The Manor Spearfish Field, located in Southeast Saskatchewan, was originally discovered in 1987, with the drilling of several vertical wells that encountered remnant Spearfish sands on top of the Alida carbonates. A few vertical wells were produced at low rates. In 1992, several companies aggressively developed the pool entirely through horizontal drilling. Production peaked at 1,100 m(3)/d, then declined to just over I 10 m(3)/d. The pool has been the target of recent horizontal infill drilling. Several successful wells have been drilled, and Spearfish production from Crescent Point Energy operated wells has doubled from under 100 m(3)/d to almost 200 m(3)/d. Additional infill locations remain, both with new stand-alone horizontal wells and with horizontal re-entry wells. This paper reviews the predicted and actual results of five horizontal infill wells drilled in 2002. The methodology used in prioritizing the infill locations is also intended to illustrate the basic principles of reservoir engineering, and bow they can be applied through simple analytical methods to yield favourable results. The paper, as such, provides a review of the basic engineering steps needed in a successful infill well development project.