Performance Test Of Automatic Vertical Drilling System

Automatic Directional Drilling aims to restrain the drilling path to the desirable track by imposing forces for well straightening through control system immediately when detecting the deviation of drilling hole through MWD (measurement while drilling). The conventional well straightening is done based on the deviational survey and the detection of the hole deviation after the hole has been drilled to a certain depth. The interval time between the detection and the straightening affects the drilling efficiency; unexpected well problems are frequent, particularly in the area with unstable strata. Hence Automatic Directional Drill has become a trend for the research on drilling technology, which has witnessed tremendous development in foreign countries while we are declined the access to due to the privacy policy. In the hope of filling the technological vacancy in this field and boosting the development of our drilling technology, the research group on "Computer-aided Automatic Vertical System" made great endeavors in in-depth research of the technology and has worked out a model machine.The system is composed of four basic units respectively for deviational survey, signal transmission, control and well straightening. The deviational survey unit measures the parameters of the apex angle and the azimuthal angle of the bore hole; then the signal transmission unit send the parameters to the control unit and receives the control instructions; the control unit compares and process the message received, measure the deviation between the actual inclination angle and the verticality and send control instructions to drive the well straightening device, which then imposes an appropriate resultant force vector directing upward and keep the drilling tool moving in the vertical direction. The four units are integrated and dependent on each other. Problems with any unit will impair the performance of the whole system, which makes it quite necessary to test each of them. The absence of any technological and theoretical guidance and the limitation of our processing technology also justify the necessity of scientific and strict detail test and whole test of the system to check whether our theory and design are sound and the processed parts fit the system well. In all only through test can we find the existing problems and optimize the system design and the technological parameters.The stability of system pressure is a key issue for the system. Based on the system's basic theory of operation, the causes of the system instability are explored by analyzing whether unstable pressure fluctuation occurs in the holding power of...