction of further hydrocarbon
deposits exploration in Usturt region of Uzbekistan (play analysis)

 

Prospects of further hydrocarbon prospecting were assessed for separate plays (geological exploration directions) of Usturt region of Uzbekistan. On the basement of play analysis tasks for the investigation of the following objects were defined: the Jurassic deposits on the anticlines of the Shakhpakhtin step and Assakeaudan depression, non-anticline traps in the Jurassic deposits of the Eastern Usturt, the benches of the Paleozoic rocks under the local uplifts of platform mantel and the traps inside the Paleozoic sedimentary complex.

 

Sobornov K.O. Structure and oil and gas bearing capacity of the North Uralian foreland: new
data and new opportunities

 

Reinterpretation of legacy geological and geophysical data combined with new regional seismic dataset permitted a considerable review of the traditional views on structure and petroleum
habitat of the structure and petroleum habitat of the North Uralian foreland. New elements of the proposed interpretation include the following: considerable detalisation of the structural geometry of the thrust belt front; identification of deep-seated listric faults on seismic data; better under-standing of the structural features controlling the localization of the Upper Pechora carbonate platform; refined definition of the structural role of the strike-slip faults in regional tectonic setting. Diverse untested hydrocarbon plays are identified due to the reviewed structural framework. They are linked to the blind duplexes and subthrust inversion structures in the fold belt. The Upper Devonian reefs, overlying drapes and zones of karstification subcropping the Frasnian uncon-formity are regarded as primary exploration objectives in the buried Upper Pechora bank.

 

METHODS OF OIL AND GAS DEPOSITS PROSPECTING

 

Bagrintseva K.I., Krasilnikova N.B., Sautkin R.S. Formation conditions and properties of
the Riphean carbonaceous reservoirs of the Yurubcheno-Tokhomsk deposit

 

The article is devoted to the study of reservoir properties of the Riphean low-capacity carbona-ceous sediments of the Yurubcheno-Tokhomskoye field. The authors defined several types of fracturing, presented reservoir properties and described postsedimentation processes that aredeterminant for the formation of the oldest ancient reservoirs in the world.

 

Trofimov D.M., Sim L.A., Shuvaeva M.K. Structural-tectonophysical method of distant research
in exploration and development of oil and gas deposits

 

Principle advantage of structural-tectonophysical method over the traditional complex of oil and gas exploration work is that this method is based on the data of the latest distant survey with high spatial and spectral resolution and continuous field of measured data. This survey provides detailed structural-geodynamic data of different scales. Complex interpretation with discrete system of geological-geophysical data makes it possible to get more detailed information about the structure and the stress-strained state of reservoirs.

 

Entsov I.I. The application of paleotectonic analysis in the areas of development in the Timan-
Pechora province

 

The method of thicknesses used in a paleotectonic analysis, in zones of reef development pos-sesses essential defects. It occurs overcompensation on the sites of reef formation because of more accelerated accumulation of precipitation. Therefore, paleotectonic cuts turn out insuffici-ently informative. A few modified variant of paleotectonic cut construction is offered. In considered areas reefs are laid by clay-marlaceous breeds: roof can be presented as a smoothing sur-face, and as a smoothing line on profiles. From the smoothing line the line downward is the line of clay breeds thickness, upward – carbonate ones. In case of the presence of an around reef zone it’s suggested to draw the line of credible depth of water, and to lay off from it thicknesses of carbo-nate, and then clay breeds.

GEOPHYSICAL INVESTIGATIONS

 

Gutman I.S., Kachkina E.A., Arefjev S.V. Geological structure of the lower cretaceous and the upper jurassic Severo-Pokachevsky field

On the basis of analysis of the system of pale profiles, lined to the soles of strong clay sections in the correlation of the Upper Jurassic and the Lower Cretaceous wells of Severo Pokachevsky field, it is shown that anomalous cuts of Bazhenov suite and Achimov strata formed on under the conditions of alternate keyboard sinking of adjacent tectonic blocks separated by synsedimentary faults.

Votyakov R.V. New data about oil and gas promising areas of the north-eastern part of Predpatomsky trough

 

The article discusses the possibilities and the results of the application of complex spectral-velocity prediction technology (SVP) for the prediction of areas with improved reservoir properties between wells and how to use these areas to forecast hydrocarbon resources.

ECOLOGY AND PROBLEMS OF OIL AND GAS DEPOSITS DEVELOPMENT

 

Taskinbaev K.M. Possible consequences of the exploitation of subsoil resources in the North
Caspian and alternate solutions to ecelogical problems in extraordinary situations

 

The paper presents the analysis of the impact that accident at the well 37, happened in 1986 in Tengiz deposit development, had on the adjacent settlements population. Possible consequences
of the accidents in subsoil resources exploitation in the North, Middle and South Caspian are estimated, and measures reducing detrimental effect of such situations are suggested.

 

ДИСКУССИИ / DISCUSSIONS

 

Kiryukhin A.V., Kireeva T.A. Oil reservoir formation with steam condensate hydrothermal
system conditions according to the results of numerical modeling (at the example of the White
Tiger deposit, Vietnam)

 

Hydrogeologic data of the White Tiger oil deposit confined to granite massif indicates hydro-thermal origin of the oil deposit as the result of condensation of oil-bearing low-mineralized
hydrocarbonate sulphatic fluid. Numerical modeling showed that stable collecting of oil phase in the upper part of steam-condensate hydrothermal reservoir is possible at the expanse of the transportation of oil component in gaseous phase into the upper part of the section with following removal of water component by downward flow of water phase. The model is 1 km x 1 km2 in size with petrophysical and reservoir parameters similar to the granite massif of the White Tiger deposit and with initial equiponderant distribution of oil component in three phases as the result of steam condensate reworking in the upper part of the section in temperature range 240-285 îÑ
and pressure range 63-69 bar. The lens with the oil phase thickness 80 m (So = 0,6) and mass 2,00 million tons is formed on the model. After the following cooling to 90-115 îÑ and natural
flooding of the lower part of the section, mass of the oil phase increases to 3,49 million tons as oil in gaseous phase condensates.