SIMPLE APPROACH TO THE CLEANUP OF HORIZONTAL WELLS WITH PREPACKED SCREEN COMPLETIONS

Openhole completions with prepacked screens are increasingly the compl etion of choice for horizontal wells requiring sand control. For maxim um productivity from these wells, preventing mud damage to the formati on and the screens or removing it before bringing the well onto produc tion is vital. A common industry approach to this problem is to displa ce the drilling mud to an aqueous clear fluid before production, typic ally followed by a breaker fluid. This paper details an alternative ap proach: bringing the well on without cleanup. The paper outlines the d ecision-making process, shows how the drill-in-fluid and cleanup opera tions are designed, explains how laboratory testing can be used to sup port the design philosophy, and highlights that quality control of the mud system while drilling is critical to the success of such a well. Case histories in two very different reservoirs are presented that ill ustrate the success of this approach.