Abstract

Naturally fractured reservoirs (NFR) represent an important percentage of worldwide hydrocarbon reserves and production. The performance of naturally fractured gas condensate reservoirs would be more complicated regarding both rock and fluid effects. In contrast to the dual-porosity model, dual-porosity/dual-permeability (dual-permeability) model is considered as a modified model, in which flow to the wellbore occurs through both matrix and fracture systems. Fluid flow in gas condensate reservoirs usually demonstrates intricate flow behavior when the flowing bottom-hole pressure falls below the dew point. Accordingly, different regions with different characteristics are formed within the reservoir. These regions can be recognized by pressure transient analysis. Consequently, distinguishing between reservoir effects and fluid effects is challenging in these specific reservoirs and needs numerical simulation. The main objective of this paper is to examine the effect of condensate banking on the pressure behavior of lean and rich gas condensate NFRs through a simulation approach. Subsequently, evaluation of early-time characteristics of the pressure transient data is provided through a single well compositional simulation model. Then, drawdown, buildup, and multirate tests are conducted to establish the condition in which the flowing bottom-hole pressure drops below the dew point causing retrograde condensation. The simulation results are confirmed through well test analysis in both Iranian naturally fractured rich and lean gas condensate fields. Interpretations of simulation analysis revealed that the richer gas is more prone to condensation. When the pressure drops below the dew point, the pressure derivative curves in the rich gas system encounter a more shift to the right, and the trough becomes more pronounced as compared to the lean one.

Highlights

  • Fractures may have the adverse effect on reservoir productivity and cause earlier unwanted water production, erratic sweep patterns, and low recovery factor [9,10,11]. is issue is more critical in naturally fracture water drive gas reservoirs. is water expansion in naturally fractured reservoirs, with low matrix permeability, fills up the fractures, and the free gas will stop flowing. us, water would be the only fluid passing through the fractures, and early breakthrough happens [12]

  • Derivative curves indicate that, below the dew point, reduced mobility region is formed near the wellbore. is behavior occurs after an upward shift in the early time derivative stabilization

  • More liquid saturation is formed in the case of the rich gas condensate system compared to the lean one, there is no sharp difference k[m d]

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Summary

Research Article

Numerical Well Test Analysis of Condensate Dropout Effects in Dual-Permeability Model of Naturally Fractured Gas Condensate Reservoirs: Case Studies in the South of Iran. E performance of naturally fractured gas condensate reservoirs would be more complicated regarding both rock and fluid effects. Fluid flow in gas condensate reservoirs usually demonstrates intricate flow behavior when the flowing bottom-hole pressure falls below the dew point. E main objective of this paper is to examine the effect of condensate banking on the pressure behavior of lean and rich gas condensate NFRs through a simulation approach. En, drawdown, buildup, and multirate tests are conducted to establish the condition in which the flowing bottom-hole pressure drops below the dew point causing retrograde condensation. E simulation results are confirmed through well test analysis in both Iranian naturally fractured rich and lean gas condensate fields. When the pressure drops below the dew point, the pressure derivative curves in the rich gas system encounter a more shift to the right, and the trough becomes more pronounced as compared to the lean one

Introduction
Transition radial flow stabilization
Gas Condensate
Initial saturation
Discussion
Rock properties
Findings
Below dew point
Full Text
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