Apparatus and methods for assessing contamination of formation fluid. A downhole sampling tool is operated to draw fluid from a subterranean formation into a chamber of the downhole sampling tool. The downhole sampling tool is then operated to discharge the fluid from the chamber while monitoring pressure of the fluid and volume of the chamber. Contamination of the discharged fluid is assessed based on the monitored fluid pressure and the monitored chamber volume.

A downhole fluid sampling system with hydraulic actuation can be used to collect one or more samples of formation fluid during a well operation. The sampling system can be within a downhole tool deployed in a wellbore of the well operation. Then sampling system then can collect a first sample from the flow of formation fluid from the wellbore using a first sampling chamber of a sampling unit in the sampling system. The sampling unit can define a set of sampling chambers including the first sampling chamber and a second sampling chamber. A piston of the sampling system that actuates on hydraulic fluid can advance the sampling unit by a predefined distance from a first position associated with the first sampling chamber to a second position associated with the second sampling chamber. Subsequently, the second sampling chamber can collect a second sample from the flow of formation fluid.

Techniques for controlling lost circulation while drilling include while drilling a wellbore, encountering a high-loss circulation zone by a bottomhole assembly; responsive to encountering the high-loss circulation zone, releasing a first lost circulation media retained within the bottomhole assembly; and receiving a second lost circulation media, by the bottomhole assembly, from circulation fluid circulated from a topside facility.

A downhole fluid sampling system with hydraulic actuation can be used to collect one or more samples of formation fluid during a well operation. The sampling system can be within a downhole tool deployed in a wellbore of the well operation. Then sampling system then can collect a first sample from the flow of formation fluid from the wellbore using a first sampling chamber of a sampling unit in the sampling system. The sampling unit can define a set of sampling chambers including the first sampling chamber and a second sampling chamber. A piston of the sampling system that actuates on hydraulic fluid can advance the sampling unit by a predefined distance from a first position associated with the first sampling chamber to a second position associated with the second sampling chamber. Subsequently, the second sampling chamber can collect a second sample from the flow of formation fluid.