Research On The Analysis Method Of Transient Production Decline For Single Well In Carbonate Multi-media Reservoir

Advanced production decline analysis,as one of the conventional monitoring technique has become more and more popular among researchers.Nowadays,for carbonate reservoirs,most research about production decline analysis is performed on the Blasingame theoretical models,with little to no research on the Transient theoretical models.However,the Blasingame theoretical model is based on boundary dominated flow.The interpretation results will be inaccurate,even deviate from the reality when test curves failed to display a boundary flow regime.In this paper,a new production decline analysis called Transient is studied for the multi-media carbonate reservoirs.As a result,the matching effect of the Transient theoretical models is desirable and the corresponding interpretation results are credible,which break the limitations of the Blasingame methods.The main contents of this paper are summarized mainly in the following aspects:(1)For the dual porosity reservoir with fracture-matrix system,the Transient models based on the effective radius which consider dual porosity and single permeability,dual porosity and dual permeability are established and the corresponding type curves are gained.The sensitive characteristics of type curves for model parameters is especially studied,which include fracture storage coefficient,inter-porosity flow coefficient of matrix to fracture,boundary radius and fracture skin.(2)For triple porosity(fracture-matrix-vug)reservoir,the Transient models based on the effective radius considering triple porosity and single permeability,triple porosity and dual permeability are established and the corresponding type curves are gained.The sensitive characteristics of type curves for model parameters is especially studied,which include fracture storage coefficient,inter-porosity flow coefficient of matrix to fracture,inter-porosity flow coefficient of vug to fracture.(3)For two-zone composite reservoir,the Transient models based on the effective radius considering the first zone is dual porosity formation and the second zone is homogeneous formation,the first zone is dual porosity formation and the second zone is dual porosity formation are established and the corresponding type curves are gained.The sensitive characteristics of type curves for model parameters is especially studied,which include composite radius,mobility ratio and diffusivity coefficient ratio.(4)For two-zone(fracture-vug-matrix)composite reservoir,the Transient models based on the effective radius considering the first zone is triple porosity formation and the second zone is homogeneous formation,the first zone is triple porosity formation and the second zone is dual porosity formation are established and the corresponding type curves are gained.The sensitive characteristics of type curves for model parameters is especially studied,which include composite radius,mobility ratio and diffusivity coefficient ratio.(5)Production decline analysis for example wells,four wells are chosen to analyze with the type curves of Transient models,and the comparison between the interpretation results of the Transient method,the well test method and the Blasingame method is conducted.