TY - JOUR
T1 - Hydrate Equilibrium Data of Multicomponent Systems in the Presence of Structure-II and Structure-H Heavy Hydrate Formers
AU - Ostergaard, Kasper Korsholm
AU - Tohidi, Bahman
AU - Burgass, Rod W.
AU - Danesh, Ali
AU - Todd, Adrian C.
PY - 2001/5/1
Y1 - 2001/5/1
N2 - The effect of six newly discovered heavy hydrate-forming compounds on the hydrate phase boundary of a gas mixture, a natural gas, and a model oil has been measured. The study, which is a continuation of a previous work,1 investigates the effect of cyclopentane, cyclohexane, neopentane, isopentane, methylcyclopentane, and methylcyclohexane at various concentrations. The first three compounds form structure-II hydrates, while the last three compounds are known to promote structure-H hydrates. The experimental hydrate dissociation data have been successfully predicted by the use of a thermodynamic model. The results show that structure-II is the stable hydrate structure for the systems investigated at various heavy hydrate former concentrations (from 0.27 mol % to 59.66 mol %). Also, the structure-II heavy hydrate formers promoted structure-II hydrate formation whereas the structure-H heavy hydrate formers (at the concentrations used) did not change the stable hydrate structure to structure-H and hence inhibited hydrate formation in the above fluid systems. On the basis of the above study, it was concluded that the inclusion of structure-II heavy hydrate formers in the thermodynamic modeling would improve the reliability of hydrate-free zone predictions in real reservoir fluids.
AB - The effect of six newly discovered heavy hydrate-forming compounds on the hydrate phase boundary of a gas mixture, a natural gas, and a model oil has been measured. The study, which is a continuation of a previous work,1 investigates the effect of cyclopentane, cyclohexane, neopentane, isopentane, methylcyclopentane, and methylcyclohexane at various concentrations. The first three compounds form structure-II hydrates, while the last three compounds are known to promote structure-H hydrates. The experimental hydrate dissociation data have been successfully predicted by the use of a thermodynamic model. The results show that structure-II is the stable hydrate structure for the systems investigated at various heavy hydrate former concentrations (from 0.27 mol % to 59.66 mol %). Also, the structure-II heavy hydrate formers promoted structure-II hydrate formation whereas the structure-H heavy hydrate formers (at the concentrations used) did not change the stable hydrate structure to structure-H and hence inhibited hydrate formation in the above fluid systems. On the basis of the above study, it was concluded that the inclusion of structure-II heavy hydrate formers in the thermodynamic modeling would improve the reliability of hydrate-free zone predictions in real reservoir fluids.
UR - http://www.scopus.com/inward/record.url?scp=0035335814&partnerID=8YFLogxK
U2 - 10.1021/je0003086
DO - 10.1021/je0003086
M3 - Article
SN - 0021-9568
VL - 46
SP - 703
EP - 708
JO - Journal of Chemical and Engineering Data
JF - Journal of Chemical and Engineering Data
IS - 3
ER -