Formation evaluation while drilling

摘要

A sample module for a sampling while drilling tool (230) includes a sample fluid flowline (310) operatively connectable between a sample chamber and an inlet (1206), for passing a downhole fluid. A primary piston (1214) divides the sample chamber into a sample volume (1230) and a buffer volume (1232) and includes a first face (1218) in fluid communication with the sample volume (1230) and a second face (1220) in fluid communication with the buffer volume (1232). A secondary piston (1222) includes a first face (1226) in fluid communication with the buffer volume (1232) having buffer fluid disposed therein and a second face (1228).