Development Of Double Electric Drill Pipes For An Innovative Rotary Steerable System With An Electric Drive

The depth of exploration and development(E&D)of oil and gas resources continues to increase with the great demand for oil and natural gas.In order to increase the production of single wells and reduce the cost of oil and gas production,the number of directional wells such as horizontal,multilateral and extended reach wells(ERW)is increased.Additionally,accuracy of borehole trajectory the control is becoming higher and higher.With this background,various equipment for improving the construction accuracy and efficiency of directional wells continue to appear.Among them,the most widely used is rotary steerable system(RSS)with a hydraulic drive.To communicate surface and downhole equipment mud-pulse telemetry(MPT)is used.This communication method has low propagation speed,small amount of uploaded data,and low transmission accuracy.Additionally,it can be destroyed by high bottom hole vibrations and shocks easily.In order to improve the data transmission speed and overcome the shortcomings of MPT,the wired drill pipes(WDP)transmission method appeared.Nevertheless,a lithium battery for power supply of WDP needs to be installed in the drill string to ensure the signal strength and transmission quality.Because of the limitation on the temperature and operation time of lithium batteries,the adaptability of this transmission method is limited.In order to improve the data transmission speed,accuracy of the well path,and remove restrictions of the transmission method in high pressure and high temperature(HPHT)conditions,the development of a new generation of RSS is imminent.The dissertation project presents the development of double electric drill pipes and proposes a conceptual design of a new RSS generation with an electric drive.The thesis starts with literature review and more than 150 articles of directional drilling equipment were analyzed.The electric drill,the RSS with a hydraulic drive,and the data transmission method of the WDP are detailed.The research and development(R&D)results,scientific and technical status,advantages and disadvantages of different directional tools are presented.Analysis and comparisons of these tools were performed.The main research goals:(1)design of a double electric drill pipe for the RSS with an electric drive;(2)modelling 3D models and building a prototype of tool joints of double electric drill pipes for practical research;(3)creating a laboratory test bench for the experimental research.Research content.Research activities include modeling a 3D model of a double electric drill pipe in the SOLIDWORKS? program.The 3D model was tested for deformation of static and dynamic loads,similar to borehole conditions.The tool joint prototypes with installed electrical contacts as part of laboratory research was built.Research method.Laboratory test-bench equipment was created for conducting experiments.This purpose is to determine the sealness of the tool joint connection and measure the insulation resistance of the cable cores.During the experiment,readings of changes in pressure,temperature and vibration at five measurement points rose stepwise.The vibration indication was recorded continuously.Research results.The tightness of external shoulder "metal to metal" of tool joint with the embedded electrical contacts have shown their reliability under influence of different vibrations,temperatures and pressure.The new design of the current lead to the electric motor has successfully passed experimental laboratory tests.This is confirmed by graphical and experimental measured data.Key innovations.The research work includes a new technical solution of designing a new generation of RSS with an electric drive and testing a current lead prototype under laboratory conditions.As part of the research work,three patents for the invention were obtained.This type of equipment is of great interest for studying automation and remote control of the drilling operations.International cooperation.An international scientific and industrial cooperation was concluded between the Russian Federation and the People's Republic of China to develop RSS with an electric drive.Experemental conduction,the manufacture of tool joints and the purchase of laboratory equipment were carried out with the support of the Chinese company Sun's World(Jiangsu)Oil and Gas Engineering and Technology Co.,Ltd under the supervision of the China University of Geoscience in Beijing.