| The segmentation test model of multi-fractured horizontal well(MFHW)is an important method to determine the production capacity and reservoir properties in low permeability reservoir.Existing well test models cannot correctly interpret MFHW test data disturbed by interferences among fractures.This work develops two semi-analytical models,the injector interference MFHW model and the segmentation test model with interferences among fractures.Reservoir and fracture are regarded as a flow system.The reservoir model is established using the point source method.Fracture model is based on boundary element method(Cinco-Ley1989).Fracture model and reservoir model are coupled,and the flow rate and pressure of each fracture element can be obtained.The calculation shows that the flow distribution in the half fracture of this model presents a U-shaped distribution,and the fractures at the root and the toe of the MFHW model have higher flow rate caused by fractures' interference.After considering the interference of injector,the flow distribution changes into L-shaped type and the pressure derivative curve goes down to a stable value 0.5×(1-qin D)in the final flow phase.It can be seen from the segmentation test model curve of horizontal well that the flow rate of each section affects the shape of pressure derivative curve,the injection well position can be roughly determined by comparing the occurrence time of interference in each test section,and the injection volume of interference well can be interpreted by combining the falling value of pressure derivative curve.This semi-analytical model is verified by numerical well test model from mature business software.The interpretation of a horizontal well section test example shows that the flow rate of each test section can be divided by pressure fitting.The pressure data of test sections can be interpreted uniformly so it can improve the reliability of interpretation results and has a good application prospect. |
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