Research and application of special-shaped tooth PDC bits in Bayanhetao New Area

Abstract:

For the efficient development of oil and gas resources in Bayanhetao New Area， research has been conducted on special shaped PDC bits. Based on well logging data， core assay and actual drilling data， the lithology analysis of the strata in this area is carried out， and finds that the drillability of the strata in the deep Cretaceous and the Archean gneiss strata is poor. The drilling results of special tooth bits in poor drillable formation in this area and the outer blocks are investigated， and show that the footage per bit in Cretaceous strata below 5000m and the Archean strata is small with low mechanical drilling rate， while drilling speed is remarkably increased in the Tarim Tahenan difficult area. The rock breaking mechanism of plane teeth， axe teeth， polygonal teeth and conical teeth is compared and analyzed， which provides theoretical support for subsequent optimization design of drill bits. Field tests were carried out on special-tooth bits， which significantly improved the penetration and ROP compared to conventional PDC bits. Twenty-one of the wells achieved “one-trip” drilling for the second well section with a total footage of more than 30000m. In short， according to the formation drillability， to improve the drill bit and formation compatibility through the optimal matching of plane teeth， axe teeth， polygonal teeth and cone teeth can significantly improve drilling efficiency.