American Oil and Gas Reporter - June 2015 - 22

TECHCONNECTIONS
Advancements Expand
Applications Of Polymer Gels
Beyond Water Control
At an event hosted by the University of Kansas Tertiary Oil
Recovery Program in conjunction with PTTC, I was pleasantly
surprised to listen to two presentations on the effective use of polymer gels. As I listened, it became clear that, as with other wellestablished technology, polymer treatments have been evolving
tremendously. In fact, polymer gel service providers have made
significant advancements in the development and chemistry of
their products and services.
In a presentation titled, "What's New in Polymer Technology," Daniel French from Polymer Services discussed the history of polymer treatments, pointing out that the technology was
developed by Phillips Petroleum in the 1960s to control water production. In a secret operation to shut off water production in the
Bemis-Shuts Field in Kansas, Phillips pumped the first polymer
job in the late 1960s. French highlighted how the gels of today
had evolved from early biopolymers to gels that are mixed in water and cross-linked with a trivalent chromium ion. These gels are
being used around the globe now.
Typically, operators are looking to shut off unwanted water
in producing wells. This is what Phillips was after in the 1960s.
However, polymer treatments also can be used to improve the distribution of drive fluids while doing flood treatment on a well.
This conformance control is key when one is designing a water,
carbon dioxide, nitrogen or chemical flood.
French went on to explain that polymer gel chemistry varied
from company to company, but typically these gels are mixed on
the surface and can be developed specifically for a variety of reservoir conditions. The gel strength is a function of polymer concentration, and can be created for high-pressure and high-temperature environments-something early polymers had difficulty
achieving.
French said the system his company used was a modified
trichrome system known as Waterblock. This system is based on
the technology developed by Phillips, and is more robust and forgiving than previous technologies. While this technology was developed to be effective in hostile environments, variations of the
chemistry also have been used to make it effective in shallow, lowtemperature wells.
Because these treatments are intended to last the life of the well,
it has been important to develop stable polymer treatments. French
suggests that when developing a polymer treatment for a particular well, prewetting the gel particles is an effective means to generate a more stable cross-linked gel.
In another presentation, titled "The Combined Use of Gel Polymer and Nanofluids to Increase Oil Recovery in Natural WaterDrive, Waterflood, Chemical Flood and CO2 Flood Reservoirs," Jay Portwood with EOGA IOR Services discussed his company's complex nanofluid chemistry and cited examples of its application. Portwood agreed that in addition to shutting off unwanted
water in producing wells, conformance control and sweep efficiency improvement were key to effective production of certain
wells.
When designing a job, Portwood says the gel should be de22 THE AMERICAN OIL & GAS REPORTER

"Polymer treatments also can
be used to improve the

distribution of drive fluids.

veloped based on rock type. For example, while a weaker gel may
be used for permeability modification, a stronger gel should be
used for a reservoir with a larger void space. Portwood also asserts that during gel applications designed to improve the in-depth
distribution of a drive fluid (water, CO2, nitrogen and chemical
floods), a complex nanofluid additive can aid the overall process
and improve production. Complex nanofluid (CnF) additives are
patented combinations of surfactant, solvent and water that are
designed specifically to enhance oil and gas production.
Portwood highlighted how CnF technology combined surfactant, solvent and water in a nanoscopic structure. He showed
how the surfactant base lowered interfacial tension and changed
the contact angle of the oil against the rock surface. The solvent
dissolves any organic deposits and changes wettability. Finally,
the nanodroplet evenly treats a large surface area and permeates
the pore spaces of the well.
CnF droplets are much smaller than the droplets incorporated in a normal emulsion. Since they are smaller than the pores
of most oil bearing formations, they are better equipped to place
solvent throughout the reservoir without the risk of formation damage.
Portwood discussed how CnF additives delivered nanoscale
droplets of solvent and surfactant during the water phase of an
operation. The surfactant modifies the interfacial tension between
the oil and water, and the solvent is delivered to the surface, penetrating any hydrocarbon on it.
Whether one is using a traditional polymer treatment to shut
off water during production or nanodroplet additives designed to
reduce interfacial tension and increase mobility of oil in the reservoir, operators have many choices as they select the options that
best suit their needs. Advancements in polymer technology in the
past 30 years have made the traditional formulations more reliable and effective, and new innovations are paving the way for
the next chapter in enhanced oil recovery.
❒

JEREMY VISCOMI is director

of technology transfer for the
University of Kansas Tertiary
Oil Recovery Program and is
Midcontinent regional director
for PTTC. He has more than a
decade of experience in developing and organizing technical
conferences and special events.

American Oil and Gas Reporter - June 2015

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