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Smart Wells and Techniques for Reservoir Monitoring 277

regularly the range of improvement is between 30% and 60%. IOR/EOR
has are divided three main categories: thermal fluids (steams and in situ com-
bustion), chemical fluids (alkaline, polymers, and surfactants), and gas injec-
tion (CO 2 ,N 2 , and fuel gas).
Use of EOR/IOR methods began in the 1950s, but the 1970s saw a dra-
matic increase in IOR implementation. During the 1980s and 1990s, oil
companies used cased-hole logs, PLTs, pressure transient tests (PTT), and
down-hole pressure gauges to evaluate the water and gas injection fronts.
All of these techniques monitor production response, well to well (point
to point), and are logged in the well sporadically over time (once per year)
but are unable to predict water or gas breakthrough with accuracy. There-
fore, the control mode was generally reactive and rarely proactive. The vol-
umes of data managed by these tools do not exceed the kilobytes/days.
Modern EOR/IOR processes include a series of technology, hardware,
and software specially designed for this operation, which allows real-time
data capture of massive volumes of data (e.g., megabyte of data per minute).
Using fiber optic cable in horizontal wells, temperature, pressure, and strain
can be monitored and logged at every meter, detecting with high precision
and on time, the segment of the well that is being invaded with unwanted or
injected fluids. Some examples of these technologies include the following:
• Real-time use of a series of chemical, thermal, and ultrasonic sensors to
monitor fluid chemical properties, such as liquid pH, chlorides, solids,
minerals, ions, cations, temperature, stream quality (x%), wax,
asphaltene, proppant, sand, tracers, etc.
• Down-hole fiber optics. These technologies include: (1) distributed
temperature sensing (DTS), which captures several megabytes/day to
register fluid temperature behind the casing along the horizontal and
has been recently applied to monitor hydraulic fracturing and (2) distrib-
ute acoustic sensing (DAS), which collects terabytes/day to register strain
sensing along the horizontal section.
• 4D time-lapsed seismic, micro-seismic, cross-well seismic, and vertical
seismic profiling.
The combination of ICVs/ICDs with any of the above technologies has
generated unprecedented information and analysis that was previously
impossible to decipher because of data-processing technology limitations
(Regtien, 2010; Clark et al., 2010). Smart IOR/EOR could be defined
as a process that uses a series of smart components and automated function-
alities, which cover the full DOF chain, including remote sensing, data
acquisition, workflow automation, visualization, and collaboration (where