WELLOG
MEMS
Revised
11-07-2016
© WELLOG
2007-2016
All
Rights Reserved
WHAT ARE MEMS
DEVICES?
MEMS are
surface-micro-machined integrated-circuit accelerometers. The device consists
of two surface micro-machined capacitive sensing cells (g-cell) and a signal
conditioning ASIC. The g-cell is a mechanical structure formed from
semiconductor materials (polysilicon) using semiconductor processes. It can be
modeled as a set of beams attached to a moveable central mass that moves
between fixed beams. The moveable beams are deflected from their rest position
by subjecting the system to acceleration. As the beams attached to the central
mass move, the distance from them to the fixed beams on one side will increase
by the same amount that the distance to the fixed beams on the other side
decreases. The change in distance is a measure of acceleration.
MEMS devices
have recently found many applications in electronics. WELLOG is finding many
applications for these devices in the well logging industry.
WHAT DO THEY
LOOK LIKE?
Click here à ADXL213
Click here à MEMS PCB for a view of a 3-axis MEMS
printed circuit board currently in use.
WHAT CAN THEY
BE USED FOR?
MEMS sensors
can produce an output that is related to gravitational force, also known as
gravitational acceleration. The z-axis output decreases by an amount equal to
the angle of deviation from the vertical component of gravity. WELLOG uses a
proprietary design to create a linear angular output that has resolving
capability to less than one degree. Compass systems with tilt compensation are
now available at WELLOG. See our web page on well navigation.
Typical
logging with deviation tools uses the following procedure: The tool is
suspended before entering the well. Next, the tool is lowered to the bottom of
the well. Deviation readings are taken at predetermined foot or time stations
in the well. A Deviation log may contain readings taken at hundreds or
thousands of stations. See the webpage on Deviation.
WELLOG has a Navigation tool with 4GB of internal
memory. The 4GB internal SD Flash memory can be removed and read as a standard
text file on a PC.
Contact info@wellog
for more information.