Research And Design Of Real-time Dynamic Early Warning System For Fracturing

Fracturing is the most effective and fastest approach used for production increment in low permeability oil fields.Due to the complexity of fracturing conditions,there are considerable risks in fracturing operation,and bridge over is the most important factor leading to the failure of fracturing,It seriously impedes the normal operation of fracturing,results in repeated operations,and reduces the efficiency of fracturing,leads to a huge waste of resources,even causes fracturing string scrapped and construction accidents.In addition,whether the fracturing cracks extend in accordance with the designed requirements is also a key factor that determines the success or failure of fracturing.Therefore,this paper proposes a set of fracturing real-time and dynamic warning method and auxiliary system,which integrates bridge over risks real-time early-warning model and crack real-time calculation model as a whole.The system can realize early warning of bridge over risks and real-time analysis and calculation of cracks' real-time trend in the process of fracturing,which is of great significance in preventing accidents,ensuring safety of fracturing operations,and increasing the efficiency of the fracturing.This paper presents a set of fracturing real-time and dynamic warning method which is suitable for the current situations of fracturing construction,as well as develops and integrates the auxiliary system.Results are as follows:1.A fracturing risks real-time monitoring and early-warning system that is suitable for fracturing process is developed,which achieves real-time acquisition and integration of data,accomplishes real-time monitoring and early warning of risks in fracturing,effectively enhances the success rate of fracturing,and reduces derivative accidents caused by bridge over.The system has been used for 24 wells in fracturing sites,which is proved to be well-running and accurate warning.2.Through the study on fracturing technology and occurrence mechanism of bridge over in fracturing,the affecting factors,characterization and regular pattern of bridge over are summarized,and based on which,a set of warning analysis program that is suitable for fracturing process is proposed.3.On the base of the early-warning program,evaluated,evaluation and analysis of monitoring parameters,and selection of early-warning algorithm of bridge over are finished.The BP neural-network is selected and after analyzing the results of previous studies,proposing an improved conjugate gradient algorithm,the defects of BP neural-network such as slow convergence speed,liability of dropping into local minima are eliminated,which effectively improves the convergence property and training speed.On the basis of this improved BP neural-network,a set of fracturing bridge over risks real-time and early-warning mold is built.4.Through the deep research on crack extension model and comparison of two-dimensional,quasi-three-dimensional and full-three-dimensional crack calculation model,a real-time cracks calculation model is established,which achieves real-time assessment of fracturing cracks.5.The established fracturing real-time and dynamic warning database realizes unified storage and management of multi-source data,which provides technical support for the realization of fracturing real-time and dynamic warning system.6.Based on the established fracturing bridge over early-warning model and cracks calculation model,the overall architecture design of fracturing real-time and dynamic warning system is completed,and by using SQL Server 2008 database platform and C#programming language,the development of software system is finished.Through field testing,the result shows that the system meets the needs of the sites and has the ability to promote industrialization.The fracturing real-time and dynamic warning system designed and developed in this paper sets real-time monitoring of fracturing date,fracturing data management,real-time risk warning of bridge over and real-time calculation of cracks as a whole,can provide more completed technical decision support platform for field technicians.The system has been applied in 24 wells of Petro China Huabei Oilfield Company,and runs very stably.