TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAn operator company and service company have used concentric alternative flowpath technology to successfully gravel pack five horizontal openhole completions where reactive shales have caused problems in the past. These horizontal openhole gravel packs were the first for the Nigeria operator company, and were the service company's first use of this concentric alternative flowpath system in a horizontal openhole completion. This paper discusses operational procedures, best practices, and lessons learned during the completion of these wells. Early attempts to manage sand production with predrilled liners had failed, and subsequent attempts to control sand with stand alone screens had also failed. Using a gravel pack was another alternative sand control method, but the presence of reactive shales, a known problem in the field, had to be addressed. Concentric alternative flowpath technology has effectively controlled reactive shales and gravel packed five wells in this field. In these cases, an engineered predrilled outer shroud was installed for hole cleanup and displacement before running the screen and gravel packing. The key factors in successfully completing these wells that will be discussed in detail include:• Improved drill-in fluid designs and effective casing cleanup and displacement methods • Openhole and casing cleaning and preparation prior to running the outer shroud and screen • Outer shroud and screen installation process • Gravel packing method and procedure