Smart well completions include downhole gauges, sliding circulation valves, open/close safety valves, control lines, and fiber cables or a combination of these. One method for deploying this downhole equipment is achieved by affixing it to the outside of the casing and permanently cementing it in place; however, a challenge with external-casing equipment is helping to prevent damaging the installation if perforating is the chosen method to establish effective communication between the wellbore and formation. This challenge is further magnified when the well is drilled near-vertical and run on the outside of a large-diameter casing.
This paper discusses the execution of an engineered design of service to perforate a 7-in. diameter production smart well completion using 4 5/8-in. tubing-conveyed perforating (TCP) gun assemblies. As part of the completion design, the TCP gun assemblies were hung below the bottomhole assembly (BHA). A fiber-optic (FO) package was run external to the casing, and the well had a deviation less than 5°, preventing the use of high-side logging tools.
Various options, discussed later in this paper, were considered to locate the azimuthal orientation of the fiber cables, including a new-to-market technology tool. Ultimately, a method was devised to engineer an ultrasonic logging tool to be deployed in conjunction with a north-finding gyroscope tool to accurately determine the location of the external-casing equipment. TCP guns were then hung below the tubing string, which included a fixed-point orienting sub that could be used to confirm the direction of all the planned perforations. To achieve operational and economic objectives, the TCP assembly was dropped to the bottom of the well so that the well could be immediately placed on production without killing the well or retrieving the spent perforating guns.
The well was successfully perforated without damage to the external-gauge equipment, showcasing that collaborating with the operator, and understanding their value drivers, led to an engineered solution that maximized the asset value of the well.