Interwell Connectivity Identification And Analysis Of Low Permeability Reservoir In Block Z28

Interwell connectivity research is an important part of reservoir evaluation and the foundation of oilfield development and management.With further development,injection pressures of Z28 low-permeability reservoir developed for long-term water injection,located in the southwestern Ordos Basin,has continued to rise,the contradictions between the layers have intensified,water drive conditions has worsen,and the development situation has become severe.Therefore,identifying the interwell connectivity is the key to investigate the injection-production relationship.In order to propose an effective injection-production program,it is necessary to systematically identify and analyze reservoir interwell connectivity.Based on the fine division of the small layer of the study area,this paper used the dynamic and static methods to research the interwell connectivity.Firstly,through the analysis of reservoir grid diagrams,the method of qualitative and quantitative representation of static connectivity was established based on the control degree of waterflood and connectivity resistance of well groups.Secondly,based on the analysis of the intrinsic relationship of injection-production dynamic data,a grey correlation model and a multiple linear regression model were established,and through the in-depth study of the influencing factors of the injection signal's time delay and attenuation,a first-order linear system method was constructed,thus the multiple linear regression model was improved.Then,using the different reservoir models established,the above three models were simulated and compared,and the results show that the improved multiple linear regression model is practical and more reliable.Finally,the interwell connectivity analysis was performed using the T30-29 well group as an example,and the development project was designed based on the research results.The interwell connectivity identification method established in this paper has certain guiding significance for the low permeability oilfield water injection development.