pages 87-93_Layout 1 1/9/2019 4:06 PM Page 87 Defending Against Well Interference Strategy Defends Wells From Frac Hits By Peter Bommer and Marcus Bayne SAN ANTONIO, TX.-The effects of well interference between existing producing wells and newly stimulated wells are of growing concern as full-density development accelerates across North American resource plays. Strategies to mitigate the negative effects of interference are becoming increasingly important as frac hits become more frequent. In the North Fork Field in the deep center of the Williston Basin in east-central McKenzie County, N.D., Abraxas Petroleum Corporation has experienced numerous examples of stimulation interference as its development operations have progressed to the full-density phase. Stimulation interference is defined as any increase in pressure occurring in a well as a result of stimulation activities in an offset or nearby well. While such interference has not necessarily had a lasting effect on legacy production, in some cases, it has resulted in solids migrating into legacy laterals and the need for costly remediation. JANUARY 2019 87