dcharl9
Petroleum
- Oct 8, 2015
- 1
I just got a job with a coiled tubing company and I am reviewing some old data.
JOB: There was work on a 15000' gas well that had formation pressure of 9.3 ppg. SITP was 5000, and we displaced the well with 8.6 ppg FSW. After we displaced the fluid in the well, I saw that the WHP came down to 1000 psi. About 400 psi more than I expected. I also saw that WHP fluctuated between 2000-4000 psi through the job (keeping bbl in and bbl out - so claim the crew).
So my one of my two question is this. What would cause WHP to do this? My hypothesis is that the well was actually stronger than 9.3 ppg EMW and whenever we replaced the well with 8.6 ppg fluid and a WHP of 1000 psi we were actually still taking on gas. So it was as if throughout the job we were letting the well consistently unload our column of fluid as we tripped into and out of it.
Also, I saw the pump rate was all over the place. The pump operator wasn't maintaining the requested 1 BPM fluid rate (usually done when the choke operator manipulates his/her choke). Could this contribute to the WHP issue? Would not maintaining the 1 BPM significantly change the system outside of the annular velocities? I know if would change frictional pressure losses but is that loss covered by the 'gain/loss' in WHP?
Thanks in advance! I know it's lengthy. If you could also give your suggestion on any great well control literature that would be great.
JOB: There was work on a 15000' gas well that had formation pressure of 9.3 ppg. SITP was 5000, and we displaced the well with 8.6 ppg FSW. After we displaced the fluid in the well, I saw that the WHP came down to 1000 psi. About 400 psi more than I expected. I also saw that WHP fluctuated between 2000-4000 psi through the job (keeping bbl in and bbl out - so claim the crew).
So my one of my two question is this. What would cause WHP to do this? My hypothesis is that the well was actually stronger than 9.3 ppg EMW and whenever we replaced the well with 8.6 ppg fluid and a WHP of 1000 psi we were actually still taking on gas. So it was as if throughout the job we were letting the well consistently unload our column of fluid as we tripped into and out of it.
Also, I saw the pump rate was all over the place. The pump operator wasn't maintaining the requested 1 BPM fluid rate (usually done when the choke operator manipulates his/her choke). Could this contribute to the WHP issue? Would not maintaining the 1 BPM significantly change the system outside of the annular velocities? I know if would change frictional pressure losses but is that loss covered by the 'gain/loss' in WHP?
Thanks in advance! I know it's lengthy. If you could also give your suggestion on any great well control literature that would be great.
