High temperature fluid test instrument

A system for determining the water wettability of a mixture under downhole conditions, the system comprising:

• a first cell adapted to contain a fluid, the first cell including a first piston adapted to apply pressure to a first fluid contained within the first cell, a first paddle, a first conductivity probe, and a first heater;
• a second cell adapted to contain a fluid, the second cell including a second piston adapted to apply pressure to a second fluid contained within the second cell, a second paddle, a second conductivity probe, and a second heater;
• a first valve in fluid communication with the first fluid of the first cell and in fluid communication with the second fluid of the second cell, wherein a portion of the first fluid may be transferred from the first cell into the second cell;
• a flow meter, the flow meter measures the portion of the first fluid transferred into the second cell;
• and
• a wettability readout, the wettability readout electrically connected to the first conductivity probe and electrically connected to the second conductivity probe.

An apparatus for determining the water wettability of a fluid under downhole conditions, the apparatus comprising:

• a cell adapted to contain a fluid;
• means for applying pressure to a fluid contained within the cell;
• means for mixing the fluid;
• means for heating the fluid in the cell;
• and
• means for determining the water wettability of the fluid, wherein the means for mixing the fluid may further comprise means for exerting a known shear rate on the fluid.

A method of determining the wettability of a mixture of a spacer fluid and a drilling mud, the method comprising:

• dispensing a spacer fluid into a first cell;
• applying pressure to the spacer fluid within the first cell;
• heating the spacer fluid within the first cell;
• measuring the conductivity of the spacer fluid;
• dispensing a known amount of drilling mud into a second cell;
• applying pressure to the drilling mud within the second cell;
• heating the drilling mud within the second cell;
• measuring the conductivity of the drilling mud within the second cell;
• transferring a portion of the spacer fluid to the second cell with the drilling mud;
• measuring the amount of spacer fluid transferred into the second cell;
• and
• measuring the conductivity of the drilling mud and spacer fluid combination.

A system for determining the water wettability of a mixture under downhole conditions, the system comprising:

• a first cell adapted to contain a fluid, the first cell including a first piston adapted to apply pressure to a first fluid contained within the first cell;
• a second cell adapted to contain a fluid, the second cell including a second piston adapted to apply pressure to a second fluid contained within the second cell, wherein a portion of the first fluid may be transferred from the first cell into the second cell;
• and
• a wettability readout apparatus connected to the system.