DrySlik Friction Reducer Dosed on the Fly in the Eagle Ford


Hydraulic fracturing is instrumental in delivering on today’s energy demands.

Driven by an intense focus on reducing costs and improving well productivity economics, the trend is completing longer laterals with higher injection and proppant loading and ever increasing pump rates. Friction reduction chemicals (FR) are nowadays an essential element in well stimulation.

Innovation is moving fast since the market shifted from gel and hybrid fracs to slik water fracs. Operators are challenged to increase the reuse of produced water to cut back on fresh water consumption, and demand that frac fluids provide elevated viscosities to boost proppant transport.

Highland Fluid Technology (HFT) provides specialty chemistry in conjunction with proprietary hardware and has developed a cost-effective dry FRs as an alternative to the incumbent liquid FRs. Dry FR has a number of operational, environmental, and direct cost savings. These advantages including eliminating about seven out of the eight trucks transporting FR to the wellsite; eliminating the hydration unit for slick water fracs; a smaller location footprint; lowering heating expenses, reducing separator service charges as the flowback lacks the oil sheen from liquid FRs; and operational and reservoir performance improvements.

DrySlik 3.5, a 30% AMPS anionic copolymer, is finely ground, which is a key to high activity and quick hydration – even at low ambient temperatures in high-salinity brines and produced water. In addition, DrySlik 1235 and DrySlik 3.0 are anionic copolymers that are ideal for medium brines and fresh water applications. An associative thickener can be blended to boost the low-end rheology for enhanced proppant transport. Cationic applications are serviced with DrySlik 2358.

Laboratory flow loop testing suggests that even in Marcellus produced water – generally perceived as tough water for anionic FRs to work due to presence of iron, Barium, Calcium, Boron – a 77% friction reduction is achieved with DrySlik 3.5 that only tapered off to 73% after 10min of flow. In comparison, many liquid FRs that are double the cost to achieve 60%, falling off to 40% for incumbent anionic and cationic FRs.

Dry FR is dosed into the frac water using a dry-mixing system. Recently, Highland Fluid validated its DrySlik and novel dry-add system at an Eagle Ford wellsite. Product and equipment both performed well during testing-intervals in about 1/3 of the stages. Accurate on-the-fly dosing was achieved, reducing the treatment pressure. Direct electronic communication between the dry-add mixer and the blender allows for automated dosing adjustment based on the blender’s suction rate.

Accurate dry-on-the-fly dosing of DrySlik was achieved thanks to real-time hopper load cell sensor feedback with automated rotary valve-speed adjustments to deliver on the required dosing concentration. The high-degree of automation safeguards against unanticipated wellsite events and provides operational ease for the operators. The mixing hoppers are fully enclosed to deal with inclement weather and mitigate respiration hazards, and the unit is powered with a Cat 4 diesel engine to reduce emissions.

While the dry-mix-on-the-fly trailer was operated directly on behalf of the nation’s largest independent operator, Highland also equips pumpers with DrySlik and its proprietary Dry-Add mixing systems, either for rent or purchase.

FR is just one of the crucial frac fluid additives. Highland also provides shale biocides, de-foamers, inhibitors and corrosion inhibitors which can be blended with DrySlik FR.


Achievements:
– Dosed dry friction reducer (FR) at an Eagle Ford wellsite
– Mixed on-the-fly the required concentration of DrySlik FR thanks to automated dosing based on blender suction rate
– Achieved the required treatment pressure reduction

Background:
– Mobilized a fit-for-purpose dry-mixing trailer together with DrySlik FR at an Eagle Ford wellsite
– Established MSA with the nations largest independent operators
– Dosed DrySlik in frac water supplied to the blender at a 10 bpm constant rate at concentrations to match the desired set points in fully-automatic fashion

DrySlik
– Finely ground for fast hydration i.e. 15 sec for dry-on-the-fly mixing and eliminating the hydration unit
– Salt tolerate and compatible with many produced waters
– Shear-resistant, robust copolymer for performance in long laterals and deep wells
– High temperature tolerant
– Eliminating the usual carrying fluid reduces the number of trucks on the road and reduces cost associated with separators during flow back.