Mechanical complex for reservoir protection
Wells with low reservoir pressure and high risk of heavy well-killing fluid loss during workover.
1 - Packer; 2 - Shut-off valve;
3 - On/off tool; 4 – Hollow rod;
5 - Check valve; 6 - Perforated fitting pipe;
7 - Pumping unit.
Mechanical complex is hermetically installed in a well dividing the pay zone and pumping equipment operation area. It has two operating positions. The first position allows to open the inner channel of shut-off valve during the liquid withdrawal period, thus the pump intake is communicated with the producing reservoir. In the second position the channel is closed during workover that makes possible to isolate the bottomhole zone from the contact with the kill fluid located above the shut-off valve.
1. Flexibility (the possibility of complex lowering with any standard downhole pumping equipment);
2. Possibility of bottomhole zone processing and control over the development of the producing reservoir in the sub-packer zone without the entire system removing with full preservation of sealing;
3. The pressure integrity both in the presence of a pressure gradient "top-down" and "bottom-up";
4. Availability of means to combat with debris and subsequent "sticking" of the package elements;
5. Convenience of installation (installation and dismantling of a shut-off valve for 1 trip with a standard tool of workover crews);
6. Significant time shortening for well commissioning.