激情偷拍av-怡红院亚洲第一综合久久-亚洲成av人在线观看天堂无码-国产精品20p-亚洲日韩a∨无码久-国产午夜三级-韩国av免费在线观看-欧美黑人极品猛少妇色xxxxx-久久九九视频-亚洲人成网站在线无码-国产乱淫精品一区二区三区毛片-蜜桃少妇av久久久久久久-久久久综合精品-日韩午夜在线-丁香激情综合久久伊人久久-午夜性福利视频-无线乱码一二三区免费看-久久九九热视频-国内精品久久久久久久影视麻豆-国产伦精品一区二区三区妓女下载

Products & services

Hilong Double-Walled Drill Pipe

Product Introduction 

Double-walled drill pipe is composed of two layers pipes. It is mainly used in reverse circulation drilling technique. The outer drill pipe is the transmission medium of torque and pressure, the space between outer and inner pipes is a channel for pumping circulating medium to well bottom, the inside channel of inner drill pipe returns the circulating medium and rock chips to the outside.

Product Advantage

·No wash out from the walls of a well, reservoir protection, no limit to drill collapse layer and loss formation;
·Less drilling fluid, smaller displacement and faster return speed, the hole is clean;
·Unique advantage in directional well, horizontal well and continuous sampling;
·Suitable for large hole drilling, improving drilling efficiency.New drilling techniques have been developed on the basis of double-walled drill pipe, the most typical representative of it are RDM (Reel Well Drilling Method) and RCCD (Reverse Circulation Centre Discharge).

Product Specification

Size Range (OD of external layer pipe):
Normally 5", 5 1/2", 5 7/8", 6 5/8", 7 5/8", 8 1/2", 9 1/2" and 10".