Forecast estimation of sandstone collectors transformation of Lower-Karmalinsky bituminous deposit during its development by the SAGD method

Abstract

© Published under licence by IOP Publishing Ltd. In order to increase hydrocarbon reserves in recent years, begun to actively involve natural bitumens in the development. On the territory of Tatarstan, one of the experimental sites for testing various technologies for the extraction of bitumen is the Lower-Karmalinsky bitumen deposit. Currently, on the field is testing the SAFD method. According to this technology for the extraction of hydrocarbons, steam is pumped in large volumes at a temperature of about + 180°C. Superheated steam reduces the viscosity of hydrocarbons, making them mobile. However, focusing on the reduction of bitumen viscosity, the problem of mineral phase's transformation due to anthropogenic impact in reservoir is not taken into account. In this work, using thermodynamic modeling, it was shown that the injection of superheated steam into the formation of bitumen-saturated sandstone will lead to the dissolution of calcite cement. Moreover, depending on the salinity of the injected water in the form of steam, the dissolution of carbonates will occur at different temperatures. To improve the technological characteristics and to increase the recoverability of bitumen from reservoir, it is recommended to pump hot water with as little mineralization as possible into sandstone layers. Temperature intervals were established, which should be followed in the process of technological development of bitumen collectors at the stage of heating the reservoir and at the stage of extracting water-bitumen solutions.