In order to reduce costs and simplify surface configuration during conventional coiled tubing operations, we often use slimline wash tools for sand flushing, gas lift, and drag acidification. The outer diameter of slimline wash tools typically is same as internal connector, valve and washing tool that are connected with the coiled tubing.

Although we enjoy the simplified construction technology, we are often troubled because of accuracy of coiled tubing counter. When the coiled tubing string and tools are lifted out of the wellhead, manual closing of the wellhead valve several times is required to confirm position. If the tool is not fully removed from the well, there will be a damage of the valve and coiled tubing and tool caused by unclosing valve. Directly removed the coiled tubing and tool string out of spray box my cause blowout.

For the above situations, the coiled tubing end indicator was successfully introduced after a long time of exploration and development. The tool is installed in the wellhead valve, when the end of the coiled tubing string and tools pass through the indicator, its expansion link will remove according the situation of the coiled tubing string and tools. That allows the operator to visually locate the coiled tubing end for avoiding safety incidents. 

The indicator also has the following features:  

· When coiled tubing and tool string pass through the indicator, it can be visually displayed through the outside device.

· Balancing device is subjected to fluid pressure of external facilities, but not limited to the nagative influence of well pressure and can be used under 105MPa.

· Sensor can be installed out of CT operating room and data can be to display in the CT      operating room via photoelectric signal.