Study On Optimization Of Fracturing Technique Parameters For Poor Reservoirs In Songshulin Oil Area

Songshulin oil area whicn entered the late stage of oilfield development is a lithologic reservoir with low porosity and ultra-low permeability.It has been restricted to increase oil production through conventional reservoir development.Therefore,the poor reservoir has become a new object of development,but in order to improve the single well production and fracturing efficiency of the poor reservoir.In order to find out the optimal fracturing parameters and fracturing construction parameters,it is necessary to study the fracturing construction technology of the poor reservoir in this area.Firstly,the rock mechanics parameters and in-situ stress in the study area are analyzed and calculated by using basic data such as core and well logging,and the previous fracturing data are sorted out and analyzed.The single well fracture characteristics and regional fracturing operation parameters are obtained,which provides technical basis for the later optimization of fracturing parameters.Secondly,empirical chart method,proppant index method and numerical simulation method are used to optimize the fracture parameters,and the optimal fracture parameters are obtained by comparising the results of these three methods.Thirdly,by putting forward the fracturing technology for poor reservoirs,the fracturing parameters such as pre-fracturing fluid volume,sand fluid ratio,sand volume and sand carrying fluid volume during fracturing construction are optimized by using FracproPT,and the optimal construction parameters are obtained,and the final fracturing fracture shape is simulated by using this software.Finally,through theoretical formula method and multiple regression method,there are seven methods to predict the productivity of fracturing.The following research results are obtained for the poor reservoir fracturing technology in Songshulin oil area:(1)The principle of selecting reservoirs for poor reservoir fracturing and the fracturing technology suitable for poor reservoir are put forward;(2)A complete set of methods for calculating the rock mechanical properties and in-situ stress parameters of poor reservoir are proposed,and the rock mechanics profiles of wells S604 and Z103 are calculated and drawn up;(3)The optimum fracture parameters of poor oil zones in well S743-4 are selected.The fracture half-length is 60 m and the fracture conductivity id 166 mD·m;(4)The optimum construction parameters of poor oil zones in well S743-4 are as follows:pre-fluid volume is 6.5 m3,accounting for 15%of the total fluid volume;sand carrying fluid volume is31.2 m3;sand loading volume is 6 m3,and the sand ratio is 15%;construction output volume is1.8 m3/min;(5)The calculated productivity is 0.62 m~3/d for the poor reservoir section of well S743-4 by various production prediction methods.Through this study,a systematic research method is provided for the optimization of fracturing parameters to the poorl reservoirs in Songshulin oil area,which is helpful to guide the fracturing construction of poor reservoirs in this area.