Dolomite Reservoir Characteristics of Lower Ordovician Penglaiba Formation,Tarim Basin

For dolomite reservoir of lower Ordovician Penglaiba Formation in Tarim Basin,the petrological,reservoir space and petrophysical-property characteristics and the factors controlling reservoir growth are studied in this paper based on core-drilled observation,thin-section identification,petrophysical-property test and geochemical analysis.It is considered that:(1) Penglaiba Formation in Bamai area,north and central Tarim Basin is almost composed of dolomite with large thickness,which mainly including silty to fine-grained dolomite and some micritic,middle-to coarse-grained dolomite;(2) the reservoir space includes intercrystalline pore,intercrystalline solution pore,solution pore and structural fracture;(3) it is characterized by strong heterogeneity and its permeability and porosity arevery different for Penglaiba reservoirs in different areas;and(4) the factors controlling petrophysical property are mainly compaction,pressure solution,cementation,recrystallization,burial dissolution,dolomitization,tectonism and weathering-crust dis solution.