First Smart Liner Mono-Bore Completion in Giant Carbonate Reservoir in Abu Dhabi Provides New Opportunities for Tight Reservoirs Development

Abstract

One of the main challenges in the oil industry is to develop tighter carbonate reservoirs. There are several methods to improve oil recovery (IOR), the adoption of Novel Lower Completions in horizontal wells can be one of the best tools to maximize reservoir contact and to control unwanted fluids (i.e., water or gas). It is especially important in carbonate reservoirs where most of the time it is imperative to provide additional stimulation in order to produce the reservoirs economically. The main objective of the presented work is to provide an alternative type of completion that creates better flow and stimulation distribution along the horizontal hole, In addition, the movable parts were eliminated to reduce the integrity risk while injecting the acid job stimulation. In carbonate reservoirs, the standard method to improve reservoir permeability is through acid stimulation utilizing coiled tubing to place acid into the reservoir rock and improve the flow within the near wellbore area. This technique is costly and time consuming. Furthermore, in the specific case presented, there is the constraint of limited number of coiled tubing units where many times acid stimulation is delayed due to this fact. Installing the mono-bore segmented completion provides the capability to perform the job without the rig, only bull heading the acid utilizing high pressure pumps. There are several options to install lower completions in the oil industry for horizontal wells. Smart liner is presented as an alternative to the conventional pre-perforated liner. The smart liner design was done with a proprietary software and consists of a specific number of small holes distributed along the horizontal section to distribute the flow and provide better stimulation placement at higher rates improving "worm holes" creation and extension. The lower completion is equipped with swellable packers to provide segmentation in the horizontal hole for future requirements if needed such as zones shut off. After the successful installation in a water injection well, water injection was initiated to define a baseline to compare with the results after the acid stimulation. The paper presents the lower completion design, the acid stimulation program and the results before and after the stimulation is done without rig on site. Initial results after the stimulation are showing more than twice the injection rate after the job. This job was done without the use of coiled tubing providing a better acid stimulation along the horizontal hole. The 4-½ inches mono-bore completion is the first time that was done in the Asset, creating new opportunities to improve the stimulation and injectivity / productivity of the wells and consequent future Field development.