The Rules Of Distributions Gas And Water In Upper Palleozoic Lower Shihezi Formation Of The Area Of Shiguhao

The area of Shiguhao in the north of exploration area Hangjinqi,the gas reservoir is tight sandstone. This thesis bases on foregone research findings and accords to geological data, seismic data wells, logging data,outcrop data and so on which in order to introduce reservoir forming geological characteristics and studying in the characteristics of underground water the rules and main controlling factors of gas and water to underlie reservoir forming mechanism. According to above researchs I get following researching results.Firstly, exploring area produces tight sandstone gas reservoir, which is full of source rocks(Shanxi and Tianyuan formation) and main on coal measure strata with stable thickness. Reservoir condition is good as well(upper Shanxi and middle and lower Shihezi formation). Main reservoir deposits the sedimentary facies of braider river alluvial fans and the sand of delta deposits, which with a high textual and component maturity, is belonging tight sandstone reservoir. The cap corks have stable thicknesses, which mainon clay minerals with a strong close ability. The area with single structure and complete strata makes a good relationship between reservoir and cap rocks, with which having a good potentiality of exploring and developing.Secondly, as the standard of mineral content of water to classify the tape of formation water, according to analyze the water chemical characteristics to strike up distribution pattern of formation water. The area of formation water is influenced by condensate water with a lower number of mineralization of water and the PH value is mostly less than 7. The formation water with a better close is also influenced by under formation water, which has a higher content of Mg2+. The zone with a good reservoir condition of hydrocarbon of which geochemical anomaly is influenced by foreign fluid.Thirdly, according to combo the theoretical models with the regional actual situation, which chooses the representative wells using sometong about mathematical geology methods to establish the models to distinguish water or gas in the low Shihezi formation. We can be sure to distinguish water lays, dry lays, gas and gas with water lays as a standard of which throught combining intersection graph method, differential resistivity methods with multivariate discriminant method.Fourthly, thought the above studying we use seismic data, logging data and to return to each structural small lays, which establishing combined well profiles to establish each lay of water lays, dry lays, gas and gas with water lays of which distribution and characteristics of the profile. We use sedimentology knowkedge to be sure them distribution and characteristics of plane.Combining distribution and characteristics of plane with of profile, we can find that there are three main controlling factors to distribution of gas and water; structure, distribution of reservoir sand bodies and distribution of abnormal pressure.Finally, combining above findings with relating theories of petroleum geology we can analysis on the main factors of natural gas accumulation and accumulation throught structure, distribution of reservoir sand bodies and distribution of abnormal pressure.