The UAE field has many thin multilayered carbonate reservoirs. Production from thse thin reservoirs are primarily supported by water injection. Reservoir properties, such as permeability, pore pressure, and water saturation, vary significantly both across the field geographically and within the different layers. Recently a study has been done to drill and maximize reservoir contact via ERD wells. To reduce costs and improve recovery, further development of the plan is to use wells drilled with throws greater than 15,000 ft and measured depths greater than 20,000 ft with some wells exceeding 35,000 ft. Long horizontals provide many benefits including enhanced access to offshore reserves, optimized productivity, reduced capital expenditure, and a minimized environmental impact With these benefits come challenges, accessibility for intervention operations being the most prevalent. Many factors affect the accessibility and intervention capabilities in ERD wells. Completion ID restrictions play a critical role in the equipment availability and selection. Once equipment is selected the leading principles used for improved access in ERD applications are: Increasing pipe bending stiffness to postpone helical buckling Reducing Normal Force between the CT wellbore Reducing Friction Coefficient Adding Axial Forces ERD applications and accessibility for interventions have been an ongoing challenge on how to properly model and predict the reach of CT in varying environments. The two pilot wells covered in this paper allowed for an array of information to be collected as the trajectories were very similar but the wells themselves were very unique. One well was a producer while the other was an injector. One well was completed with 13% Chromium and the other with conventional tubing. In this paper we will cover the above topics in more detail to clearly outline the challenges of ERD operations and the methods to overcome them. It will be clearly outline how these methods were used on two ERD pilot wells in UAE with the supporting actual operational data. These wells and lessons learned will pave the way for future ERD operations planned in both offshore and island based offshore UAE pilot projects.

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.

In recent years, a major Abu Dhabi offshore operating company has shifted towards utilizing Maximum Reservoir Contact (MRC) wells to improve oil production and long-term oil recovery. The initial MRC pilots demonstrated the importance of designing the well and completion to facilitate intervention and stimulation. Coiled tubing stimulation methods applied in these first wells were able to meet the objective by significantly improving overall oil production and water injection. However, as we move into tighter formations and longer wells the efficacy of coiled tubing is significantly reduced by limited accessibility and restrictions on the rate. The MRC strategy is being implemented in Reservoir II which is the largest reservoir in terms of Oil in-place. Reservoir II is a thick multilayered limestone reservoir characterized by its low permeability. This low permeability becomes more pronounced as one moves from the crest of the field to the periphery of the field. In such tight reservoirs (Reservoir II), conventional techniques may yield lower than expected production results. In an effort to improve production and ultimate recovery, a new stimulation and completion strategy is required that improves contact with the reservoir beyond the wellbore. In this paper we will discuss the design and implementation of a new technique intended to improve the production and recovery from tight reservoirs. This technique combines a fit-for-purpose limited entry type completion with high rate acid stimulation. Pre- and post-production comparisons demonstrate a substantial production increase and uniform contribution along the extended horizontal interval. We will review the design approach, job execution and evaluation of pre- and post-production performance. We highlight key technical challenges and risks encountered during the preparation, design, execution and evaluation stages of this operation and discuss how these were overcome and mitigated for the improvement and optimization of future MRC wells.

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