Study And Application Of Rock Physics Properties In Chunguang Oilfield

Chunguang Oilfield lies in Chepaizi area,which belongs to the West Junggar Basin.A body of differ-in-sized and lithology-related oil reservoirs has been successively explored in Chunguang block’s multi-series of sandstone strata like Shawan formation,Paleogene and Cretaceous.The existence of large changes of the reservoir physical property,little wave-impendence discrepancy of sand-mudstone,thin interconnection of sand-mudstone as well as the Geological conditions with complex oil-water relationships in part of the well area put a severe restriction on hydrocarbon detection.With the introduction of rock physics,we designed rock microcosmic characteristic experiments for rock samples including conventional physical testing,whole rock analysis and cast sheet.Through these depth and meticulous research,we have a comprehensive understanding of mineral composition,cement and diagenetic characteristics and pore structure of these rocks.It can be used in discussion of the master factor about reservoir rock physical properties.According to the elastic parameter test,combined with physical property and logging data analysis,we can get a regular summary about reservoir rocks and analyze wave velocity change trends in different temperatures and pressures.The relation between physical property and elasticity is also studied.We compared conventional empirical models and fitted-empirical models,includes velocity-porosity model,density-velocity model,Vp-Vs model.At the same time,we carried out the analysis of petrophysical experiments about loose sandstone in Chunguang block.Considering the influence of pore fluid,we measured the velocity of fluid-saturated rocks.The elastic parameter shows a discrepancy after the rock is been saturated.By calculating and intersectional analyzing different attribute-sensitivity of fluid,we determined sensitivity parameter and parameter combination,which can be used in fluid identification.In the analysis of microcosmic and elastic properties in both cemented and loose sandstones,with the comparison of theoretical calculation and experimental results,we chose combination model to quantitatively characterize the dynamic law of seismic elastic properties by selecting proper model parameters.For loose sandstone,we chose lower Hashin-Shtrikman bound and Hertz-Mindlin model to quantitatively characterize the seismic elastic properties affected by sorting.For consolidated sandstone,we selected critical porosity-modified Hashin–Shtrikman model.The result indicates that the combination model well characterized the porosity-velocity relations of sandstones in Shawan formation.System analyze the member 1 of Shawan formation and the member 2 of Shawan formation with several wells,And obtain the alluvial fan deposition system and braided river-delta deposition system Logging data show the rock physical characteristics.And the establishment of the corresponding rock physical template,in order to reverse the qualitative or quantitative interpretation to lay the foundation.