Self-suspending proppant transport technology comprises a 1-micron to 3-micron thick, residue-free, water-swellable, shear-stable polymer coating applied to a proppant substrate. The polymer swells upon contact with water, temporarily reducing the proppant's effective specific gravity. This lower effective specific gravity enables uniform vertical proppant distribution throughout the fracture. The polymer coating, which is broken and unzipped with conventional oxidative breakers, flows back freely with the frac fluid.
This paper examines how the use of this water-swellable polymer coating around a proppant minimizes the negative affect on proppant pack conductivity and formation permeability that occurs with common viscosifying agents and friction reducers.
This paper also documents how the technology increases stimulated reservoir area and increases production by reducing net formation damage near-wellbore and deep in the formation.
These dynamics have been evaluated and confirmed through laboratory data and field-trial wells that were completed with various combinations of frac fluid systems. Results show a complete removal of the water-soluble polymer coating, preventing formation damage.
In this paper, the authors include detailed laboratory test methods and results, including static and dynamic viscometrics on supernatant and proppant-laden fluids, settled bed height comparisons, and loss on ignition. Regain conductivity and retained permeability tests are compared with conventional fluid systems. Further, these results are confirmed by analytical test methods. These tests confirm the self-suspending proppant polymer coating leaves little to no residue in the formation.
Self-suspending proppant technology field performance data confirm a better production scenario in the absence of formation-damaging fracturing fluid. Further, operators achieved the best results when only using this new technology without other proppant or other fluid systems. In 3 formations after 18 months, 6 months, and 5 months, hydrocarbon production in the wells with self-suspending proppant technology increased 45%, 7%, and 43% compared with their respective offset test wells.
The test results and field data described in this paper prove the value of reducing formation damage to improve well performance.