Hello guys! Today we're going to take a look at what is mud logging in oil and gas.
There are different ways to analyze the downhole conditions and to get more information about the
wellbore formation while the well is being drilled. A few ways to achieve this is to take advantage of
measuring while drilling (MWD) and logging while drilling (LWD) or perform mud logging.
So what's mud logging? Mud logging involves analyzing raw cuttings that are coming to
surface with the drilling fluid. Drilling fluid is pumped while drilling the well to control the
downhole pressures, lubricate the wellbore and the drilling string and to bring the cuttings from the
bit to the surface to keep the wellbore clean from all this debris. These raw cuttings are analyzed for
their composition and to find their physical properties such as porosity,
permeability and potentially use this information to improve the drilling rates and prevent any
possible kicks. Mud logging is also used to confirm that the well is being drilled in the right formation
and to get a better understanding of the lithology and the fluids trapped in the formation. In addition to
analyzing the rock samples mud logging can also involve analyzing the gas coming to the surface
with the help of gas chromatography to quantify the hydrocarbons in those gas samples and as well
as to find their composition. Some mudloggers have a degree in geology or engineering while
others don't have any formal education and they just have a lot of field experience from working
on drilling rigs or for the service companies. Often mudloggers will work with
geologists and supply them with rock samples when they need it.
Both office and wellsite geologists rely on the reports from the mudloggers to perform more
in-depth well drilling analysis while the well is being drilled. The mudlogging reports usually have
information about the drilling speeds or rate of penetration, rock composition, physical properties
of the rock as well as information about the hydrocarbons detected by gas chromatography.
Depending on well complexity sometimes geologists might perform similar tasks to the mudloggers.
Some new grads with degree in geology start working in the oil and gas industry as mudloggers
and later become geologists. This helps them to gain field experience and a better understanding
of the entire drilling process and makes it easier for them to transition to something
else later after a few years working as mudloggers. In general, if you have a degree it's
usually, a good idea not to get stuck as a mudlogger for a long time mainly because
the salaries are not that great and everybody on location usually makes more than you. Most mudloggers
stay on location while the well is being drilled. They usually stay in special trailers
and they work usually 12 hours on and 12 hours off. However, in some cases when the well is very simple
and samples don't have to be collected every few hours and only collected a few times per day
mudloggers might be required to provide a full 24 hour coverage. The rate at which the rock samples
are collected depends on the speed of the drilling as well as well complexity. This means that you
will usually only work several hours during your shift and the rest will be just kind of spent
waiting until you need to collect your next samples and there is also quite a bit of downtime
when the drill bit for example gets changed or something goes wrong during the drilling operation.
The rotational schedules for mudloggers are usually
two weeks on and one week off however it can be different depending on the company you are working
for. In some cases, you might be required to stay on location for the entire drilling operation. So
guys this is just a basic overview of what's mudlogging, what mudloggers do in location, and how
you can become one. Thank you guys for watching this video and I'll see you guys later. Bye!