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Optimal exploitation of hydrocarbon reservoirs has always been a challenge due to uncertainties posed by subsurface heterogeneities that are often not factored into field development plans. Secondary and tertiary recovery mechanisms, such as waterflooding and enhanced oil recovery (EOR), are used to enhance the oilfield recovery beyond primary recovery. However, as the field development transitions to secondary/tertiary mechanisms, the challenges in monitoring these mechanisms further increase the uncertainty in field development. If these uncertainties are not reduced or incorporated properly, the field development may easily become uneconomic. This work presents a workflow that addresses the limitation of regular waterflood surveillance while characterizing the reservoir for optimal exploitation. The current technologies for waterflood surveillance are limited either to local surveillance methods, such as tracers, crosswell seismic and crosswell electromagnetics (EM), or to uncalibrated global realizations, such as full-field streamline simulation, with no validation between the wells (It is to be noted that a full-field reservoir simulation calibrated with production-injection data in defined time-interval is stated as a global-surveillance method in this paper). This workflow devises integration of an effective local waterflood monitoring method, crosswell EM, and a global waterflood modeling method, streamline simulation. The process of validating the parameters of a geological model and a dynamic model with time-lapse crosswell EM data significantly reduces reservoir characterization uncertainty and helps in the preparation of a precise dynamic model.

Borehole images have been widely used in industry for almost three decades for different geological and petrophysical applications; though these logs were often limited in application in the wells drilled with oil-base mud (OBM) due to resolution and coverage constraints against the downhole environment. Recent advances in technology helped address this issue with wireline logging; however, the logging-while-drilling (LWD) capabilities for high resolution borehole images in OBM remained limited thereby limiting any real-time applications of this data. The new innovative multi-measurement LWD imager provides game-changing enabler for wide-scale comprehensive solutions from drilling-efficiency till field development. Singular image acquisition for subtle features at high resolution could often miss out on a lot of important events, thereby constraining the optimal characterization of sub-surface and downhole conditions. To properly understand, characterize and demystify the sub-surface, Industry's first multi-measurement imager was developed with high resolution capabilities in OBM; with ultrasonic and electromagnetic measurements physics. Ultrasonic and Electromagnetic measurements are made at multiple frequencies by multiple sensors to ensure that the features on borehole wall are observed and resolved, both. The complementing nature of these technologies provide far better application capabilities, with multiple full-bore images being acquired simultaneously for apparent resistivity, amplitude and transit time by multiple sensors to overcome downhole operational challenges and variability of formation response without introducing complexity to the drilling bottom-hole assembly (BHA). The apparent resistivity images from electromagnetic measurements provide rich information of the sedimentological, diagenetic and structural features while the ultrasonic images are more sensitive to the near wellbore fracture, drilling induced features and borehole conditions. Availability of the multiple measurements in real-time and relevant time lends the borehole image data for various applications, enabling drilling optimization, smoother and efficient operations and detailed geological characterization. Such comprehensive applications were not available earlier for wells drilled with OBM or any non-conductive mud.

Wireline Formation Testers have been used in the petroleum industry for decades to provide accurate formation pressure measurements and fluids properties with wide range of applications through all the stages of in the life of a reservoir; exploration,appraisal,development,production and injection. Wireline formation testing done mostly using cable-operated tester and sampling tool anchored at depth while reservoir communication is established through one or more pressure and sampling probes .Traditionally, the selection of the formation pressure and sampling points rely on conventional resistivity and porosity logs. These logs often fail to produce optimal results because of the complex nature of the dual-porosity carbonates in South Iraq. The work illustrated in this paper tried to optimize the selection of formation pressure and sampling points by the utilization of high-resolution azimuthal log measurements such as borehole images. The use of a high-resolution electrical borehole image log helps place the tool probes at optimum depth locations and pinpoint the "sweet spots" suitable to achieve the best results of formation pressure and sampling measurements.