The Controlled Debris Removal System (CDRS) gives the operator the ability to safely remove debris from wells with low formation pressures by reverse circulating debris using coiled tubing.
The system comprises of two key components; the Selective Dual-Flapper Check Valves and a Flow Control Valve.
The Selective Dual-Flapper Check Valves allow the operator to lock ‘open’ the Check Valves using a low pressure (approx. 500 PSI). Running in hole the Check Valves will be in the conventional ‘closed’ position. Locking the Check Valves open (The Check Valves will remain open for as long as required until the cleaning operation is completed), enables debris to be reverse circulated into the Coiled Tubing, then using pressure again the Check Valves can be cycled back to the normal running position (closed) prior to pulling out of hole.
The Flow Control Valve is a 2-way valve which opens at a pre-determined pressure (adjustable 1000 – 4500 PSI) to allow flow from the BHA into the wellbore or free flow from the wellbore into the Coiled Tubing when the Check Valves are locked open. The purpose of the Flow Control Valve is two-fold; it allows the Check Valves to be cycled open or closed without pumping any fluid into the well and the system can also be used as a Bailer Tool with the Coiled Tubing itself, ensuring the debris is retained within the coil.
The system is available in a variety of sizes and configurations to suit each application.