Abstract
Carbonate reservoirs, especially dolomite reservoirs, contain large reserves of oil and gas. The complex diagenesis is quite challenging to document the dolomite reservoirs formation and evolution mechanism. Porosity development and evolution in dolomite reservoirs primarily reflect the comprehensive effect of mineral dissolution/precipitation during dolomitization. In this study, multicomponent multiphase flow and solute transport simulation was employed to investigate dolomitization in the deep carbonate strata of the Tarim Basin, Northwest China, where active exploration is currently under way. One- and two-dimensional numerical models with various temperatures, fluid compositions and hydrodynamic characteristics were established to quantificationally study dolomitization and its effect on porosity. After determining the main control factors, detailed petrologic characteristics in the studied area were also analyzed to establish four corresponding diagenetic numerical models under different sedimentary environments. These models enabled a systematic analysis of mineral dissolution/precipitation and a quantitative recovery of porosity evolution during various sedimentation-diagenesis processes. The results allowed for a quantitative evaluation and prediction of reservoir porosity, which would provide a basis for further oil and gas exploration in deep carbonate reservoirs.
Highlights
Carbonate reservoirs are widely distributed over the world and crucial for oil and gas exploration because of their proven reserves
The formation and evolution of reservoir porosity are the topic of carbonate reservoir research and constitute the premise for the efficiency improvement of oil and gas exploration [5,8,9,10]
The porosity change extent was consistent under various flow rate conditions, but different amounts of time were needed for the porosity to reach the same level
Summary
Carbonate reservoirs are widely distributed over the world and crucial for oil and gas exploration because of their proven reserves. The formation and evolution of reservoir porosity are the topic of carbonate reservoir research and constitute the premise for the efficiency improvement of oil and gas exploration [5,8,9,10]. Reservoir porosity evolution is mainly the result of carbonate minerals dissolution and precipitation, such as dolomitization [11,12,13,14]. Fluid–rock reactions are usually the main factor for the porosity evolution because it results in carbonates dissolving to form voids, in some cases minerals may precipitate to fill such voids [2,15,16].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
