Professionals of TatNIPIneft have developed an installation for dual production in small diameter wells. The unit is designed for dual completion of targets (formations) in the wells with a nominal production string diameter of 114 mm (4-1/2”). Dual production technology was earlier applied in wells with 146 mm (5-3/4”) and 168 mm (6-5/8”) production strings.

The need for single-lift dual completions is due to the fact that technologies of drilling small diameter wells are being successfully implemented at JSC TATNEFT. 235 wells of this kind have been drilled by the Company as of the beginning of 2013. There are multiple productive formations in many of them.

The unit has been designed for dual completion of two packer separated targets (formations) with their optimal operating parameters, and provides for zonal isolation, lifting and allocation metering, as well as the achievement of design development rates.

As in the case of conventional single-lift installation, when the bottomhole pressure of the upper target is higher than the pressure of the lower one, the products from the target with the lower bottomhole pressure enter the pump cylinder through the main pump suction valve, and the ones from the upper target - through the additional valve set below the pump cylinder.

If the bottomhole pressure at the pump is higher at the lower target level, then the additional valve installed below the pump is connected to the under-the-packer area, while the main valve opening is connected to the annulus.

The first dual completion technology for small diameter wells was introduced in mid-December of 2012 at NGDU Yamashneft. Pilot testing of such technology is now planned for six wells operated by three different Tatneft’s Oil and Gas Production Boards.