Research On Real Time Calculation And Analysis Of Horizontal Well Killing

Horizontal well killing refers specifically to well killing techniques that face the reservoir.As the exploration and development of fractured oil and gas reservoirs continue to increase,failures in killings have occurred in recent years.The data analysis shows that the objective cause of the failure of well killing is the narrower pressure window in the reservoir;the subjective reason is that the pressure control accuracy of the wellbore pressure in the current throttled well killing technology is not enough.The investigation found that the difficulty in obstructing the pressure control accuracy of the wellbore of the well-killing well is:the dual uncertainty of the total amount and distribution of gas invasion;the uncertainty of the result of the overflow migration.Therefore,this dissertation focuses on the problems of initial value of killing well,active throttling model and real-time correction in order to improve the pressure control accuracy of wellbore in the horizontal well.By analyzing the dynamic characteristics of the gas-liquid two-phase flow field in the process of choking and killing wells,it is pointed out that the role of the wellhead throttle valve is a critical core issue of throttling rather than pressure reduction.It reveals the basic principle of the unification of vertical pressure and sleeve pressure in the throttling process.The basic principle of reliance pressure and annulus analysis was drafted.A mathematical model of the initial gas invasion volume based on field experiments was established,and the model-related error influencing factors were studied.A relatively high-valued technical solution for determining the initial gas invasion amount was obtained.Aiming at the pressure fluctuation problem of wellbore containing aeroelastic flow,a corresponding mathematical model was proposed and solved.The calculation results revealed that the wellbore pressure adjustment time can't be ignored objectivity,and gave up the dependence on the stress curve.Based on the real gas state equation,it is pointed out that the fundamental reason that the wellbore pressure system deviates from expectations is that natural gas forms a trapping pressure in the process of returning.The essence of throttled well killing is a dynamic process of continuously eliminating the trapping pressure.Therefore,a certain well killing instance always corresponds to a standard outlet flow curve.As long as the export flow curve according to this standard is strictly controlled,the flowback of wellhead drilling fluid is strictly controlled.The bottom hole pressure can be kept constant.The problem of the throttle opening degree directly related to the outlet flow in the killing cycle was studied.The predicted target of the active control method is the throttle opening curve.The theoretical model of an active control method for predicting and eliminating gas traps in advance based on a throttle valve has been completed.The correlation characteristics and physical meanings between different measured parameters during the killing process were analyzed,and the concept of“equivalent gas column”was proposed.It will introduce a real-time correction model to deal with polymorphic problems and further improve the accuracy of throttle adjustment.The related technology of controlled pressure drilling was investigated,and the connection between controlled pressure drilling and throttled well was analyzed,and a preliminary idea of well automation was proposed.The real-time analysis technology of throttled well killing and development well logging dynamic analysis software developed in this paper can effectively improve the wellbore pressure control accuracy of the throttle well and meet the high-precision well killing requirements of fractured reservoirs.