Hi All!
I'm hoping someone can give me a bit of advice on an issue I've been working on while starting up a gas well that has been shut in for around 6 months. I'm a process engineer on a company graduate scheme, at the moment I'm working in operations and was asked an opinion at the weekend on a failed well startup.
The well being restarted is a wet gas well. The operators had been injecting methanol downhole (from a wellhead injection point) and when the choke was opened the well began flowing initially at 20 mmscfd, however the flow began tailing off and eventually stopped. Tophole pressure dropped as expected until it settled at the topside operating pressure. The bottomhole pressure fell as well, however it then plateaud and began slowly rising, this happened after the flow had tailed off. Once the choke was shut both the THP and BHP began rising before settling out. On two further restart attempts both pressure gauges showed the pressure initially drop, but again the gas flow was not sustainable.
My initial thoughts were that we had a liquid loading problem as opposed to a hydrate blockage, due to the movement in both BHP and THP during subsequent start up attempts. The SSSV was open prio to startup and I can't think where a hydrate would form. In addition the flow never stopped suddenly but began tailing off even while the BHP was still dropping. This is however the first time I've dealt with a problem like this and there is a suggestion that it is actually a hydrate blockage as opposed to liquid loading - which makes me think I've made a bit of an embarrassing mistake!
If anyone has any advice on what I should be looking for to prove/disporve liquid loading and/or a hydrate, or can share any similar experience I would appreciate it! I'm keen to learn from this.
Thanks!
I'm hoping someone can give me a bit of advice on an issue I've been working on while starting up a gas well that has been shut in for around 6 months. I'm a process engineer on a company graduate scheme, at the moment I'm working in operations and was asked an opinion at the weekend on a failed well startup.
The well being restarted is a wet gas well. The operators had been injecting methanol downhole (from a wellhead injection point) and when the choke was opened the well began flowing initially at 20 mmscfd, however the flow began tailing off and eventually stopped. Tophole pressure dropped as expected until it settled at the topside operating pressure. The bottomhole pressure fell as well, however it then plateaud and began slowly rising, this happened after the flow had tailed off. Once the choke was shut both the THP and BHP began rising before settling out. On two further restart attempts both pressure gauges showed the pressure initially drop, but again the gas flow was not sustainable.
My initial thoughts were that we had a liquid loading problem as opposed to a hydrate blockage, due to the movement in both BHP and THP during subsequent start up attempts. The SSSV was open prio to startup and I can't think where a hydrate would form. In addition the flow never stopped suddenly but began tailing off even while the BHP was still dropping. This is however the first time I've dealt with a problem like this and there is a suggestion that it is actually a hydrate blockage as opposed to liquid loading - which makes me think I've made a bit of an embarrassing mistake!
If anyone has any advice on what I should be looking for to prove/disporve liquid loading and/or a hydrate, or can share any similar experience I would appreciate it! I'm keen to learn from this.
Thanks!
