Identification of thermal conductivity properties of formation fluid

A downhole fluid sensing device for determining heat capacity of a formation fluid produced by a sampled subterranean well, the device comprising:

• an annulus shaped elongated sensor package body interiorly defining a substantially cylindrical fluid sampling space, the elongated sensor package body and the sampling space having a common longitudinal center axis;
• a fluid entrance port providing a well fluid ingress into the fluid sampling space;
• a fluid exit port providing a well fluid egress out of the fluid sampling space;
• an upstream-to-downstream fluid flow path for a sampled well fluid extending from the fluid entrance port to the fluid exit port across the sampling space;
• a heat source coupled to the elongated sensor package body and located is centrally positioned longitudinally within the sample space on a longitudinal center axis between the fluid entrance port and the fluid exit port for inputting heat into the sampled well fluid;
• and
• a plurality of temperature sensing devices coupled to the elongated sensor package body and located between the fluid entrance port and fluid exit port for measuring heat conducted to the sampled well fluid, wherein each of the plurality of temperature sensing devices is radially spaced from the heat source and wherein the measurement is used to calculate the heat capacity of the formation fluid, wherein the heat source is centrally positioned longitudinally within the sample space on the longitudinal center axis.

A method for determining thermal conductivity of a formation fluid produced by a sampled subterranean well, the method comprising:

• receiving, through a fluid entrance port, formation fluid flow in an annulus shaped, elongate body interiorly defining a substantially cylindrical fluid sampling space, the elongate body and the sampling space having a common longitudinal center axis;
• applying thermal energy to the fluid sampling space, wherein the thermal energy is applied by a heat source coupled to the elongate body and located circumferentially around at least a portion of the fluid sampling space;
• measuring a temperature change over time at a plurality of temperature sensing devices concentrically coupled to the elongate body, wherein the plurality of temperature sensing devices are longitudinally spaced along the sampling space and radially separated from the heat source;
• and
• calculating the effective thermal conductivity of the formation fluid based on the temperature change profile and transient temperature response decay slope.

A method for determining thermal conductivity of a formation fluid produced by a sampled subterranean well, the method comprising:

• receiving, through a fluid entrance port, formation fluid flow in an annulus shaped, elongate body interiorly defining a substantially cylindrical fluid sampling space, the elongate body and the sampling space having a common longitudinal center axis;
• applying thermal energy to the fluid sampling space, wherein the thermal energy is applied by a heat source, the heat source centrally positioned within the sampling space on the longitudinal axis;
• measuring a temperature change over time at a plurality of temperature sensing devices concentrically coupled to the elongate body, wherein the plurality of temperature sensing devices are longitudinally spaced along the sampling space and radially separated from the heat source;
• and
• calculating the effective thermal conductivity of the formation fluid based on the temperature change profile and transient temperature response decay slope.