Frac Packing: Best Practices and Lessons Learned From More Than 600 Operations

Abstract

Summary Frac packing is a completion technique that merges two distinct processes—hydraulic fracturing and gravel packing. The main challenge of a frac-pack completion is the successful creation of high-conductivity fractures with the tip-screenout (TSO) technique and the placement of proppant within those fractures and in the annulus between the screen and wellbore wall. This is further compounded by having to do so in an ultra high-permeability environment, in which high fluid-leakoff rates are evident. From 1997 to 2006, job data from more than 600 frac-packing operations, representing an estimated 5% of the worldwide total, have been compiled into a database. This paper reviews well information and key frac-packing parameters. Also summarized are engineering implementations and challenges, best practices, and lessons learned. Essential frac-pack design parameters that were attained from the step-rate test (SRT) and minifrac test are evaluated. These include bottomhole pressure, rock-closure time, and fracturing-fluid efficiency. Downhole pressure and temperature are also discussed because of their importance to the post-completion efficiency evaluation and fracturing-fluid-optimization phase. Worldwide case histories are provided that demonstrate how to both deploy different frac-packing systems and pack the wellbore during extreme conditions with improved packing efficiency and a higher chance of success.