to 210C, the AD8229
from Analog Devices is being touted the first instrumentation amplifier
designed and manufactured for hot, harsh and hostile environments. This
1.0-nV/vHz low-noise device is specifically targeting extreme, hostile
environments such as down-hole oil drilling, jet engines and space exploration.
AD8229 is truly a breakthrough product for the oil exploration industry," says
Jun Liu, General Manager of Qingdao Zitn Micro-electronics Co. Ltd. "It is not
a retrofit of existing components. It was designed from the start for
high-temperature environments. What this means to Zitn is that we will be able
to operate our equipment longer with less repair time resulting in significant
past, designers have been forced to meet the challenges of rugged, noisy
high-temperature environments with components not specifically designed for
high-temperature conditions or were designed to operate at lower commercial
grade temperatures. The AD8229 is unique because it solves some of the most
difficult problems faced by engineers designing electronics for extreme hot,
harsh and hostile environments to greatly improve maintenance and operation
trends we are seeing in the oil and gas industry is that, when exploring for
new sources of energy, companies are often forced to do it in more difficult
environments," says Pam Aparo, Segment Marketing Manager for Analog Devices'
Instrumentation Business. "Companies are forced to drill deeper or at a more
horizontal angle which reduces how efficiently they can cool the drilling
apparatus. That's driving the need for components to do measurements at higher
temperatures than ever before."
challenge is that the control electronics are housed in close proximity to the
point of impact. At the bottom of the well or the end of the drill tunnel,
classes of drilling such as wireline drilling and logging while drilling (LWD)
or measurement while drilling require high temperature electronics.
these applications have in common is exposing the electronics to high pressure,
high temperature (HPHT). Working several miles underground, fixing and
re-inserting the drills is a huge problem, and estimates put the total cost for
this type of maintenance operations at millions of dollars per day in the case
of a failure. It's not possible to totally control the systems but goal of the
electronics is to stay operational in these harsh environments.
is a major challenge, along with the type of signals and demanding work done so
far underground," says David Chan, marketing manager for Analog Devices. "Our
systems are very low noise and we're been able to squeeze it down to the point
where you can actually detect conditions that even on the surface at room
temperature would be difficult to deal with."
includes gamma ray detection and NMR which is the oil drilling version of an
MRI where the requirement is to fit that level of instrumentation and
sensitivity into a tube 12 inches in diameter. The challenges are quite
extreme, not just the high temperature but also the noise performance that goes
along with it.
five to ten feet from the drill head means that the control and instrumentation
electronics are subjected to a huge amount of mechanical stress and vibrations
in the structure itself. Fluids are flowing back and forth to provide cooling
or lubrication during the drilling operation. Plus the application is measuring
the radioactivity of the formation around the unit, so there are many noise
sources that need to be screened out," Chan says.
as the challenges on the component level, previously when drills only went up
to 175C, existing silicon that was military rated could be stretched and used
in the application. The goal would be to see if the performance held up,
characterize the stresses and subject the system to extensive testing.
from 175 to 210C is much harder because fewer components are available to
handle the higher temperatures," says Aparo. "This is one of the first
components designed specifically for that elevated temperature range. We used
an SOI process and one of our ADI fellows with over 30 years of experience was
a part of our design team."
AD8229 amplifier is best-in-class in all three performance categories for high-temperature
applications including CMRR (common mode rejection ratio), voltage offset and
input noise. CMRR performance is 100 dB over the temperature range of 55 to 210C. The AD8229 input voltage offset
varies by only 100-nV/C over the entire temperate range. Input noise is
1.0-nV/vHz making the amp ideal for sensors that read faint signals such as
those used in down-hole drilling, nuclear magnetic resonance spectroscopy and
gamma ray detection.
to watch ADI Fellow Moshe Gerstenhaber explain how the AD8229 meets the design
challenges of high-temperature environments.