The Tight Gas Reser Voir Classification Evaluation Of Second Member Of Yingcheng Formationin In The Yingtai Area,Songliao Basin

Yingtai area is located in the south of Songliao Basin.The reservoir of second member of Yingcheng Formation in Yingtai area is pyroclastic rock and volcanic lava chiefly.The lithologic character and facies change quickly and pore structure and poroperm relationship are complex.Use the results of sedimentary facies and fissure comprehensively,the paper researched reservoir characteristic of second member of Ying cheng Formation,then divided three deposit units into twelve sand groups.The lower limit of physical property and electric property is based on gas-water identification,which can achieve the accuracy of the reserve parameters and obtain the reservoirplan e distribution laws.In the process of reserves calculation,due to the low level of well control,uneven distribution of well pattern,the sand groups can be divided into calculation unit.According to certain principle to delineate the gas bearing area,this paper used the triangle net of well spacing weighting method to calculate the average effect ive thickness more reasonable and through the volume method to compute the geologic reserve of second member of Yingcheng Formation in Yingtai area.Combining the present situation,the existing data in the study area this paper chose pressure drop method and unstable production method to calculate the single well production movable reserves.According to the parameters ??h movable reserves will be splitted to eac h group and total movable reserves is determined.On the basis of the core data,pore structure,log interpretation and dynamic data such as gas test,Reserve evaluation index system is built.This paper adopted many kinds of comprehensive evaluation method and redefined the binary distribution of qualitative indicators for determining weights.The R type was transformed into the S type to get the relatively accurate comprehensive evaluation value.Finally the reserve of Yingtai area is divided into three categories by stepwise regression analysis and corresponding parameters criterion is established.This classification combined with fracturing technology to meet the actual demand of gas reservoir development in this are a,which is coincided with gas test data and production situation.This paper synthesize s above evaluation standards to evaluate developmental condition and deliverability of each category of reservoir detailedly,with a wide practical value.