Coiled tubing is called by experts as a revolutionary technology which has stirred up a new wave in oil-gas production in the 21^st century. Nowadays coiled tubing, which is up in the ascendant, has been applied to such field operations as horizontal well drilling, well completing, oil recovery and gathering.

On March 20^th, the reporter knew from Coiled Tubing Sub-Forum of the 6^th International Petroleum Summit that the annual utilization ratio of domestic coiled tubing units has been got a significant increase, with localization of coiled tubing operation equipment and coiled tubes, with acceleration of domestic matching of crafts and tools, and with gradual solution of key restraint problems such as the safety & reliability and transportation. Coiled tubing has the prospect of becoming an “ultimate weapon” to modify the production mode of the oil-gas industry.

Modification of Oil-gas Production Mode Being to be Promoted

Coiled tubing can be applied to oil field drilling, well completing, fracturing and other fields. It has a wide sphere of application. More than 10 crafts can be applied for well workover only. During oil-gas production, coiled tubing and its operation equipment is called an “almighty operation machine”.

Compared with traditional operation mode, coiled tubing operation has a shorter operation cycle, lower accident rate and easier transportation. It can perform snubbing operation to protect oil-gas reservoir. It can facilitate operations of the horizontal well and the directional well. And it can carry out operation within tubing and operation through tubing.

Compared with traditional drilling mode, coiled tubing drilling has competitive advantages in improving drilling crafts, lowering costs (25%-40% fees to be saved) directional drilling and under-balanced drilling.

Since 1962 when the world first Coiled Tubing Unit (CTU) was born, this new operation unit has experienced a slow development in the initial years and a speeding development with multiplied quantities nowadays.

Statistics show that there were over 200 CTUs in the mid-1970s, 561 in 1993, around 850 in Feb. 2001, and more than 1000 in Jan. 2004.

Currently, the coiled tubing drilling has gained a mass application in oil-gas fields abroad. Especially now, slim-hole coiled tubing drilling, under-balanced coiled tubing drilling and directional drilling are giving their full play in development of shale gas and other unconventional natural gas.