Computer-Aided Design for a Multilateral Well Completion in a Stacked Reservoir

Over the years, multilateral well technology has been one of the most rapidly evolving and widely utilized production technologies for new and maturing reservoirs. Multilateral wells have the potential for reservoir productivity improvement. The characteristics used to evaluate multilateral well completion are connectivity, isolation, and accessibility. All these focus on the completion design of the main bore, lateral bores, and junctions that connect the lateral and main bores. Hence, one of the factors to consider in designing multilateral wells is the junction type, which depends on the required degree of mechanical integrity and pressure integrity at each lateral. Previous studies establish that the lateral junctions are a critical element of multilateral completions and can fail under formation stresses, temperature-induced forces, and differential pressures during production. Thus, the reliability of a multilateral completion design is the ability to construct and complete the multilateral junction successfully. The Technology Advancement of Multilaterals (TAML) has categorized the distinct types of multilateral junctions based on support and hydraulic integrity provided at the junction. The objectives of this paper are: (1) to provide a detailed discussion on each classification level and the conditions in which they are applicable, (2) to present a conceptually digitized application of a multilateral well on a stacked reservoir XXXX in a Niger Delta field using SEPAL software. To achieve the latter goal, after a preliminary and detailed casing design, we applied the SEPAL software to design and digitize the proposed multilateral well schematics for the stacked reservoir. From the analysis, a multilateral level 5 junction was selected to overcome specific problems (e.g., wellbore collapse) due to the unconsolidated sands of the reservoir in the field of interest.