Abstract
Over the last several years there have been many technical developments in horizontal completion methods. These developments have been designed to better stimulate the entire horizontal interval. For cased and cemented applications, composite plugs have provided the ability to segment the horizontal wellbore into sections and divert the stimulation as designed. However, the process of setting a plug on coiled tubing (CT), perforating, stimulating and then repeating the process for the required number of stages to optimize production and then running back in with CT to remove the plugs can take weeks to complete. For open hole applications, horizontal stimulations have relied solely on bullheading in stages in an attempt to generate multiple fractures. This has proven in many cases to only stimulate certain sections of the wellbore leaving much of the horizontal section unstimulated.
A new completion system has been deployed in over 300 wellbores in various producing formations, such as sandstone, limestone, shale, dolomite and coal. This system uses a series of mechanical open hole packers deployed on the production liner with fracturing or stimulation ports located between the packers that allow for stimulation in each desired interval. Without the requirement of cementing the liner in place, all the problematic issues associated with cementing are eliminated. Additionally, the use of mechanical packers provides positive mechanical diversion at high differential fracturing pressures. The system has also been designed, so all of the fracturing or stimulation treatments along the horizontal wellbore can be pumped in one continuous operation, thus minimizing the associated risks and optimizing the efficiencies of both the personnel and equipment needed to perform the work. This paper will detail the operational efficiencies and reliability of this novel completion system, as well as analyze the cost benefits and production increases that have been noted.
