Theoretical And Applied Research Of Intelligent Drilling System Base On Intelligent Drill String

Intelligent Drilling system(IDS)is a kind of advanced drilling system which is formed by combing Artificial Intelligence(AI)and drilling engineering.It is divided into two kinds of broad sense and narrow sense intelligent drilling system.From the perspective of the function and integration of system,narrow sense intelligent drilling system is more close to the current drilling technology and has more short-term value.The IDS based on the intelligent drill string refers to the drilling system which has the function of full-duplex communication between suface and downhole,real-time display and processing of while drilling data,along wellbore sensor measurement,ground control of the downhole tools and is build on the basis of intelligent drill string as a data transmission channel.This dissertation conducting the research and design of IDS based on the intelligent drill string from the aspects of system composition,wired drill pipe manufacture and reliability study,communication system design,measurement while drilling along the wellbore and test respectively.The main contents are as follows(1)This dissertation nalysis the basic component of IDS and design the structural framework of IDS based on the intelligent drill string.The system is composed of 13 of the functional modules and realizes real-time data exchange between ground and downhole,improves the ability of real-time diagnosis of complicated conditions in drilling process and wellbore trajectory control at surface,extend the use time of downhole electric equipment and so as to improve the drilling efficiency and reduce the drilling cost.(2)This dissertation compare the advantages and disadvantages of the four kinds of transmission structure of wired drill pipe in intelligent dril string system.The four respectively are cable,fiber,soft joint and rigid joint.The hard joint structure has low cost,large flow area and the easiest way to achieve.The dissertation designes wired drill pipe with the two kinds composite tube and double-layered tube structure and conducts trial production and reliability experiments of it.The wired drill pipe with double-layered tube structure resistance to internal pressure greater than 25MPa in the seal test and its wire insulation resistance is greater than 10M? under the 500V voltage in the insulation test,it has the very high sealing and insulation reliability.This provides a basis for the design and application of wired drill pipe.(3)This dissertation designs the conducting ring structure with cylindrical contact way,finds out the factor axial force F which affecting the plastic deformation of conductive ring in the process of the shackle of the drill pipe,and uses the finite element analysis method to make the numerical simulation about the stress state of the single conductive ring when the inner ring and outer ring contact with each other.When the amount of interference of conductive ring is under 0.024mm and the junction surface taper is more than 1:5 in the processing of concdctive ring,the conductive ring would not produce plastic deformation in the process of the shackle of the drill pipe.(4)This dissertation analyzes the signal transmission characteristic of the intelligent drill string transmission system and the applicability of Controller Area Net(CAN)bus as the cable in intelligent drill string.Twisted-pair cable structure of CAN bus is suitable for it as as the cable in the wired drillpipe.The transmission distance of CAN bus is up to 10km in theory and is suitable for the data transmission in ultra deep well.Its extendable nodes are suitable for for multipoint sensor measurement technology along the wellbore.The dissertation designs the communication system with CAN bus as the downhole network,the microprocessor as the lower machine and the ground computer as the upper machine.The programed communication softeware of intelligent realizes the serial communication between computer and the data transceiver module,and the well track control and the downhole drilling parameters can be displayed in real-time.(5)According to the wellbore multiphase flow model,this dissertation sets up the arrangement principles of sensors along the wellbore,and arranges the 36 sensors at the 9 position of intelligent drill string for sensitivity in the the overflow and lost circulation incident.The results show that the sensor sensitivity varies with its precision and annulus parameters and distribution regularity.According to the basic principle of soft sensor,we established real-time prediction model of overflow by using the real-time measurements at the pressure sensor nodes along the intelligent drill string in managed pressure drilling.The model accurately predicted the overflow size and location within 100s after the overflow occurs.(6)Establishment of IDS applicability evaluation scheme based on intelligent drill string points out the importance of multilevel multidisciplinary approach in intelligent drilling system.Under the instructions,analysis results show that this scheme can effectively adjust the directed force size of the rotary steerable system,improve the well trajectory control quality in a short time;the best display about the real-time data is that data,time and depth of well are measured simultaneously.The theory,method and design scheme of IDS based on intelligent drill string proposed by this dissertation enrich the theoretical system and the research content of domestic intelligent drilling system and has the positive significance to the further research of intelligent drilling.