Application Of Dynamic Kill Drilling In Complex Formation Pressure System

With the increase of the petrochemical energy exploration and development efforts in our country and the formation and structure of our country is complex, More and more complex formation pressure system will be encountered while drilling, usually accompanied by overflow, malignant leakage, narrow density window and other complex problems. The managed pressure drilling technology is an effective technical means for the complex situation of the drilling. Dynamic kill drilling is the key technology of deep water riser less drilling.It is to solve the complicated problems of shallow gas, shallow water and other complex problems. It belongs to the field of managed pressure drilling.At present, our country has already broke through the blockade of foreign technology, and started the market application, but this technology is currently only used in deep water drilling platform, not popularized Therefore, this paper attempts to apply the technology to solve a variety of complex formation drilling problems.The following researches have been done:(1) The paper has made a detailed study of the three major equipment system,auxiliary equipment, technical principle and process of the dynamic kill drilling in deep water.The current domestic dynamic kill drilling technical indicators, and the application of the status in the deep water drilling platform.(2)The paper has put forward the concept of complex formation pressure system choosing the typical complicated block-Weiyuan shale gas reservoir complex formation pressure system for the study,and analyzed of complex drilling problems faced by Weiyuan and the drilling site construction conditions(3)Targeting to the characteristics of dynamic kill drilling and land drilling environment,the paper has analyzed application adaptability of the dynamic kill drilling. According to the difference between land environment and deep water drilling established annular flow model and calculation method of bottom hole pressure of dynamic kill drilling, has been established the foundation for the dynamic kill drilling control pressure design.(4)The paper has designed the dynamic kill drilling pressure control method of calculation for pipe connection, tripping, cycle operation normal operating conditions and for vicious lost,narrow density windows, overflow complex conditions. According to the dynamic kill drilling bottomhole pressure control algorithm, using the VB6.0 compiled calculation software of six working conditions which can quickly and easily calculate the dynamic kill drilling pressure control parameters.(5)The paper has used the method of dynamic kill drilling to design pressure control parameters for narrow density windows and to the field data compared with the actual design parameters to verify. The feasibility and superiority of dynamic kill drilling has been verified after comparing.Although dynamic kill drilling is a deep-water built well technology, it can be used as a controlled pressure drilling technology to solve complex formation pressure system drilling problem afterthe process be re-optimized design with the construction condition of enough water source and heavy mud.