Challenge

A customer in the Powder River Basin sought higher performance in the category of high brine tolerant friction reducers. The friction reducer previously utilized by the customer was selected primarily based on price but exhibited suboptimal performance relative to tubular friction pressure at high pumping rates. The customer recognized the risks of utilizing incompatible friction reducers with higher treating pressures that could cause stress on surface equipment and compromise casing integrity. Inferior and incompatible polymer chemistries can also cause formation damage if they do not decompose properly which will lead to poor well performance. Fluctuations in water chemistry reported by the customer magnified the need for a versatile product with optimal friction reduction properties delivered at a reasonable cost per treated barrel.

Solution

The customer enlisted Rockwater to identify a potential replacement for the customer’s current friction reducer. This process began with the collection of source water samples for a complete FluidMatch™ analysis. From the samples, fluid rheology, dynamic friction loop testing, kill studies, and a full water profile provided a basis for a compatible product recommendation. During the flow loop analysis, the previous friction reducer exhibited a lack of performance stability over longer pump times indicating the polymer shear stability and compatibility was not optimized. To improve fluid performance, Rockwater’s potential recommendations were reviewed for sensitivity to shear, degradation over time, and any interaction with the water chemistry at a molecular level. In this case, a sub-group of viscoelastic friction reducers were identified that perform in the same multivalent cationic, sulfate, and bicarbonate categories.

A friction flow loop analysis of both products revealed a slight improvement in friction reduction with Rockwater’s selected product, particularly beyond the five-minute mark.