WILCO ZAPP 2507
WILCO-ZAPP 2507 SDSS
WILCO ZAPP 2507 is a Super Duplex Stainless Steel (SDSS) that conforms to UNS S32750. The Super Duplex grades have excellent
properties for use as a slickline. They have high strength, good all-round corrosion resistance and excellent fatigue properties as
detailed below. All products are manufactured in ISO 9001 accredited factories and are weld free, 100% eddy current tested and
exceed the requirements of API 9A. The slicklines are supplied on painted reels and are protected for transport.
It should be noted that the information below is not exhaustive and other diameters can be considered together with alternative
material grades and lengths. Further information as to the application of all products is available on request
EBL is Effective Breaking Load is ABL - minus tool weight.
Corrosion Resistance
Both Duplex and Super Duplex stainless steels contain roughly equal amounts of austenite and ferrite and are known to possess the main characteristics of each phase without many of the limitations. This means that the alloys possess high strength, excellent fatigue resistance and good corrosion resistance and these properties make them ideal materials for slickline operation.
WILCO ZAPP 2507 is a Super Duplex SS available as a slickline and has outstanding strength coupled with excellent corrosion resistance to both chlorides and H2S when compared to alternative high alloy austenitic stainless steels.
One way of characterising corrosion resistance is PRENW, this is an empirical equation that relates those elements that are important in corrosion resistance allowing alloys to be compared.
In general, the higher the PRENW value then the better is the corrosion resistance. The most common form of the equation is shown below:
PRENW = Cr% + 3.3Mo% + 1.65W% + 16N%
WILCO ZAPP 2507 has a typical PRENW of 42.4
While Austenitic stainless steels resistance to chloride concentration decreases with temperature, Duplex stainless steels do not. Therefore, at higher
temperatures a Super Duplex SS may outperform a Super Austenitic stainless.
For sweet conditions, Super Duplex stainless steel slickline material has been successfully tested to 392°F and CO2 pressures to 100bar irrespective of chloride
concentration.
For sour service, guidelines for the selection of materials are detailed in the ISO 15156/NACE MR01/75 standard. The guide is based on PRENW number and any
Super Duplex SS whether UNS S32750 or UNS 32760 is within the category PRENW 40 to 45 and so both grades can be used under the same conditions, which
are 450°F, 3 psi H2S for any chloride level or pH in service.
However, the standard also states that if you have additional test information outside of this envelope then this can be used to justify selection of the material
type outside of these limits and within the boundaries of the test data produced.
The graph below shows additional test data available for Super Duplex stainless steel with a PRENW of 42 or greater from testing of actual Slickline product.
This test data allows the use of a Super Duplex Stainless Steel with a PRENW of 42 or greater within the envelope shown below.
This schematic shows that for 120000 ppm Chloride level, a super duplex can be used to 40 kPa (6 psi) of H2S, but if the chloride is less than 1000 ppm then it
will tolerate up to 80 kPa (12 psi) H2S. Wilco ZAPP 2507 SDSS can therefore be used over a wide range of conditions. Further information is available on request.
Most common alloy slickline materials have limited resistance to acidisation at temperatures witnessed downhole and corrosion resistance in HCl at
temperatures above 250°F is limited to a couple of special high performance alloys. High Alloy wires commonly used as slickline therefore rely heavily on
inhibitors. It is essential that an inhibitor is used that will protect the slickline, that the exposure is limited and the slickline is thoroughly washed after use.
Further information on the use of Wilco slicklines is available on request, Email: wilco@wilcowirelines.com
All possible care has been taken in the preparation of this document, but Wilco accepts no liability for any inaccuracies that may be found. Wilco reserves the right to make changes without notice both to this publication and to the product which it describes. All information in this sheet relates to Wilco products and do not necessarily apply to other grades.