Jela123
Materials
- Feb 15, 2017
- 12
Hi guys. Need a bit of assistance on explanation for this. I am looking into the internal integrity preservation of future risers for a client.
The future risers were installed about 6-7 years and were pressure tested in-situ using freshwater to 230 barg. Documents at my disposal says that the risers were depressurized after the hydrostatic tests, anchor flanged at the topside and blind flanged subsea.
Recent pressure measurement on the risers showed internal pressure of between 0.8 - 2 barg. This was not expected since the risers contain only freshwater and was depressurized initially. Thinking that it was not properly depressurized 7 years by testing company, we depressurised it to zero barg but checks after a week interval showed the internal pressure to be back to 0.4 - 1.3 barg.
My question is where could the pressure build-up be coming from since both ends of the risers are flanged off?
The future risers were installed about 6-7 years and were pressure tested in-situ using freshwater to 230 barg. Documents at my disposal says that the risers were depressurized after the hydrostatic tests, anchor flanged at the topside and blind flanged subsea.
Recent pressure measurement on the risers showed internal pressure of between 0.8 - 2 barg. This was not expected since the risers contain only freshwater and was depressurized initially. Thinking that it was not properly depressurized 7 years by testing company, we depressurised it to zero barg but checks after a week interval showed the internal pressure to be back to 0.4 - 1.3 barg.
My question is where could the pressure build-up be coming from since both ends of the risers are flanged off?