Nandesh Kumar
Not enough information and I am not an interpreter.
But if the documents are saying when to do CTOD tests?
Then "For offshore pipelines" stands alone.
then it says and "for" other pipelines where required by the project specification CTOD using SENT required
these are two instances where CTOD tests are required, For offshore pipelines and when called for in the project specifications.
Crack Tip Opening Displacement is not something that I was familiar with until this post, Thanks for the question.
Just my opinion. Good Luck
Marshall

First you have to know what the test are and how they relate. What your client is telling you is that if you utilize CTOD (Crack tip opening displacement) for determining your J integral or J-resistance curves for determining critical defect size I.E. ECA (Engeering Critical Assessment), then you must also use Sent (single edge notch tension) testing to provide accurate numbers rather than deriving your numbers from a simple bend test.

I am surprised your client is allowing the contractor to do that part, but stranger things have happened.

Regards,
Gerald

Nandesh - does your last post mean you now know the answer - yes it is required? If not, how about submitting a Technical Query to the design authority for the definitive answer.