Page 84: of Offshore Engineer Magazine (Sep/Oct 2013)

83 85

Production

Depth control:

A coil tubing reel in action.

in real time wheel in contact with the pipe, which (5/16-in. or 7/16-in.) inside the CT.

Issues can develop in a effectively measures the length of pipe This system of “stiff wire” logging has producing well that can that has passed. several drawbacks: it limits the fuid negatively affect operations,

The main discrepancy in this system rates and types of fuids that can be comes from slippage of the wheel pumped, it does not allow balls to be production, and ultimately, against the surface of the pipe, due to a pumped to activate ball drop tools and revenue generated. Oilfeld build-up of rust, wax, oil or other sub- adds a signifcant amount of weight to services provider Aker Solutions stances. In addition, it cannot take into the coiled tubing reel when installed.

account downhole stretch of the CT Aker Solutions designed and devel- has recently completed trials of itself, which can vary on each job due oped a real time coil (RTC) system a new well intervention system to temperature, pressure, or deviation. with a view to overcoming the prob- designed to track coiled tubing

Depth control is more critical during lems associated with the traditional complex well intervention operations, method. It captures all of the necessary operations in real time. so it is important that accurate mea- downhole data and transmits it in real

Donald Kellock explains. surements can be taken to determine time back to the coiled tubing cabin. the position of the bottom-hole assem- This is all achieved by using a 1/8-in.- lthough technology has bly (BHA) in the well. diameter wire inside the CT. advanced in recent years, the Logging a well or correlating depth main method of determin- on CT in real time is not a new innova-

A System overview ing depth during coiled tubing (CT) tion. It has traditionally been carried The RTC system consists of three main operations still relies on a mechanical out using a standard e-line cable components: the downhole BHA/

OE | September 2013 oedigital.com 86 086_OE0913_ProdOps4_CT_Aker.indd 86 8/18/13 8:40 PM