Interpretation Method Research On Multi-segment Well Test After Horizontal Well Fracturing

Aiming at solve the problem of evaluating the production of each stage in horizontal well after multi-stage large-scale fracturing.Using the method of superposition and integral based on consequent point source model under different boundary conditions,we obtained three types of fractured horizontal well flow model: uniform flow rate,infinite conductivity fracture model and finite conductivity fracture model.Based on these three fractue model,using the discrete fracture units,superposition joined permeability interference between the fractures,established the well test mathematical model of infinite conductivity and finite conductivity in fractured horizontal well;large volume fracturing in tight oil reservoir formed a complex fracture network,take the way of two zone complex model equivalent the transformation zone of horizontal wells,established horizontal well volume fracturing permeability mathematical model;for multi-segment well test of fracturing horizon wells,analyse the flow mechanism during process of single card tests,established multizone linear composite multi-segment well test mathematical model.Through the analysis of the influence factors of the typical pressure curves of inner the segme nt and outer the segment,the parameter interpretation steps are determined.According to the problem of long range date of dynamic analysis,large flow data,long computing time,we proposed fast calculation model for production dynammic analysis of fractured horizontal well,based om quasi stable flow characteristics and material balance principle,we established the dynamic production characteristic analysis methods.Based on the Blasingame typical chart and dynamic material balance analysis method estimation of single well controlled reserves,we studied a software which can integration analysis and prediction the production;we carried on the Q5,P2,Z5,a total of 3 wells production data analysis and interpretation,we obtained reservoir permeability a nd single well controlled reserves,etc.the predicted results and the actual dynamic data validated by the rate of 70%;we developed the heterogeneity of fractured horizontal well model,at the same time,to achieve multi-segment production contribution ra te prediction,multi-segment fracturing production prediction and fracturing fluid flow back data interpretation analysis.We carried on Q5 well,A1 well,Q2 well multi-segment production contribution rate,compared with tracer test results,the coincidence rate reached more than 70%.We established production data interpretation theoretical chart,and analysed the influence of permeability,fracture half-length,fracture interval,fracture number,well control radius.Studied the horizontal well staged optimization strategy;put forward reasonable matching fracture with length and segmentation interwal recommended fracture interval / fracture length ratio of 0.8~1.