Effective well completion design is crucial to maximize reservoir recovery rates, with many exploration and production (E&P) companies utilize multilateral technology to achieve this important objective. However, as fields mature and more wells are drilled, cost-effective reservoir management becomes more challenging.
The E&P companies drill dedicated wells to collect important data for reservoir planning, with well logging conducted periodically to monitor the changes in the reservoir. Observation wells have been drilled in different locations to monitor the reservoir and assist with planning and intervention decisions. However, these wells can be costly and occupy valuable space that could be utilized for production. An alternate technique enables E&P companies to drill a pilot hole, perform all the necessary logging, and obtain the required reservoir information. The pilot hole is then plugged and abandoned. Even though this technique saves the space occupied by a dedicated observation well, the collected data only remains valid for a limited period due to potential changes to the reservoir.
The production and completion engineers have further leveraged this solution and developed a new multilateral well technology that addresses these challenges. These enhanced technologies allow wells to be completed with a pilot hole (vertical) drilled for reservoir evaluation throughout the life of the well, with permanent downhole monitoring system (PDHMS) with permanent downhole monitoring gauges (PDHGs) installed for pressure and temperature monitoring, while the horizontal lateral functions as an oil/gas producer. Combining the observation and producer wells into one well results in cost savings and maximum reservoir recovery and management. In addition, the capability to access the lateral allows for intervention in both the motherbore and lateral at any time. A well completed with this multilateral technology recently required intervention for well logging and treatment to revive the well. Slickline runs were performed to gain access to the horizontal lateral, which included retrieval of an isolation sleeve and installation of a tubing exit whipstock (TEW) for lateral re-entry. Later, coiled tubing (CT) was run through the window into the lateral to perform intervention operations and revive the well. Upon completion of the intervention, the TEW was retrieved from the window, the isolation sleeve was reinstalled, and the revived well returned to production. Well intervention through this multilateral completion demonstrates the ease and efficiency of accessing both the vertical and horizontal lateral, without requiring a rig or completion retrieval.
This paper will highlight the multilateral completion technology for accessing both the laterals, including real-time monitoring capabilities that provide more reliable data to maximize the recovery and management of the reservoir, as well as perform effective intervention.
