JOULE-THOMSON EXPANSION OF HIGH-PRESSURE-HIGH-TEMPERATURE GAS-CONDENSATES

This paper presents calculations of Joule-Thomson inversion effects in high-pressure-high-temperature gas condensates. Isenthalpic expansion s were modelled for several gas condensate mixtures reported in litera ture using the Soave-Redlich-Kwong and the Peng-Robinson equations of state. The calculations confirmed qualitatively the heating of gas con densates at expansion. Although reservoir temperatures are in the regi on where cooling occurs, i.e., inside the inversion curve, it was show n that reservoir pressures lie outside this region, and that the tempe rature will increase until the inversion curve is reached. The calcula ted temperature increases are not very large. Although exact values de pend on fluid composition, reservoir conditions, and pressure drop, ty pical calculated temperature increases are in the range of 10-30 degre es C for reservoir pressures of 1000 bar. A sensitivity study showed t hat both reservoir pressure and fluid composition greatly affect the t emperature increase. With increasing pressures and increasing amounts of heavy constituents present in gas condensate mixtures, the maximum possible temperature effect will also increase. Unfortunately, due to lack of experimental information, the calculated results could not be verified on their reliability. (C) 1997 Elsevier Science B.V.