A Study On Hydraulic Fracture Evaluation Of Low Permeability Reservoir In Wuliyasitai

Wuliyastai Block in Erljan basin is a glutenite reservoir,which has the characteristics of low permeability and porosity,serious heterogeneity,low productivity,low grade reserves,etc.In view of these,it is required for large-scale hydraulic fracturing.However,after the fracture,many problems have arisen,such as production declining fast,low oil recovery and so on.These issues have serious implications for effective use of the reservoir.In response to these issues,experiments,mathematical methods and numerical simulation have been used,which can measure the permeability and porosity,evaluate the reservoir sensitivity and the performance of the fracturing fluid and assess the fracture parameters.This paper analysis the main factors of the fracturing effect by three areas: reservoir physical properties and characteristics,fracture fluid and fracture parameters.Through these fracture method and design can be optimized.The research results are as following: By doing experiments of permeability and porosity,we clarify the range of permeability and porosity value.According to the sensitivity experiment results,the reservoir has serious water sensitivity and stress sensitivity.The fracture fluid do not cause much damage to the formation and its viscosity can stand high temperature.The sand-carring time and the gelout time can meet the requirements of the field.Subject to data and statistics of fractured wells,we come to the conclusion of optimal ranges of construction parameters.By using different mathematical methods,we can see the impact of geologic and construction factors on the production of fractured wells.Mathematical simulation software has been used in this paper.It gives us a better understanding on fracture parameters.By means of FracproPT software,we find that the parameters are almost smaller than the fracture design data.The main reason is that the difference between the reservoir and interlayer is too low to control the fracture height.The research in this article make us gain the informantion on current state of reservoirs and find out the main influence factors of fractured production.This paper aim at providing support for the follow-up study,making contributes to improve the development effect of wuliyasitai reservoir.