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Journal of Industrial and Environmental Chemistry | Volume 2
December 06 -07, 2018 | Dubai, UAE
Pet roleum Engineer ing, Oil and Gas
International Conference on
Joint Event
A novel approach for formulating CO2 foam based fracturing fluid by synthesized grafting
copolymerization to enhance its stability for HPHT shale reservoirs
Sahil Chaudhary
DIT University, India
An eco-friendly CO2 foam based fracturing fluid is developed
which can be used at HPHT conditions for shale reservoirs
with high goethite content. Results observed were compared
to the conventional fracturing fluids which were previously
published.
For the formulation of the fracturing fluid, gum acacia and
Lactic Acid is grafted together in the presence of Potassium
per sulphate (KPS). Base solution of the fracturing fluid is
prepared using 80% of CO2 liquid and 14% brine solution.
Lecithin is used to emulsify CO2 liquid and brine solution.
Grafted polymer is mixed with the base solution. An
Propylene glycol, oxygen scavenger, biocide, cross linker
and other additives has been added in smaller proportions
nearly 0.15% in the base fluid. Sodium Lauryl Sulphate and
Palmitic acid is added in the base solution as foaming agent.
After mixing the formulation at high rate for 10-15 minutes,
4-5% proppant is added in the developed fracking fluid.
The series of test has been conducted and the results are
compared with the conventional fracking fluid. FTIR has
been used for the characterization of grafted Copolymer
and the effective synthesized co-polymerization is shown by
the Infrared spectra of gum acacia (GA), Lactic acid (LA) and
grafted copolymer (GA-g-LA). Rheological properties have been
evaluated of the base gel and foam separately. In this paper, the
viscosity of grafted copolymer polymer fracturing foam at high
pressure high temperature (HPHT) as a function of surfactant
concentration, salinity, andshear ratearepresented. Pressurized
foam rheometer was used to find out the viscosity of CO2 foam
at different surfactant concentrations (0.25–1 wt%) and salinity
(0.5–8 wt%) over a wide range of shear rate (10–500 s−1) at
1500-3000 psi and 200-400 °F. The viscosity is found between
70-125 cP at for different concentrations. The foam quality
has been evaluated by adding 0.25% w, 0.5%w and 1%w of
surfactants. Half-life and proppant carrying capacity of the best
quality foam been determined at different temperature ranges.
Half-life time was found to be 145 minutes at 250ºF. The results
of effect of salinity and effect of shear rate have been discussed
in detail. The result showed that at foam quality of 80% &
70% proppant loading is 5.5%vol and 3%vol. Use of grafted
copolymer results in higher viscosity and proppant carrying
capacity which is beneficial for HPHT fracturing conditions.
The use of grafted copolymer enhanced the properties of
fracturing fluid. GA-g-LA is a novel approach and has not
been used in well stimulation industry. Grafting increased the
stability of fracturing fluid at HPHT wells. This could be brought
in practice in the coming time and can be used in deep wells.
e:
Oil & Gas 2018 &
Petroleum Engineering 2018, Volume 2
DOI: 10.4066/2591-7331-C2-006