In the wellbore, phase segregation and density changes become significant during gauge pressure measurements. Static pressure surveys capture this change in density, provided the gauge is stationed at different depths in the lower part of the tubing, where this change is most expected. These static pressures are then corrected to datum depth to determine the depletion across the field.

Conventionally, a one step pressure correction is used to correct the pressures from the gauge station to datum depth using the wellbore pressure gradient. This approach assumes that the same gradient exists, both in the reservoir and in the wellbore, which is generally not true in the case of gas condensate reservoirs, as well as oil & water producers.

This paper presents a two-step pressure correction workflow for gas condensate reservoirs.It proposes to establish a gradient from pressure measurements acquired from lower gauge stations, as segregated fluid density changes even in the liquid column. This is the wellbore gradient. It makes use of PVT parameters to determine the gradient developed by the reservoir fluid, which is independent of the wellbore gradient, to ensure that the correction to datum depth incorporates the actual reservoir conditions.

It was observed that two step correction, which makes use of reservoir fluid gradient in 2nd step, provides pressure values comparable with formation testing results in contrast to single step corrected pressures. This paper presents a step by step workflow and emphasizes how important it is to make use of actual reservoir conditions while correcting pressure measurements. Advantages and disadvantages of each correction method are also discussed

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