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The Armatella Field in SE Sicily is structurally complex with two fractured, carbonate reservoirs containing heavy-oils, with the heavier hydrocarbon overlying the lighter one. One well has been drilled in the field – a vertical pilot completed with two opposite, stacking, open-hole horizontal drains. A complex compositional evolution of the fluids produced has been observed. A reservoir study integrating geophysics, geochemistry, petrophysics and reservoir engineering assessed the reservoir geometry and the field production behaviour. This allowed the identification of two different phases of hydrocarbon migration that were geologically constrained according to the structural evolution of SE Sicily. The 3D structural reconstruction of the field, built with a Shared Earth Model, was utilized as input to a 3D dual porosity numerical model. The dynamic simulation allowed identification of the drilling location of an additional non-conventional well aimed at draining undeveloped reserves. The study used advanced laboratory methodologies for fluid characterization, state-of-the-art methods for analysing the reservoir fracture network and properly designed modules for simulating non-conventional completions in a 3D dynamic model.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIn the past years technological advances in drilling and completion have provided the possibility of improving the reservoir productivity by resorting to new options such as multilateral wells and intelligent completions or a combination of both. However, some serious difficulties arise to simulate the performance of advanced wells as standard well models neglect friction effects along deviated drains and do not allow selective fluid flow control when bottom hole flow control devices are used. Some new simulation options have been recently developed that, reportedly, provide a thorough description of the local flowing conditions along the well and account for pressure losses along the wellbore and across any flow control device. The new simulation options were applied to simulate the performance of a dual opposed, stacked lateral well completed with bottom hole flow control devices draining an oil reservoir comprising two hydraulically separated pools. During the first years of production the two drains were initially left open hole. When water break through occurred and water production started to progressively increase, the possibility of adopting an intelligent completion to control fluid entry from each drain appeared very attractive to optimise oil production. Therefore, a 3D numerical model of the reservoir was set up. Once the calibration of the model was attained, the use of intelligent completions was simulated in an attempt to evaluate the reservoir performance when flow control was applied to each drain, and to determine the optimal well configuration to maximise productivity. Productivity forecast showed that intelligent systems allow both enhancement of oil production and dramatic reduction of water production compared to the case where conventional completions are adopted.

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