The study covers a giant oil field situated in Iraq. M formation is the major producing reservoir in the field, and is characterized by a complex heterogeneous carbonate system. Reservoir rock typing in carbonates is a critical process by which geological lithofacies are characterized by their dynamic behavior, which is needed for better reservoir characterization required for reservoir modelling and numerical simulation to optimize development plans and maximize oil recovery. The operator company has conducted a comprehensive reservoir characterization study for M reservoir involving, routine core analysis, SCAL, Static and Dynamic rock typing studies in M formation, alongwith routine geological and petrophysical analysis. Thomeer methodology was used for Static Rock Typing analysis, utilizing the extensive available Mercury Injection Capillary Pressure Data (MICP) to capture the complexity of the M carbonate reservoir, and the Thomeer parameters (G – shape factor, Bv – Bulk Volume and Pd – entry pressure) were derived for every pore mode of these selected MICP plugs. Five pore geometry groups were proposed based on modes identified in the PTR frequency distribution, then created five equivalent Static ‘rock-types’. These were given further reservoir context through integration with Petrography, Sedimentology and NMR data available from core and logs. Due to the complex nature of heterogeneous carbonate formation of M, the five major static rock types were further characterized by their dynamic behavior to reflect the interaction between the rock lithofacies and reservoir fluids. While porosity, permeability and pore size distribution characterize the rock texture, SCAL parameters, capillary pressure, relative permeability and wettability will capture rock-fluid interaction and will impact oil recovery from such complex heterogeneous system. Different methods were tried to correlate dynamic rock types in M formation including Classical rock typing methods based on logarithmic regression of permeability versus porosity cross plots, as well as Flow Zone Index (FZI) and Reservoir Quality Index (RQI) methods. This was followed by applying Winland method for dynamic rock typing characterization. This paper describes the successful workflow adopted in the study to define the Dynamic rock types for M formation based on Winland methodology, where a total of 16 core plug samples were selected using CT scans screening (2 plug samples selected from each of the major rock types RT) for Reservoir Conditions relative permeability testing as well as 4 samples were earmarked for ambient condition relative permeability measurements and further 4 plug samples were selected for wettability and capillary pressure testing covering all the major types. The Winland R35 methodology [1] was applied on the selected samples in order to verify if any of the core samples shifted from the previously defined static rock types. The new porosity and permeability and SCAL relative permeability and capillary pressure measurements for the selected samples were used as part of the workflow to calculate Winland R35 algorithm, then plotted to derive and characterize the new dynamic rock types for M formation in the field

This paper discusses one of the major conflicts between humans and the wild, natural life as portrayed in the Sumerian Epic of Gilgamesh, the earliest surviving great literary work of Mesopotamia. This epic is a prototypical, original narrative about the difficulties which the human groupings face in their confrontation with Nature. The text commences with a description of Uruk city and the wall surrounding it, built to protect the cultural against the natural. There are three protectors seen in the Epic: Gilgamesh, the protector of Culture; Enkidu, the protector of Nature first, the enemy of Nature afterwards; Humbaba, the protector of Nature per se. The lack of harmony among the three conflicting powers sparks the continuous tensions in Gilgamesh. The turn ing point in the Epic occurs when Enkidu joins forces with Gilgamesh in order to shield their culture by cutting down the Cedar forest. Ecocide is committed only after Endiku and Gilgamesh ally with the god of the Sun, Shamsh, in order to be spared the retaliation of nature as represented in Humbaba. But Gilgamesh will face the dark destiny of Nature's retaliation in an unexpected manner. This retaliation will be in the form of Nature's refusal to grant him immortality that he aspired for and sought for day and night in the last part of his life. Article Info

Understanding the hydraulic properties of reservoir rocks is crucial for estimating reserves or managing storage and production of a reservoir. In reservoirs containing complex carbonates, rock-typing methodologies that recognize multimodal porosity have been widely used. A new rock-typing workflow based upon Thomeer-buoyancy modelling is presented, with proven application in Middle Eastern carbonate reservoirs where multimodal porosity is observed. Porosity reflects the total pore volume of the rock, but fluid transport within the media rock unit is dominated by the fractional pore volume connected to the largest pore throat system. The mercury intrusion capillary pressure (MICP) experiment alone provides insight into the connected porosity and permeability volumes. In addition, the MICP experiment establishes the relationship between the vertical saturation profile of the wetting and non-wetting fluid phases. A workflow that captures the buoyancy of the fluids (saturation-height) alongside this pore volume complexity can then provide insight into the pore geometry, saturation distribution and permeability of the investigated reservoir volume. This workflow is distinctive because it integrates reservoir physics with new analytic approaches that include a routine conversion of properties from ambient to reservoir conditions, a fully automated Thomeer deconvolution of mercury injection experiments (THOPAL) and a Thomeer-buoyancy analytical solver for properties estimation in the log domain. The solutions provided comprise continuous magnitude and category estimations of 1) permeability at reservoir conditions and Thomeer coefficients (G,Pd and Bv), 2) statistical uncertainties of the previous, 3) continuous scalar results in the hydrocarbon column including reservoir capillary pressure, bulk volume oil and Sw as well as probabilistic pore geometry grouping. Two case studies are presented to demonstrate the application to wellbores within the investigated Middle Eastern carbonate reservoirs.

This reference is for an abstract only. A full paper was not submitted for this conference. Abstract Maximization of recovery from multilayered, viscous and highly heterogeneous oil fields is a challenging task for operators. Heglig oil field is located in Muglad basin of Sudan wherein oil accumulation is found in multiple layers of late cretaceous deposits. The formations are heterogeneous, unconsolidated with higher viscosity and strong aquifer support. Some formations are tighter too. Field was initially developed with commingly completed vertical wells with a wider well spacing. ESP and PCP are in application for lifting the oil. Current development & production strategies and concepts implemented in the field resulted into exponential rise of water cut which reached to 90% within 10 years of production. This behavior is resulting into sharp decline of oil production and causing significant bypassed oil. This paper discusses about the midcourse correction and modification of the exploitation strategy of the field by changing the completion strategy and targeting the bypassed oil by placing the horizontal wells of optimal drainhole lengths. Accordingly, reservoir re-development plan adopted drilling of horizontal wells with suitable artificial lift techniques as one of the IOR option for maximizing well productivity in this viscous oil field. Updated static and dynamic models generated for diagnosing the bypassing of oil and saturation distribution for identifying the suitability of the locations. More than a dozen horizontal wells were drilled during rejuvenation phase which contributed remarkably in oil production, generally 2–3 folds compared to current vertical wells production. Controlled well production limiting to 1000 bopd/well by optimizing the drawdown and pump off take resulted into sustained production from the wells and controlling water cut below 40% after a year of production. The paper also illustrates how integration of different disciplines with focused efforts led to successful rejuvenation of the viscous oil field with proper well placement and sand & water control.

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