API N80(1) vs L80(1) 1

[dursosono]

In which case I have to used API 5CT N80(1) or L80(1) for production well? Can anyone describe the adventage of both material? I have reviewed both, but they are look like no significant differents. Thank for the advice

 

[redpicker]

There is a lot of overlap in the grades. The big difference is that N80 may be normalized, normalized and tempered, or quenched and tempered where L80 must be quench and tempered. Since it is quenched and tempered, L80 can be suitable for some sour environments, particularly if the hardness is kept below 23 HRC. Because of the higher yield to tensile ratio in the Q & T condition, the tensile strength of L80 is dropped a little compared to N80.

Historically, N80 was introduced first. Some users preferred the quenched and tempered version. They didn't want to change the grade to require Q & T since the normalized product was popular (and a lower cost), so they introduced the L80 grade.

Since most performance calculations are based on minimum yield, they can often be interchanged. Many high-end users will require L80 only, however.

rp

 

[dursosono]

How much psia max limit value of H2S partial pressure may accepted for these materials?

 

[salmon2]

I guess none of L80 or N80 is suitable for H2S environment. redpicker had given an excellent summary about two types of material and this is good refreshment for me too.

 

[mattweb]

As per NACE MR0175/ISO 15156, both grades are acceptable for any partial pressure of H2S. The only restriction (as per Part 2, Table A.3) is that N80 can only be used at temperatures less than 225°F. L80 can be used at all temperatures. Note that L80 refers to L80 Type 1. Also, as with other carbon & low alloy steels mentioned in the NACE standard the maximum allowable hardness is 22 HRC.

 

[SandManner]

I have a well completion coming up that has a 4% saturation of CO2 and 1 ppm H2S. We are trying to decide the most cost effective material to use for the completion components. The temperature is approximately 130deg F. with multi phase oil, gas, and salt water production.

I would be grateful for all help.
Sandy Manner

 

[nottoobright]

I have a question not related to this post that perhaps some of you can help me with.
How can I calculate the tensile strength and collapse strength of the following?:

13 3/8" API casing, 54.5 PPF, K-55, Range 3, perforated on 16% of it's surface area with uniformly spaced 5/8" holes.

 

[salmon2]

nottoobright,

K-55 directly tells you the yield stength. For collapse pressure, it is a bit tricky, you can look up API 5C3.

salmon2