Assessment of geomechanical concept for natural and manmade fractures in bazhenov and tyumenskoe formations using an example of study in Em-Yoga field Krasnoleninsky arch West Siberia

Abstract

This paper is based on study of formations in Bazhenov and Tyumenskoe horizons of Em-Yoga field Krasnoleninsky arch West Siberia with the aim of defining the geomechanical concepts of studied area. Hydrocarbon production from Bazhenov and Tyumenskoe formations in West Siberia is actually established through number of pilot wells with production testing. Economic profitability of producing wells depends on the efficiency of hydraulic fracturing in cases where the technology is predefined by reservoir development project. This article describes the principles and prerequisites of hydraulic fracturing mechanics under geomechanical conditions of the studied rocks. Tyumenskoe and Bazhenov formations are dated to Upper and Middle Jurassic geological time. Geological depositional environment and posterior transformations in time have created specific conditions for rock geomechanics. Rock mechanics in studied formations practically predetermines the concept of how rock is fractured. This work presumes basis for typification and description of fractures occurred naturally and created as a result of hydraulic fracturing and how those interfere with each other. This work is stand on the accumulated results of the ongoing study and actual data from producing wells in Em-Yoga field Krasnoleninsky arch West Siberia. The Jurassic rocks studied in this article are stratigraphically divided into formations of Tyumenskoe, Abalak and Bazhenov horizons. Enacted stratigraphic cross-sectional classification describes the formations of Tyumenskoe horizon as porous rock, Abalak horizon as cavernous-porous naturally fractured and Bazhenov as naturally fractured and micro-porous types of rock.