Present Situation of Diamond Bit Used in Difficult Drilling Formations and the Development Trend

Abstract:

Great progress has been made in the research and efforts on diamond bits used in hard and compact, strong abrasive and mudstone formations. In hard and compact formation, by adding rare earth and selfsharpening materials in bit matrix and with low pressure bit structure design, the drilling speed can be up to 1.5-2.0m/h in hard and compact slipping formation with drillability less than grade 11 and the bit service life reaches 30-300m; in hard and abrasive formation, with the ultra high diamond working layer and optimized hydraulic structure design, ultrafine prealloyed powder and ultra wearresistant matrix performance, the POP and bit service life are increased by 20%-70% and 1.4-10 times respectively; in hard and compact mudstone formation, by the study on sharpteeth PDC bit and Baras bit, the drilling efficiency is increased by about 50%. For deep hard rock drilling in oil and gas field, compared with cone bit, NR826 series of impregnated diamond bit is used with screw drill, the ROP and bit service life are increased by 18%-85% and 5-8 times respectively. In addition, good progress has also been made in the research on PDC bit for offshore deep drilling in China.