InSitu Density Reservoir Fluid Density | SLB

InSitu Density

Reservoir fluid density and viscosity sensor

Representation of fluid sampling at the reservoir
Representation of fluid sampling at the reservoir

Directly measure formation fluid density and viscosity at reservoir conditions

The InSitu Density reservoir fluid density and viscosity sensor directly measures formation fluid density and viscosity in real time, downhole, at reservoir conditions. No calibration for pressure and temperature is required. This accurate, immediate measurement provides numerous advantages over surface measurements, especially for determining pressure gradients in thin beds or carbonate transition zones and identifying fluid contacts.

The quantified variation of fluid density as a function of depth—instead of having to rely on a linear approximation—readily identifies both compositional grading within a fluid column and whether compartmentalization is affecting zonal connectivity.

The viscosity of reservoir fluid is similarly important because it directly governs reservoir deliverability, injection, sweep efficiency, and enhanced oil recovery (EOR) performance.

350-degF temperature rating
25,000-psi pressure rating
NACE MR0175 compliance
InSitu Density sensor graph
The dual-measurement modes of the InSitu Density sensor directly measure both density and viscosity.
InSitu Density sensor graph

How it works

The miniaturized InSitu Density sensor fits the sensor slots of the InSitu Fluid Analyzer real-time DFA system to provide density measurements in a range of 0.5 to 1.2 g/cm3 and viscosity measurements in a range of 0.2 to 50 cP.

The sensor’s dual-resonance modes enable measurement at a 1-s frequency. The resonance frequency is related to the density of the flowing fluid, and the resonance damping is related to the viscosity. The characterization parameters incorporated in the sensor’s integrated electronics enable assessing measurement quality in real time to ensure that the response spectrum is within specification.

The viscosity measurement is for miscible systems (oil sampling in oil-based mud). In higher-viscosity fluids or reservoir fluids with up to 10% water, the InSitu Viscosity reservoir fluid viscosity sensor is used with the InSitu Fluid Analyzer system, with the required density input for the viscosity measurement provided by the InSitu Density sensor.