A dual-reservoir completion using Intelligent Well system together with an electrical submersible pump (ESP) in a high-rate well was recently deployed in one of the large carbonate fields in Saudi Arabia. The well was equipped with ESP to provide artificial lift to pump the oil to a centralized processing facility that is far a way from the well through a 2-zone "Smart" well completion, which remotely controls fluid inflow from each of the two laterals. This completion enables commingled production from two reservoirs while balancing flow contribution from each reservoir and avoiding cross-flow from one reservoir into the other. Commingled production from stacked reservoirs in the same field, or a single reservoir with multiple pay intervals, has many benefits during the development of a field - higher production rates per well, cost savings from reduction in the total number of development wells, flexibility in locating surface facilities as a result of minimal footprint, etc., Wide variation in reservoir properties, coupled with existence of natural fractures within an active waterflood environment in this case, prompted adoption of Intelligent Well technology to control fluid withdrawal and enhance waterflood front conformance. Additionally, there was a need to use proven conventional ESP system to lift the expected high production rates from the two prolific reservoirs. The new completion uses a re-designed downhole hydraulic disconnect tool with an integral anchor assembly, instead of other systems that have been used in the industry in the past, to connect the upper completion incorporating the ESP system with the lower completion that incorporates the Intelligent Well completion. Thus, ESP workover can be performed without the need to retrieve the Intelligent Well completion. This integrated system has enabled the two producing reservoirs to be commingled successfully and has provided the flexibility to control inflow from each reservoir in the future as the flow regimes change. This paper describes the equipment selection process, completion equipment, planning and deployment procedures of the Intelligent Well completion. Economic drivers for this robust completion as well as the reservoir management implications of successful deployment in this test case well and future expansion across the entire field are also discussed. Introduction The dual-lateral dual-reservoir well was drilled recently and completed in one of the largest multi-pay fields in Saudi Arabia. The field has several stacked oil-bearing reservoirs, which call for commingling production from some of these reservoirs to optimize field development. Additionally, pressure maintenance strategy requires the use of water injection to supplement reservoir energy for commercial exploitation. Fractures have been identified in many of these reservoirs from extensive resistivity and acoustic image logs ran across the field, as well as from the dynamic data gathered during past production periods. Small and large scale fractures present in these reservoirs are suspected to be conduits for the communication between the two reservoirs shown in Figure 1, which are separated by a thick section of fractured non-reservoir rock. Detailed review of historic pressure data shows synchronized pressure histories for these two reservoirs during past reservoir depletion, which was more concentrated at the crest and western parts of the field. This pressure performance suggests that the two reservoirs are connected hydrodynamically. Logs from both reservoirs also show concentration of fracture clusters at the crestal area and western parts of these reservoirs.

This paper describes the mega application of I-Field concept in Khurais Increment, the world's largest oil increment development in history. The field was developed to be fully intelligent from day one, thus, I-field infrastructure was part of the initial development plan and investment. Leveraging experience and lessons learned from previous I-Fields, and utilizing advances in technology, this application has better surveillance, higher reliability, and more utilities for end-users to manage and translate data into actionable information.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis article discusses the upstream development of Khurais field, referred to here interchangeably as the Khurais complex, consisting of several fields and reservoirs with a capacity of 1.2 million barrels per day (MMBPD) of Arabian Light crude. It describes the planning, execution and leveraging of technologies coupled with best industry practices to deliver the target rate while reducing the unit development cost, increasing the well productivities and expanding the reserves base. At the beginning of the project, a high resolution 3D seismic program was successfully performed to characterize the reservoir structure and geological features. Coupled with vertical-horizontal delineation wells, additional reserves were delineated and added to the development. To reduce the unit development cost, this article will show that the project utilizes a complex well architecture with a combination of maximum reservoir contact (MRC), multilateral, and horizontal wells, as well as smart completion (SC), smart electrical submersible pump (ESP), and passive inflow control devices to achieve and sustain the target rates. The development also sets the stage for technology leveraging in the future by drilling wells with large wellbores, allowing flexibility for the next-generation of complex well architecture while pursuing fit-for-purpose technologies through joint ventures and Saudi Aramco's Exploration and Petroleum Engineering Center -Advanced Research Center (EXPEC ARC).

A field-wide interference test was recently conducted to delineate the hydraulic communication between two large carbonate reservoirs separated by a thick non-reservoir formation. The reservoirs were newly developed with peripheral water injection for pressure support. This initial development stage provided an opportunity to take advantage of the undisturbed state of the two reservoirs during field commissioning to conduct this interference test prior to production. The injection start-up was, therefore, designed to inject into one reservoir while monitoring pressures at various parts of the other reservoir. Several observation wells across the field were designated to record the pressure changes during the initial water injection stage to provide the field coverage. The injection rates were also closely monitored and modified throughout the test period to record the rate of pressure change in the observation wells.The field was developed with the state-of-the-art permanent downhole monitoring systems (PDHMS) which provided the means for comprehensive monitoring of this field-wide interference test. The test showed some interesting findings within the reservoirs themselves, areas of communication were indentified and the extent of the lateral connectivity was observed. Additionally, the dynamic data acquired during this interference test will complement the static data for building improved geological and engineering models.This paper describes the test design, implementation and presents the results and findings. The test was concluded but monitoring is continuing utilizing the intelligent field (I-field) infrastructure and the results will, in future, be incorporated into reservoir simulation models for production/injection strategy optimization and accurate field performance forecasting. OTC 20571opportunity of the undisturbed state of the reservoirs, utilizing the readily available injection system, to conduct the test. The enabler was the leading-edge technologies implemented in the development.The following conclusions are drawn from the results of this field-wide test:• In addition to the central part of the field where the communication was discovered in the past, pressure communication between these two reservoirs was also seen at the southern end of the field, as this could be detected during the relatively short period of this test. • No significant pressure increase was seen in the east side suggesting no communication or very weak channels of communication in that area. • The degree of inter-reservoir communication at various parts of the field was assessed using the interference test results.With the conclusion of this field-wide interference test, the results will be used to adjust production/injection plans in both reservoirs in order to maximize hydrocarbon recovery. The potential risk of water encroachment from Reservoir B into Reservoir A will be minimized by this knowledge of more areas of communication.

The paper discusses the upstream development of Khurais field, referred to here interchangeably as Khurais Oil Complex, consisting of several fields and reservoirs to a capacity of 1.2 MMBPD of Arabian Light crude. It describes the planning, execution and leveraging of technologies coupled with best industry practices to deliver the target rate while reducing the unit development cost, increasing the well productivities and expanding the reserves base. At the beginning of the project, a high resolution 3D seismic program was successfully performed to characterize the reservoir structure and geological features. Coupled with vertical-horizontal delineation wells, additional reserves were delineated and added to the development. To reduce the unit development cost, the paper shows that the project utilizes a complex well architecture with combination of maximum reservoir contact (MRC), multi-lateral, and horizontal wells as well as Smart completion, Smart ESP, and passive inflow control device to achieve and sustain the target rates. The development also sets the stage for technology leveraging in the future by drilling wells with large wellbores, allowing flexibility for the next generation complex well architecture while pursuing fit-for-purpose technologies through joint ventures and Saudi Aramco Advance Research Center. The paper illustrates that the Khurais development is unique not only in terms of its size but also in terms of special technology applications and its complexity with respect to development of multiple fields and reservoirs with proper utilization of many complementing technologies. Through Saudi Aramco best practices, all of these are part of the development plan which utilizes applications of Advanced Mathematical Models in the form of Multi-Objective Function and probabilistic modeling techniques such as Experimental Design and Monte Carlo simulations. The development plan mitigates the development risk and optimizes oil off-take from different reservoirs and areas with respect to well placement, ESP design, depletion rates, injection production ratio, number of injectors and producers, pressure support, sweep efficiency, flood front conformance and oil recovery. The best practices also include real-time geosteering to ensure the horizontal laterals are directed through the best pay possible. The efforts have paid off as field tests of the producers, at the time the paper was written, show three to five times productivity improvement compared to existing vertical wells in the fields. The development also goes beyond the initial stage of the production as Khurais is the company flagship for I-field technologies in real-time data gathering, transmission and operation remote controlling to enable continuous monitoring and optimization of the field development and reservoir performance.