I2P
Chemical
- Jan 20, 2003
- 38
Friends,
I work in a gas processing plant. We recently have encountered a hydrate formation in one of our subsea pipelines. Though a lot of study was made on hydrate prevention, and the requisite KHI dosing was commenced as per guidelines l;aid down, we still had a hydrate problem, whcih could only be cleared after MEG injection.The gas is sour, and wet. We had clear guideliens at what temperatures to inject Kinetic hydrate inhibitor and at what temperatures to inject MEG. Intially KHI was injected, and with further lowering of temperatures MEG was injected. The KHI was continued and MEG was stopped. After stoppage of MEG within 10 hrs hydrate plugging happened.The lab results had validated effectiveness of the selected KHi for hydrate inhibition.Since the hydrate formation happened despite this, I am interested in knowing what could have gone wrong? My doubts are as under:
1.0 Was the hydrate temp prediction erratic? How much does the hydrate temp change in presence of H2S and without H2S?
2.0 Is there any empirical correlation available which uses the pipelien pressures to estimate hydrate forming temperatures?
3.0 If these temp were a result of simulation and lab studies on KHI, what would have been the error in not feeding the correct avg gas composition?
Top those of you who might need any further data I am most willing.
I work in a gas processing plant. We recently have encountered a hydrate formation in one of our subsea pipelines. Though a lot of study was made on hydrate prevention, and the requisite KHI dosing was commenced as per guidelines l;aid down, we still had a hydrate problem, whcih could only be cleared after MEG injection.The gas is sour, and wet. We had clear guideliens at what temperatures to inject Kinetic hydrate inhibitor and at what temperatures to inject MEG. Intially KHI was injected, and with further lowering of temperatures MEG was injected. The KHI was continued and MEG was stopped. After stoppage of MEG within 10 hrs hydrate plugging happened.The lab results had validated effectiveness of the selected KHi for hydrate inhibition.Since the hydrate formation happened despite this, I am interested in knowing what could have gone wrong? My doubts are as under:
1.0 Was the hydrate temp prediction erratic? How much does the hydrate temp change in presence of H2S and without H2S?
2.0 Is there any empirical correlation available which uses the pipelien pressures to estimate hydrate forming temperatures?
3.0 If these temp were a result of simulation and lab studies on KHI, what would have been the error in not feeding the correct avg gas composition?
Top those of you who might need any further data I am most willing.
