Ordos Basin HuaQing Areas Such As White 254 Seven Wells 8 Reservoir Sandstone Of Extended Leader Petrology Features Study

This article through to a lot of casting body chip, grain size analysis, scanning electron microscope, cathodeluiminescence, clay mineral and X-ray diffraction analysis -- tests and have a lot of information and data , In sedimentary theory, clastic reservoirs as basis, combining research international oil exploration of new achievements, In JiYuan - HuaQing region's big geological background under, Select HuaQing area relatively important, with typical features of seven Wells, white white 254 269, white 275, white 279, white 280, white 285 and sixth 70, China celebrates the areas extend long 8 groups reservoir sandstone reservoir petrology characteristics were studied.Petrological characteristics is the study area since the birth of diagenesis clay minerals material foundation, is also sandstone reservoir property and capacity of a basic conditions or. HuaQing areas such as white 254 seven Wells rock types include feldspar sandstone and feldspar quartz sandstone and feldspar lithic sandstone, debris feldspar sandstone and lithic snastone five types. In this five types, with debris feldspar sandstone and feldspar lithic snastone as its main types. Component maturity is poorer; Sandstone is generally fine granularity, with fine sand for the Lord; Sandstone is good, roundness sorting for times edges. These seven Wells of the sandstone chip for the average miscellaneous base content 3.29%, much lower than the sandstone classification of 15% of the miscellaneous and miscellaneous sandstone, suggesting that HuaQing area content in the seven Wells for its main sandstone net sandstone. In the seven Wells selection of base types mainly water mixed with mud iron primarily, mica respectively 1.28% 2.01% and content, and two other miscellaneous mix layer and yankees HuaQing region in gray clay in the seven Wells content of 0. HuaQing areas such as white 254 seven Wells that the cementing 11.84%, except for the types of total thing thought, also cementing carbonate includes siderite, anhydrite, siliceous cementation content, long stone, a small amount of pyrite and bituminous. Several common cementation content, carbonates cementation content for 9.23%, accounting for most of the content of cement proportion; Siliceous content for 1.74%, iron content is less.Among the findings, this seven Wells authigenic mineral including chlorite, kaolinite, illite and mixing layer illite/smectite four. Illite in the content in the object of study is very high, but slice observation and electron microscopic observation shows that the formation of illite and blending layer illite/smectite is very limited in quantity, suggesting that most of these two kinds of clay minerals are miscellaneous base form existence, rather than on authigenic mineral forms exist in sandstone. In addition, the seven main Wells mouth lower total face rate for 1.14%, average, they in prolonging the sandstone reservoir group leader and pore type is diversiform, evolution mechanism complex, its pore types include primary pores, secondary porosity and micro fracture types, only see a small amount of microscopic primary porosity. Since the existence of life chlorite, strengthened the compressive real ability of sandstone, compaction effect has certain inhibition.Ordos basin HuaQing areas such as white 254 seven Wells in extended leader 8 reservoir pore, as the lining of the chlorite what protect mainly primary between grains in sandstone reservoir pore, pore lining as the content of since birth chlorite are mainly for and between grains pore positive correlation between. And kaolinite causes and feldspar, but about the dissolution of the porosity and kaolinite than positive correlation, explains chlorite pore is not directly to kaolinite protective effect.