Openhole horizontal completions using external casing packers (ECPs) for zonal isolation are a growing trend in the oil industry. This style of completion is installed with slotted pipe or screen across production intervals that are isolated by ECPs. This method, integrated with standard liner hanger equipment set in one trip, allows for production at a lower completion cost, but it also minimizes the options for water shutoff or shutoff of a naturally depleting interval.
As companies continue to implement openhole horizontal completions, they look for alternatives that will provide precise zonal isolation while reducing installation time. This paper addresses an alternative isolation method wherein nonelastomeric sliding sleeves replace the slotted pipe between the ECPs. This method enables the operator to increase production while shutting off undesired intervals, thus fully optimizing the production program. With the use of coiled tubing and hydraulically actuated tools, sliding sleeve manipulation can be accomplished in long-reaching horizontal wellbores. The manipulation of these sleeves can increase production while shutting off undesired intervals.
These sliding sleeve isolation systems have been installed and successfully operated in numerous horizontal wellbores in the Rocky Mountain Region and worldwide. Sliding sleeve systems have been successfully manipulated using coiled tubing methods, even when placed at 90° angles, true horizontal. The capability of shifting sliding sleeves in the horizontal position by utilizing coiled tubing hydraulically actuated shifting tools will be demonstrated in the paper. This allows for the selective opening or closing of multiple sleeves in a single trip. Utilizing sliding sleeves to control well inflow can improve well economics by shutting off unwanted water or gas production.