Peripheral water flooding has been the preferred pressure maintenance tool for many gulf carbonate reservoirs over the past 30 years. Due to uneven sweep and pressure distribution, this technique has given way to pattern floods in several gulf fields. As these new floods are established, it is important to understand the water saturation between wells to properly manage the sweep and recovery. In 2007, ADCO initiated water injection (WI) and WAG pilots to test the recovery strategy. The pilot employs advanced geophysical and modeling tools to measure formation properties at the wells and between wells; this paper discusses the WI pilot. Among the novel techniques applied is the crosswell electromagnetic method, which measures the interwell resistivity distribution between observation wells at the pilots. Interwell resistivity data can be used to infer the water saturation distribution because of the sharply different electrical resistivity between injected water and oil bearing reservoir rock. By allowing an evaluation of the water distribution long before the injected fronts reach producers or observers, a better and more rapid understanding of the pilot arises from the crosswell electromagnetic technique. In this paper, we briefly describe the pilot design, describe the detailed geological model and show results from the initial set of baseline and time lapse EM data sets from the water injection pilot. The images highlight the influence of background geological constraints on the flow. Introduction Applying peripheral water flooding for pressure maintenance was commenced after few years of the discovery of field A, a giant complex carbonate reservoir in the middle-east. Although this strategy has been successful, there is evidence of an uneven sweep due to reservoir complexity. These complications have led to the introduction of pattern-based flooding technology and the establishment of the water injection (WI) and WAG pilots in the underswept lower units of the reservoir. The benefits of pattern flooding are more efficient and faster recovery. The potential drawbacks are greater costs and higher local pressures which could induce uneven flows. Detailed pattern flood modeling helped develop an optimum strategy for maximizing reserves and production, especially in the lower two oil bearing units of the reservoir (Ref. 1). Consequently, WI pilot has been implemented in the lower units of the reservoir. A detailed multi-year and multi measurement monitoring plan has been established to determine the pilot performance which includes deep reading technologies like electromagnetic surveys. The main objectives of the WI pilot project are:determine sweep efficiency in the target reservoir units,qualitatively assess the impact of injected fluid fluxes vertically across low permeability sub-units within the reservoir, anddetermine pressure support due to pattern injection. The pilot will also address the issues of uneven sweep, bypassed oil, and residual oil saturation. The acquired field data will be used to calibrate the simulation model for production, injection, saturation and pressure data in order to design as an optimum field development scheme for the lower reservoir units in the southern part of the field. (Ref 2)

A super Giant field production sustainability is essential and has to be sustained for longer period of time, therefore different techniques have been introduced and tested to overcome the various reservoir issues. Gas Lift technique (GL) has been considered as one of the effective mitigation actions to reactive the dead wells, enhance recovery factor (RF) and accelerate the production from both technical and economical points of view. Prior the full field implementation, it was decided to select a GL Pilot for testing and data gathering, the planned GL Pilot consists of 10 wells which have been selected from various reservoir units and completions to analyze the differences in the performance. The selected Pilot wells were inactive prior to GL implementation (with no oil production) as per set strategy which calls for using of the GL system to reactive the dead wells only.The Pilot started production in November 2008 with almost a total oil production rate of 14 Mstb/d using GL system and the current average rates of the pilot (as of Jan. 2010) are as follow: average oil rate ~ 13,000 bbl/d, average water rate of ~ 19,000 bblw/d, average gross rate of 32,000 bbl/d and average W.C% ~ 60%. The pilot performance was achieved with total gas lift injection ~ 6 MMSCFD (which means 0.6 MMSCFD per well in average). The total oil recovered from the current GL pilot, during a period of one year (330 producing days) is 4.15 MM bbl, this can be roughly turned in to cash amount equal to $ 207.5 MM (assuming 50$/bbl).These resulted values from the GL wells have been surging up and down as a result of the optimization process in order to minimize the W.C% and increase the oil rate. Real Time Optimization (RTO) process is important and currently is ongoing (last stage) to be fully implemented to optimize especially the GL produced water (amount and treatment) in addition to the oil production. Gas quality, availability and conditions have been ensured with the current available field facilities.Pilot Modeling is vital to assess each well behavior, therefore every well has been modeled using Inflow/Outflow Software and pertaining data has been continuously validated and updated according to the production tests and actual findings. Different monitoring tools have been used such as RST, PLT and Gas Lift surveys to identify the actual well performance. The Pilot modeling results have been used as a guidance to predict the full field future GL performance.Generally, the Pilot results revealed the important questions and achieved the core objectives related the GL system for full field implementation.