| Hang's mudding-off technique is an important measures of increasing the height of the column by filling the well with drilling fluid,maintaining the dynamic balance of the well pressure,and obtaining the safe working time in the drilling operations occurred after the loss.Conventional hang's mudding-off technology is an empirical approach,the project site called"blind hang".The optimization of the hang's mudding-off technology needs a systematic theoretical analysis and calculation methods,in order to fundamentally solve problems of"blind hang" caused well control safety.According to the actual conditions of hang's mudding-off technology,based on the dynamic analysis method of wellbore leakage,the mathematical model of the change rule of the annular surface of the wellbore is established,and the statistical method of the leakage function is established to analyze and calculate the reasonable hanging height and the safe operation time of the hanging water,and providing scientific reference for project site implementation of.hang's mudding-off technology;At the same time to provide a new type of hanging tank design,and for the use of new type of hanging tank to regulate the use of hanging technology to form a complete set of optimized hang's mudding-off technology,it is of great practical significance to provide a solution for the major problems in ensuring the safety of well control.The main contents of this paper are as follows:(1)Dynamic analysis of hang's mudding-off processBased on the analysis of the principle of hanging technology,combined with the theory of conservation of quality and segment analysis,the physical model and the physical model are established respectively.The models are established respectively after the effective height of the annular surface,the safe working time and the annular cross-Mathematical model,theoretically solve the blind hanging problem.(2)Leakage function determination methodCombined with the liquid surface monitoring technology,through the real-time monitoring of the depth data in the wellbore,the mathematical function analysis method is used to determine the loss function of the relationship between the leakage rate and the leakage pressure.(3)Analysis of influencing factors of hang's mudding-off technologyUsing the calculation example,the reliability of the three mathematical models of the hanging process is tested.According to the calculation results,the influencing factors such as the density of the drilling fluid and the amount of the drip irrigation are analyzed,and the analysis results can provide the theoretical basis for the field sinking operation.(4)Research on Matching Technology of HangingThrough the structural design and finite element analysis,the design scheme of the new mobile jacking tank is put forward;at the same time,combined with the use of the new mobile hanging and overhead tank to study the process of hang's mudding-off,the formation of a complete set of optimized hang's mudding-off technology for the well leakage back to the conditions to ensure well control safety to provide a major solution to the problem.Through the study,this paper draws the following conclusions:According to the actual conditions of hang's mudding-off technology in this paper,the physical model and mathematical model of wellbore annular surface variation are established by using the dynamic analysis method of wellbore leakage,the effective height of annular surface,the safe working time,for the implementation of reasonable "hang's mudding-off"to provide a scientific theoretical calculation method.(2)Based on the effective height and safe working time mathematical model,the integral results of various leakage rate are given,which are used to analyze and calculate the effective hanging height and the safe operation time;and for the composite annulus section,the use of sub-processing,step by step sum of the calculation method,in order to solve the problem of changing the inner diameter of the casing and changing the outside diameter of the drill pipe,it provides an effective means.(3)In this paper,based on the principle of mathematical statistics analysis,a data fitting method based on real-time monitoring data of annular surface depth and time relationship is proposed to determine the loss function,and the example is calculated,the results are highly consistent,indicating that the method can use the liquid surface monitoring data to determine the best loss function.(4)Based on the calculation example,the reliability calculation model of the safe operation time and the effective height calculation model of the hanging,the error analysis shows that the calculated results are in good agreement with the actual data,full description of the safe operation time calculation model and the effective height calculation model of hang's mudding-off can be used for engineering actual calculation.(5)The analysis of influencing factors of safe operation time of hanging water shows that:appropriate increase in the amount of hanging can increase the safe operating time;reducing the density of the drilling fluid can also increase the safe working time properly.(6)In this paper,the structure of the new mobile turret placed in the drilling platform was designed,and the strength design is carried out by using finite element analysis,and the components and methods of hanging measurement are designed,which can provide feasible solution for the implementation of gravity hanging on modern deep drilling rig.(7)In this paper,the use of new mobile overhead tank to carry out gravity hang's mudding-off process were discussed,and discussed the safety protection of the anti-spray tool in the drill string during the process of hanging,and formed a complete and optimized"hanging" technology to provide a solution for the major problems in ensuring the safety of the well. |
PDF Full Text Request