Blast joint placement criteria

10 January 2020 We are planning workover for the existing multiple zone gas well with dual strings. 
The plan is to develop a new lower zone and complete it and existing upper zone with dual strings (13Cr).   
According to the rule of thumb, we should put blast joints in long string (highlighted in red in attached file) to cover the upper zone completion section.

However, we are not sure we should do that with considering the short field life like ~6yrs and the low productivity of the upper zone which is known like ~50k Sm3/d. 
We doubt such a gas rate would erode the 13Cr material severely and would like to use normal 13Cr tubing instead from the economical point of view if feasible.

Q1. Is there any criteria to define if we should apply the blast joint (production rate, tubing material, size,..)?

Q2. Is there any criteria how long additional length of the blast joint should we put against the completion zone?

Please help...thank you very much!

Documents uploaded by user:

Well schematic.PNG

6 Answer(s)

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