Fracturing Water Quality Western North Dakota Water Resources Opportunities 10 Dec 2009

1. Fracturing Water QualityWestern North Dakota Water Resources Opportunities10 Dec 2009 Mike Eberhard P.E. Technical Manager Denver, CO

2. Water Considerations • Water sources • Well, municipal, river, reused, etc. • Environmental Impact • Costs to acquire and dispose • All inclusive • Storage and handling • Pits or tanks • Trucking or pipeline • Regulatory requirements • Federal, State, BLM, etc.

3. Water Quality Concerns • Treatment Type • Gelled fluid or water frac • Bacteria, scaling, residual chemicals • Water analysis • TDS, hardness, cations, anions • Scaling tendencies • Consistency is imperative

4. Water Quality Guidelines * Limits are interdependent

5. Bacteria • Can double in population every 20 min • Can cause formation damage and H2S • Significant problem in reused fluids

6. Typical Gelled Frac Fluid Chemistry • Base water • Temporary clay control • Biocide • Scale inhibitor • Gelling agent • pH buffer • Crosslinker • Surfactant • Breaker

7. Flowback Water/Produced Brines • Mixing different waters may exaggerate scaling problems • Storage and handling • Water treatment • Filter as required • Bacteria shock then store • Retreat for bacteria on fly • Remove bad actors • (Ca, Mg, Ba, Sr, Fe) • Add scale inhibitors as needed, based on source water • Lab testing • Cores for formation damage • Chemical compatibility • Dilute w/ fresh water to get below limits

8. Bakken Water Analysis Bakken Produced Water – BPW, Referenced Municipal Water - RMW

9. Formation Water Scaling Tendencies