Over the last two years the increase in openhole interventionless horizontal completions in the shale markets has lead to higher production rates at lower completion costs for operators. In areas where wells are being air-drilled, specific techniques of using hydraulic set packers and sliding sleeves has proven to be a viable, low-cost, interventionless solution to complete when the wells are likely to be a gauge hole. However, in areas where the horizontal wells use foam instead of air because of the sensitivity of the shale, typically the wellbore is non-gauged and may lead to operational failures when trying to isolate the wellbore with hydraulic set packers because of the limitation of the expansion of the element package. The advances in the use of swellable elastomer packers provide an ideal solution for isolating these non-gauged holes for the completion process. But, as mentioned, there is sensitivity to the shale in these wellbores, and applying the typical hydrocarbon fluid to the formation to swell the swellable elastomer packers may cause a detrimental effect to the formation.
To overcome the issue of isolation in non-gauged holes without damaging the shale formation, an interventionless solution was incorporated using sliding sleeves, swellable elastomer packers, and development of a new shale optimized fluid system to swell the packers. The shale-optimized fluid is an effective low-leakoff fluid that causes minimum physio-chemical damage to the shale while increasing the optimization of the swell time of the packers. This paper will discuss the development of this new completion process for use with foam-drilled openholes that are non-gauged and case history information of applications that have been run in the Lower Huron shale formation.