Surpassing the Challenges of CT Interventions in a Trilateral Extended Reach Well in the Arabian Gulf

Abstract

The oil industry in the UAE is striving to advance both onshore and offshore operations to address technological challenges that will allow for increased oil production in a safe and efficient manner. Offshore, artificial islands are being built for the purpose of accommodating up to 300 wellheads on a single island, with the wells themselves comprising multiple, extended-reach horizontal laterals. These ground breaking projects present new and exciting challenges for coiled tubing (CT) interventions, which require extensive planning and the use of innovative technologies.Specific challenges were identified during the design phase of intervening on a trilateral, extended reach well and applying several technologies enabled us to overcome these challenges to allow successful execution of a stimulation treatment on the well. Techniques used included accessibility modelling and CT string selection to achieve maximum reach.The methodology used and the testing conducted were designed to ensure that the multicomponent CT bottomhole assembly (BHA) allowed for selective engagement of each lateral and subsequent horizontal accessibility of each extended-reach lateral. Operations were performed in the context of the completion restrictions, diameter of the openhole and cased-hole laterals, and the requirement to pump large volume acid treatments. Each of these factors added a layer of complexity to the final CT BHA selection and setup, which had to operate within a limited range of activation pressures and rates.Finally, the lessons learned during the execution phase have been captured and recommendations formulated for moving forward with CT intervention in similar types of multilateral and extended reach wells. These lessons contribute to subsequent studies of maximum reservoir contact wells and form the basis of future development and intervention plans for the offshore and islands projects in the UAE.