Basin Fluid Flow and Associated Diagenetic Processes

Key words: 
• basin fluid /
• diagenetic process

Abstract: Basin fluid flow will change a diagenetic condition including temperature, pressure and fluid geochemistry in a pore space of host rocks, and result in the variation of sequential diagenetic processes, interaction of water and rock, and porosity of reservoir. Viewing in siliciclastic rocks, fluid flow only results in dissolution of minor mineral and modification of pore space due to mineral dissolution and precipitation. Fluid with plentiful of CO2 and organic acid will provide an available condition for the development of secondary porosity. Fluid episodic expulsion in overpressured environment not only results in the formation of secondary porosity in the overpressured compartment, but also results in the occurrence of abnormally diagenesis due to perturbations in temperature in shallow reservoirs with a hydrostatic environment. Viewing in carbonate rocks, because of strong dissolution of carbonate rocks, basin fluid flow can result in an essential variation in fabric and pore space in carbonate reservoirs. Expulsion of metroric inleakage and deep volcanic or hydrothermal fluids along faults or fractures will result in an essential variation in composition, texture, reservoir space in a vast realm in carbonate rocks. Hence, weathering karst typed and structurally controlled hydrothermal dolomitization typed reservoirs related closely to basin fluid movement are taken as main reservoir in carbonate rocks. However, basin fluid flow and associated diagenetic process has remained a matter of controversy, much more research are needed in the future.