Impact of Retrograde Condensation on Production in the Ohio Utica Point Pleasant.

摘要

The purpose of this thesis was to study the sensitivity of production in the Ohio Utica Point Pleasant play to retrograde condensation. To accomplish this two fluid models were created for a rich and lean gas condensate and two base models were created to reflect the anticipated geologies where these reservoir fluids will be encountered. A single hydraulically fractured horizontal well was placed in both models. Experimental parameters of well length, stage spacing, hydraulic fracture properties, bottom hole pressure (BHP) controls, and fluid models adjusted for pore confinement effects were varied and tested over a series of simulations. The Peng-Robinson Equation of State model was used to model the phase behavior of the fluids within the reservoir. After all simulations were completed the results were analyzed to investigate how the parameters and resulting condensation affected the well's performance.;Longer lateral lengths resulted in greater production due to maximizing reservoir contact, but did not curtail retrograde condensation. Earlier fluid drop out was observed with closer stage spacing schemes due to higher drawdown, but condensate saturation in the reservoir was also lessened as a result. Less condensate was trapped and more was produced. The lowest BHP controls enhanced gas recoveries, but BHP settings close to fluid dew points optimized condensate recovery. Fractures with infinite conductivity offered dramatically improved gas production compared to those with finite conductivity. However, infinite conductivity also yielded lower condensate production because of greater impairment from condensate blockage. Accounting for a hypothetical shift in fluid critical properties due to nanopore confinement reduced the condensate saturation in the reservoir and maximized gas and oil production for the lean fluid type, but caused mixed results for the rich fluid type.