Early Overflow Rapid Warning Technology Research And System Design

Oil and natural gas,still as necessities in today's society production activities,theirs exploration and exploitation are extremely complex and dangerous.In this process,undoubtedly,kick accident is one of the biggest threats to safety drilling.If timely and accurate warning had been made at kick's early stage,it would reduce or avoid kick accidents,which mattered most to safety drilling.At present,though monitoring efficacy of kick accident downhole measurement method is timely,accurate and intuitive,in the ultra-deep drilling the instruments will be limited by a number of factors,such as high temperature and pressure conditions in the downhole,the terminate data transmission capacity,high monitoring cost,etc.Thus,the popularization and application of downhole monitoring technology is greatly hindered.Meanwhile,conventional ground monitoring methods have many shortcomings and limitations in precision,reliability,sensitivity and universality.Therefore,this paper proposes an early kick warning technical method with ground-based measurement which is earlier,faster and more precise than existing ground measurements.The main achievements are summarized as follow:1.Based on ground measurement instead of downhole measurement and the change of the existing kick ground monitoring mechanism,an early kick warning system was developed and matched with ground monitoring instruments and supporting data acquisition system.It realized the identification and alarm of kick accident before the overflow moved to the wellhead;2.Through the study of kick accident mechanism,symptomatic phenomenon and parameters of kick were summarized;by comparing and analyzing the capability and applicability of the existing kick monitoring method,an improved ground monitoring method of the kick accident was proposed,that was instantaneous flow of outlet monitoring method;3.In the proposed ground monitoring method,three of all factors causing instantaneous flow rate change except the factors of bottom kick,that were the effect of fluid thermal expansion,mud pump displacement change and annular cuttings concentration change,respectively,were analyzed deeply to exclude interference in the kick monitoring and improve the accuracy of the monitoring system.4.According to the selected instantaneous flow monitoring of outlet monitoring method and the three interference factors,the system monitoring parameters were determined and interference elimination model was established,achieving the real-time dynamic data correction of instantaneous flow of outlet.In view of pattern recognition technology,dynamic clustering method was used to establish a kick warning recognition model and the model was simulated by using the rig site kick accident datas.The simulation analysis validated the accuracy of the model's monitoring results and provided engineering basis for the early kick accident monitoring and diagnosis.5.Based on the instantaneous flow of outlet monitoring method and the recognition model,the system general scheme was designed and hardware equipment were matched.Combining data requirements of algorithm model,supporting database for the early kick warning system was established,providing the data support for the early kick accident monitoring and recognition;6.According to the chosen algorithm model and the established supporting database,software design of the system was accomplished and finally forming a complete system named early kick warning system rapidly with its field application test in X wells in Qinshui Basin.Test results showed that the early warning system had the capability of early warning and advanced the early warning results from traditional mud logging by round 60s,indicating our system based on wellbore piston effect was earlier and faster than that of the traditional mud logging.The early kick rapid early warning system developed in this paper,broadens the application range of the ground measuring instruments in the drilling engineering,has given full play to the advantages of ground monitoring methods,reaching a good real-time warning and diagnosis of early kick with lower monitoring cost and good field application prospects.