The problems of zeolites detection and their influence on development of the productive reservoirs in the Messoyakha group of fields

Abstract

It is found out that zeolites are formed in alkaline environment at diagenesis or katagenesis and reduce permeability and porosity of reservoir rocks. It is shown that zeolite content in reservoir rocks is directly related to the porosity value and can reach 13 % of the total volume of rock. It is quite difficult to detect zones of zeolitization by means of well logs. Therefore logs should be corrected for the possible content of zeolities on the base of core analysis data which provide detection of the intervals with zeolitization. The authors have determined that the process of zeolitization in Messoyakha group of fields is related to the specific stratigraphic intervals and namely with Suhodudinskaya Formation of Lower Cretaceous age. On a regional scale the zeolitized rocks occur in regional fault zones and zones with enclosing rocks undergone strong metasomatic changes. Based on the core and log data the existing depositional environment concept of producing reservoirs of Messoyakha group of fields has been revised and the most favorable conditions and periods of zeolites formation have been determined. In addition, based on the experience of development of fields with high zeolites content, the best method of near wellbore treatment, which has a direct impact on oil recovery enhance, was offered