Annulus Zonal isolation Packer
Saltel XPandable Steel AZIP (Annular Zonal Isolation Packer) uses proprietary expandable stainless steel technology and a patented thin layer of bonded elastomer to achieve zonal isolation.
The elastomer is used together with expandable dynamic seals for temperatures above 250 degF.
AZIP Packer activation procedure
The AZIP comes onto the casing string ready to run in open or cased hole. Once at depth, you apply pressure by pumping from the surface to expand the packer. You can seal the lower end of the casing with a plug and then pressurize the full string above. Alternatively, you can pressure up through the expansion port, with a cup tool or a PBR.
While pumping, you will transmit the pressure through the expansion port to the packer’s integral stainless steel sleeve. The sleeve expands into the annulus between the casing and borehole or outer casing string. Similarly, the AZIP conforms to the real shape of the wellbore and seals the annulus. Note that the sleeve expansion will also centralize the casing string.
Different models of the AZIP Packer are available to optimize for a range of applications.
AZIP Packer setting process
AZIP Packer applications
AZIP models
0-0 AZIP
The expansion port features a valve system integrated within the casing thickness and serves as a safety feature. In case the packer sets in front of a severe washout, the valve closes and prevents fluid loss.
1-0 / 0-1 AZIP
1-0 or 0-1 AZIP features an expansion and pressure compensation valve at the top (1-0) or bottom (0-1). This valve permanently closes the expansion port and establishes casing integrity once the packer sets and reaches a predetermined pressure. This activation pressure is adjustable by replacing an easily accessible shear pin. The valve also acts as a safety feature in the event of washouts.
Closing the expansion port establishes fluid communication and pressure balance between the annulus at the packer’s valve end and the space inside the expanded steel sleeve. Balancing these pressures enables the packer to overcome higher annulus pressures at that end, giving high sealing capability and excellent resistance to thermal cycling. The appropriate AZIP model will depend on whether there is high pressure above or below the packer.
1-1 AZIP
The elastomer skin teams up with expandable dynamic seals for temperatures above 250 degF [121 degC]. The 1-1 AZIP comes with a pressure compensation valve at each extremity of the packer to balance the packer’s internal pressure with the highest annular pressure.
The 1-1 AZIP maintains sealing performance in all well conditions during injection, production, and stimulation. The dual-pressure compensation valve manages annular pressure over the well’s life, regardless of whether the highest pressure is above or below the packer. The packer seals effectively in wells with oval (up to 10% ovalization), out-of-gauge, and irregular boreholes, and even through thermal cycling.
Casing-while-drilling (CWD) AZIP
Available for 13 3/8-in casings, the AZIP CWD model has a fit for basin design to resist aggressive conditions experienced during specialty drilling applications, such as with the Allegro CD directional casing-while-drilling service. Its annular sealing capacity for cement support and backup applications matches that of the other AZIP models while adding increased resistance to torque, shocks, and abrasion during casing drilling. The packer’s steel sleeve expands between the casing and the borehole by applying pressure in the casing until it conforms to the wellbore shape. Sealing with an uneven borehole surface is achieved through a thin layer of bonded elastomer.
