Mechanical Packer (with attached well screen) PZFM-140/146 - 2006
This mechanical packer design is intended to pack the annulus while equipping a well with a well screen attached to the bottom of it at the same time. Therefore a well screen is connected directly to the bottom end of this packer and a length of production tubing is connected directly to the bottom end of the well screen (so that it is sufficiently long enough to reach the bottom of the drilled well). Then the top end of this mechanical packer (PZFM-140/146 – 2006) is connected to the rest of the production tubing string above it. The whole tubing string assembly including the packer and the well screen will then be lowered into the production casing until the bottom of the production tubing string hits the bottom of the well and the packer and consequently the well screen and the packer are at the correct depth for the packer to be set. This packer is designed to for use with and to be connected to production tubing of 73mm (OD) and 89mm (OD of Tubing coupling).
Once the packer is at the intended depth, the packer setting is carried out by transferring the weight of the production tubing string above it through the bayonet joint to the expanding cone section of the packer ensuring seal deformation until contact with the inside wall of the ‘production casing string’ is made.
It should be noted as was indicated above, as the setting of the packer is done using the weight of the production tubing string, this type of packer is only used where the production tubing string continues beyond the bottom end of the well screen and goes some further distance down to the actual bottom of the drilled well (i.e. usually passed the pay-zone) where there is solid bottom to the well. This is because the bottom end of the whole production tubing string should be touching and resting on a solid surface at the bottom of the well before the weight of the tubing string above the packer can be transferred to the packer bayonet mechanism for it to set the packer.
This is in contrast to packers that are set using a rotational movement of the production tubing string in which case the production tubing string does not need to continue beyond the bottom of the well screen as the bottom of the production tubing string does not need to be sitting on a solid ground on the bottom of the well for the rotational movement of the tubing string to set the packer; it can happen as the packer and well screen are hanging from the production tubing string above them.
|Production casing diameter, mm||114; 140, 146; 168; 219|
|Production tubing diameter, mm||73, 89|
Screen base pipe diameter, mm
|Differential pressure, MPa||1,0|
|Outside diameter, mm||92; 114; 118; 140; 188|