Study And Application Of Interference Well Testing In Multilayered Reservoir

Recently,interference well testing analysis has become a valuable analysis tool in reservoir characterization of most of the oil field development projects,especially if the area between the wells has been adequately swept.Therefore,results obtained from interference data analysis show a better reservoir representation as compared to that obtained from single well test.In addition to confirm communication between wells,can estimate the transmissibility,storativity,vertical permeability and crossflow between layers.Faults can also be detected.The majority of hydrocarbon reservoirs are stratified with layers of different properties due to different digenetic history and sedimentary deposition processes.Since the individual layer properties are very important information for multilayered reservoir development strategies,especially during secondary recovery and enhance oil recovery.Many studies have focused on testing and analyzing the pressure response behavior of a multilayered system to understand and quantify formation properties.In order to lower the level of uncertainty in layered reservoir characterization.Even though,the majority of analysis methods of interference tests in layered system use single layer homogeneous model.This can result in significant errors during estimation the average reservoir properties,due to considering reservoir as uniform structure.For the fact that there are many factors influence the pressure responses of observation wells,such as anisotropy,number of layers,distance between wells and others.So this work carried out to estimate the layered properties and investigate the factors influences the pressure response at observation well in interference testing.As well as to analysis the influence of wellbore storage on the pressure response obtained from active well.In this study we employed numerical analysis approach for two layered system-in order to estimate the individual layered properties and-and analytical approach for single layer system as interpretation methods for interference testing of vertical wells in a multilayer oil reservoir with and without crossflow in the formation.The results of this study provided the layered and average reservoir propertied as well as show that the pressure responses at observation wells in layered system differ from the single layer system response.This difference depends upon the contrast in transmissibility and storage of the layers.The variation is found to be more pronounced when crossflow exist between layers.The results were also found that,as the distance between the active and observation wells increases,the variation of the pressure response from the single layer system decreases at same time multilayered system showed different response;vertical permeability has considerable influence on the pressure response at observation well when the variation in transmissibility and storage between the layers is large.As well as the layered storage was found to have obvious influences on pressure derivative response shape.Finally Considering the heterogeneity of reservoir during reservoir modeling is very important factor to estimate the average reservoir properties and to study reservoir behavior.In addition numerical simulation provides and display more important information of the reservoir and wellbore parameters than analytical solution,as well can analysis very complex conditions.