Dynamic Description Technology And Application Of Fracture-cavity Carbonate Reservoir

Fracture-cavity carbonate reservoirs have complex reservoir characteristics.In the development study,there are some problems that complex oil-water relationships,complex fracture-cavity connections,uncertain reservoir parameter values,rapid production decline and complex reservoir types.It is challenges to reserves evaluation,development plan design and development dynamic analysis.In this paper,taking the Halahatang fracture-cavity carbonate reservoir as an example,this paper studies fracture-cavity reservoir characteristics,the reservoir space type,reservoir types and fracture-cavity configuration models.And the analytical and numerical models of pressure and production of fracture-cavity carbonate reservoirs with multiple fracture-cavity configurations are built.Combined with the pressure and production model,a set of dynamic description methods suitable for the Halahatang fracture-cavity carbonate reservoir has been completed.Mainly completed the following work:(1)Research on reservoir characteristics of fracture-cavity carbonate reservoirs.The paper classifies the storage space by static means,and combine static and dynamic means to classify the type of reservoir.According to the combination relationship between the fractures and caves in the reservoir,the relationship between fractures and caves is proposed.(2)According to the transit pressure theory,mathematical models of cave type,fracture type and fracture-cavity types have been established.Taking into account the wellbore storage coefficient and skin coefficient of fracture-cavity carbonate well testing and production data analysis model,the model is solved to analyze the pressure and pressure derivative curve characteristics and parameter sensitivity.(3)Using numerical simulation methods,based on the fracturecavity configuration model,considering the permeability distribution,well location,water body and other factors,a numerical model for fracture-cavity carbonate reservoirs was established to complete the numerical well test type-curves and production data analysis type-curves.(4)Analytical models and numerical models of well test and production data analysis are applied to carbonate reservoirs in Harahatang.So,based on the analysis of 15 production wells in the Halahatang oilfield,12 wells are characterized by cave-type reservoirs,3 wells are characterized by fracturecavity reservoirs,and the reservoir type of Halahatang oilfield is mainly cave type reservoir.The well connectivity between RPX and RPY was determined.