Analysis of Influential Factors on Wireless Electromagnetic Short Transmission Module in BH-VDT Vertical Drilling Tool
The vertical drilling tool+high-torque screw integrated ROP improving technology is the main means of deflection control while fast drilling in high steep piedmont structures.The BH-VDT vertical drilling tool adopts an integrated design of measurement,control and real-time upload while drilling,but it is currently chal-lenging to efficiently transmit near-bit acquired information to the ground by bypassing the screw.In this paper,the pulse generator was separated from the tool and replaced by a wireless electromagnetic short transmission mod-ule,wireless emission module and wireless receiving module were connected at both ends of the screw,and the fi-nite element analysis software was used to build a drilling test model to analyze the factors affecting the wireless e-lectromagnetic short transmission module.The simulation results are in good agreement with the field test data.When the distance between the positive pole of the receiving antenna in the wireless electromagnetic short transmis-sion module and the bottom of the casing is greater than 20 m,the shielding effect of the casing on the received signal strength tends to be gentle.The drilling fluid resistivity and formation resistivity have significant impacts on the wireless transmission effect of this module;the longer the insulation distance between the two poles of the re-ceiving antenna,the more favorable it is to the transmission effect.When the distance between the transmitting and receiving terminals is 8～15 m,the impact on the received signal strength is relatively small.The results show that the wireless electromagnetic short transmission module is an effective solution to real-time efficient transmission of downhole information in the BH-VDT vertical drilling tool by bypassing the screw,and has guiding significance for the design,phenomenon interpretation and use of other tools to solve such problems.
vertical drillingwireless electromagnetic short transmissiondipole antennaresistivityre-ceiving source distance
NETL
NSTL
万方数据
维普
