CARBONATE PORE CHARACTERISTICS, PORE COMBINATION REGULARITY IN SPACE AND GENESIS OF PALEOZOIC IN ZHUANGHAI AREA

Based on the porosity characteristics, the authors probe into the pore combination regularity in space of Paleozoic in Zhuanghai area, and explores the main controlling factors. The most important types of pores of Paleozoic carbonate in Zhuanghai area are fissure-extended fissure-erosion holes. Primary pores have disappeared, and effective reservoir space comes from secondary pores. The developed inner buriedhill reservoirs are different in oil-water boundary from those of the crust of weathering and have deep-buried karst characters; there are uniform oil-water boundaries and same erosion characters between Archean and Paleozoic; and the " upper fissure-lower hole" reservoir character of buried hill are showed in three main combination types of reservoirs in space. Secondary pores and various combination types of reservoirs in space lead to different reservoir capacities in different buried-hill zones. Multistage unconformity karsts lead to early stage corrosion pore and buried hill inner reservoir. Deep-buried karsts cause the formation of deep corrosion pore space and lead to uniform oil-water boundary and same erosion characters between Archean and Paleozoic. Neo-tectonic movement and deep-buried karsts together result in the "upper fissurelower hole" reservoir character of buried hill.