Formation evaluation while drilling
A sample module for a sampling while drilling tool includes a sample fluid flowline operatively connectable between a sample chamber and an inlet, for passing a downhole fluid. A primary piston divides the sample chamber into a sample volume and a buffer volume and includes a first face in fluid communication with the sample volume and a second face in fluid communication with the buffer volume. An agitator is disposed in the sample volume for agitating the sample fluid. A secondary piston includes a first face in fluid communication with the buffer volume having buffer fluid disposed therein and a second face.
1. A sample module for a sampling while drilling tool positionable in a wellbore penetrating a subterranean formation, comprising:
a sample chamber having an inlet configured to receive a downhole fluid from a sample fluid flowline;
a primary piston slidably disposed within the sample chamber and dividing the sample chamber into a sample volume and a buffer volume; and
an agitator disposed in the sample volume and comprising an inner core and an outer body, wherein the outer body comprises a material having a lower hardness than an interior wall of the sample chamber.
2. The sample module of claim 1 wherein the inner core comprises a material having a greater hardness than the material of the outer body.
3. The sample module of claim 1 wherein the outer body substantially comprises PEEK (polyetheretherketone) and the inner core substantially comprises metal.