深井碳酸盐岩小井眼扩眼技术

WELL REAMING IN CARBONATE FORMATIONS OF DEEP SLIM HOLES

川东地区钻探目的层主要以石炭系、下三叠统飞仙关组地层为主，完钻井深大多在4000m以上，大部分井采用Ф152．4mm或Ф149．2mm钻头钻完目的层、下Ф127mm尾管完井，尾管最深为6530m。深井碳酸盐岩地层平均井眼扩大率为2．72％，实际井径为153-157mm，取心井段井径更小，套管本体环空间隙值一般小于15m。、接箍环空间隙值小于8mm，难以保证固井质量。为此，开展了深井小井眼硬地层水力式扩眼工具的研制。该扩眼工具刀翼结构与布齿技术的应用与完善，提高了深井小井眼碳酸盐岩地层的井眼扩大率，对提高小井眼固井质量提供了保障。

The major target zones of drilling in the eastern Sichuan basin are carboniferous reservoirs situated in the lower Triassic Feixianguan formation. The total depth of most wells are more than 4000 m, and φ152.4 mm or φ149.2 mm bits are often used to drill the target zone, φ127 mm liners are used for well completion. The deepest set depth of liner completion is 6530 m. In those deep carbonates formations, the average well reaming raito reaches 2.72%, the actual well diameter is 153 - 157 mm , and the well diameter at coring section is smaller. The annulus clearance around casing body is less than 15 mm, while the clearance around the casing joint is less than 8 mm, which makes it hard to ensure cementing quality. To improve well cementing, efforts have been made to develop hydraulic reamer for hard formations in deep slim holes. Through improving the structure of the reaming knife blade and the cutter arrangement, drilling operators can enhance the well reaming ratio, and ensure the cementing quality while drilling and completing deep slim holes in carbonate formations.