The invention of a completely new device to rotate CT was driven by the numerous advantages that such a capability would provide. This new concept, called the Tubing Intervention Manipulator, will extend coiled tubing to a wider variety of uses, save time and reduce costs.


The spool is a canister design with modular capabilities. The CT can be rotated in any direction or held still. The CT can be rotated while going into or out of the well, facilitating many different applications such as boring, pipeline work, steam flood, various cleanout applications and all types of drilling applications.

A working model is rigged up on a well in Louisiana. (Photos courtesy of Rental and Fishing Tools Inc.)


The ability to either rotate or immobilize the CT allows for complete operational control of the well. It reduces friction in mud motor drilling applications. Rotation can help considerably with lateral drilling applications, as well as facilitate back-washing debris in the hole. Getting stuck is virtually eliminated, because of the ability to rotate the coiled tubing in any direction while spooling in or out simultaneously.


The spool (canister) can be oriented in a vertical position directly over the well bore, in a horizontal position adjacent to the well bore or any other useful angle useful. This concept greatly expands current limitations in conventional CT applications. Transportability is greatly improved, including a smaller foot print on the well site. The canister may be open, with access ports for inspection, or completely enclosed for environmental safety.


When mounted directly over a well bore, there is considerably less bending of the CT, because there is no need for a gooseneck. It is estimated that the life of each CT string will be extended by at least five to seven times compared to conventional gooseneck injection techniques. This will equate to significant cost savings in CT replacement schedules. It will also allow for more aggressive and creative applications.


The ability to rotate the CT should also enhance downhole mud-motor performance. This concept provides superior multilevel capabilities. It has the ability to rotate and set packers or downhole tools, the ability to backoff, and it has agility in directional drilling and fishing operations.


The unit will require a smaller crew to operate than most other intervention methods. The canister can totally enclose the CT for pressure safety and to contain leaks or spills.


How it works


The Tubing Intervention Manipulator is operated from a center axis that is connected to an injector or feeder head. The injector feeds the CT simultaneously in or out of the canister through a swivel or helix pattern controlled by a lead screw or indexing device. The CT is stored inside the spool rather than on the outside of the spool as in conventional CT applications. This spooling method is considered the most natural to the CT and will allow for much longer use of the CT compared to conventional applications.


Rotating allows greater ease of movement in lateral drilling operations, helps to move debris out of the way and thus facilitates a much smoother and efficient lateral directional move in the well bore. The ability to rotate the CT in either direction greatly reduces the chance of sticking. The invention will certainly save time and reduce costs, which can change the economics of oil and gas fields that are now commercially marginal.

The model has 3/4-in. coiled tubing on the spool.


According to one CT manufacturer, the invention will stimulate further research and development of CT. Because of the cost savings potential from less wear, new types of CT may be economically feasible, facilitating greater use of CT in more applications. For example, there has been interest among several independent oil companies in using this technology to deepen wells.



Questions and answers



  • How strong is the CT? It is almost twice the torque of shoulder-connection type tubing.

  • Will the CT be like spaghetti in the hole? No. It goes through a pipe straightener first and will remain straight in the hole. The properties of CT will cause this to take place.

  • Will the coil wear more or less in this process? An expert at a major CT manufacturer estimates that the CT will last approximately five to seven times longer than in conventional use. There are a number of bends eliminated by our process, and the bending radius is the most natural bending of the CT. This facilitates longer life.

  • How large will the spool be for 10,000 ft (3,048 m) of CT? It will be comparable to current conventional spools. Length versus width will offer benefits. The spool can be longer our way. CT spools can be componentized. So you could bring a very large amount of CT to a location as well as different sizes of CT.

  • What about the weight of the CT overhead? No one will be working underneath the CT, but the same amount of tubing racked in a derrick is heavy as well.

  • How do you circulate? You circulate through swivel at the top of the spool, similar to current methods.

  • How fast can you rotate? RPM will vary depending on various applications. Remember that mud motors will continue to be used. Rotation will be controlled hydraulically. Braking of spool rotation will be controlled hydraulically, and a braking device may also be incorporated in the system because of the weight of the spool.


The working model, with ¾-in. CT on the spool, is currently rigged up on a well in Louisiana. The model has been demonstrated to a number of oil companies and CT service companies. The Mechanical Engineering Department at Texas A&M University has taken on the project as a Capstone Design Project. The goal is to design a commercial unit that will work both onshore and subsea.


The Tubing Intervention Manipulator, with its unique ability to rotate and immobilize CT, will benefit the industry in numerous and significant ways. The biggest limitation of CT in many oilfield operations — its inability to rotate — has now been overcome.