Pore Volume Compressibility

Advanced Rock Properties – Pore Volume Compressibility

Pore Volume Compressibility: UPVC, HPVC and RTCM

Applications of PVC Data:

  • Drive mechanism determination
  • Recoverable reserves determination
  • Subsidence prediction
  • Reservoir compaction conditions
  • Horizontal permeability analysis

Advantages of UPVC:

  • Simulates actual reservoir production stress path
  • Accounts for inelastic behavior of reservoir rock
  • Measures compaction directly from axial strain
  • Obtains compressibility as a function of pore pressure
  • Differentiates horizontal from overburden pressure

 

Pore Volume Compressibility

Pore Volume Compressibility

 

Rate Type Compaction Method (RTCM)
Pore Volume Compressibility

First demonstrated by Waal and Smits in 1988, RTCM testing describes reservoir compaction non-linearity.

Hydrostatic Pore Volume Compressibility (HPVC)

HPVC Pros:

  • Simple, easy to perform
  • Quicker data at low cost

Pore Volume Compressibility
UPVC Apparatus

RTCM Forecast
Pore Volume Compressibility

Production rates change over the life of a field. Rate Type Compaction Method testing is used to obtain compaction as a function of production rates.

HPVC Cons:

  • Doesn’t simulate reservoir stresses
  • Indirectly estimates compressibility from the volume of expelled water
  • Assumes the sample is isotropic
  • Requires a Poisson’s ratio dependent correction to guess uniaxial values