For the last 30 years, wells in the field have been suffering from medium to high corrosion rates in both near surface and downhole components. Remedial measures had been implemented in order to restore Well Integrity with different techniques. Corrective actions aside, a strong preventive approach is needed to better understand the root causes of such corrosion rates and scenarios where the integrity of specific wells has been seriously compromised due to corrosion problems.Taking a step further and considering the big implications of new projects such as Artificial Islands project, where the company will be drilling & completing over 300 Extended Reach Drilling (ERD) wells, Well Integrity input as a discipline becomes critical in order to ensure previous problems will not be repeated and all lessons learned throughout the years will be wisely taken into consideration when designing a new well to remain integral during its whole expected life.Understanding of the current corrosion mechanisms in the field was the key to find not only solutions, but also, to create an approach aimed to improve the future completion for Island wells in terms of design, materials and many other factors.An extensive multidisciplinary approach was carried out in order to successfully complete a full study in one of the pilot wells completed with Inflow Control Devices (ICDs), which will be analyzed in detail in this paper, covering the following areas:i. Well design and configuration ii. Well monitoring and performance review iii. Well diagnosis and failure investigation iv. Post-Failure modelling and well prediction v. Preventive/Corrective actions for future wells. Corrosion management and prevention of scale deposits were the two main challenges encountered during this project, which was launched and completed with the main objective of evaluate and optimize the ICD completion design in one Maximum Reservoir Contact (MRC) pilot well in the field, the findings and lessons learnt were used to upgrade the current well design and improve the development plan for the field.

A modeling study was undertaken to optimize the subsurface development of a giant offshore oil field in the UAE, using the concept of artificial islands. The new development plan capitalized on many advantages of artificial island in terms of surface and subsurface flexibility [Ref.1]. The main objective of this paper is to present the dramatic changes in a field development plan (FDP) which have been achieved by incorporating the concept of Maximum Reservoir Contact (MRC) wells and Geologic Drainage Area (GDA) for development of reservoir G. This revised FDP was the result of evaluating various development options for reservoir G and incorporating learning from sector model through a workflow which was established for this purpose. In this paper, we describe multiple field development options which have been evaluated for reservoir G through full field modeling and sector model sensitivity studies. Recommendations are made for the optimal development plan. The recommended development plan (referred to as the Island Option) is tailored to the geologic description of the reservoir and uses 3 km maximum reservoir contact (MRC) wells in addition to shorter MRC wells, enabled by drilling wells from islands instead of conventional drilling and production towers ("WHPTs"). Key elements of the island development plan are that it:Is based on a variably spaced, line drive pattern floodHonors the reservoir geology and current oil saturation distributionUses ~3 km MRC wells with closer spacing (~0.5 to 1 km) in place of the current 500 m to 1 km WHPT wells in areas of the reservoir with low permeabilityUses ~1 km MRC wells with larger spacing (~1 to 1.5 km) in areas of the reservoir with high permeabilityPerforms better than the predecessor development plan (referred to as WHPT Option) in terms of plateau duration and ultimate recovery The recommended plan for reservoir G is the Island Option, which calls for drilling 79 new wells compared to the WHPT Option which would have required 140 new wells. The new wells in the island development plan are a mix of 3 km MRC wells, 1 km horizontal wells and vertical wells. The MRC wells are oriented in a northwest-southeast direction to be aligned with the predominant fault direction in the field, reducing the risk of poor areal sweep because of water breakthrough resulting from wells intersecting faults.

An integrated completion design modeling approach has been implemented for development wells in a giant offshore field to maximize asset value and recovery. The modeling approach enables the selection of lower completion inflow control devices and well path compartmentalization strategy for every well based on predefined criteria.The development of the field under consideration is progressing with a water flood recovery scheme that requires the use of new technologies to achieve higher oil recovery and controlled water production. Since the only contact with reservoir is the wellbore, efficient reservoir sweep and recovery can only be achieved by putting the right well equipment in the right location.In this paper, the design process which has been adopted for well completion design using Inflow Control Devices (ICDs) will be shared and explained. An interactive loop is used to optimize the number of ICDs and nozzle sizes using reservoir simulation coupled with specialized well and completion modeling software.A number of ICD well completion design examples are presented. From these examples, predefined design criteria are applied in an iterative manner targeting optimal sweep and maximum recovery as an objective function. The key criteria elements are:• Predicted water flow mechanism from nearby injectors into the well. • Reservoir pressure contrast along the well path and variation over time to account for additional pressure drop imposed by ICDs. • Permeability contrast along the well path. • Effect of nearby producers, if within the same drainage area.When concluding the detailed completion design, the outcome is shared with the Drilling operation team for fine-tuning, materials selection, materials procurement, and implementation. Further modeling work will be discussed covering the impact of the stimulation design resultant skin on predicted recoveries.

Modern well testing is marked by the introduction of pressure derivative in analyzing well test data. The improvement of exploiting the shape and the particular points of the pressure derivative curve made a great progress in reservoir characterization and development. In certain circumstances the quality of measured pressure data can be affected by extern or intern noises. Consequently, errors may be amplified while computing pressure derivative and the out put data of the well and the reservoir such as wellbore storage, flow regimes, reservoir permeability, boundary limits can be unreliable.This paper present a new method for reducing model error by adjusting the derivative pressure in cases of homogeneous and naturally fractured reservoirs. A WTS software is developed for providing permeability, skin factor and well bore storage for homogeneous reservoir and interporosity flow parameter and storage coefficient for naturally fractured reservoir as reliable as possible. PETROLEUM SOCIETY