The Middle Cretaceous Burgan reservoir in Minagish Field exhibits variable depositional clastic settings ranging from "Fluvial", "Fluvio-tidaT to "tidal wave sands". The sand bodies of Upper Burgan reservoir are highly heterogeneous in terms of the stratigraphic architecture implying extensive lateral facies variations, stacked sand bodies and varying petrophysical properties. Modeling the target sand channels and optimizing subsurface well trajectory with maximum reservoir contact requires "high resolution" geological and seismic data integration in order to minimize uncertainties related to correlations of timeline surfaces, channels geometries and sub-seismic fault network. Since traditional logs could not capture the textural differences characterizing the reservoir zones, Real-time formation evaluation and geosteering challenges addressed to ensure the successful drilling and completion of level-4 "Multi-lateral" producers. A combination of the latest advanced geo-steering technology used in this well including Rotary Steerable, Distance to Boundary and Sourceless petrophysical evaluation while drilling. The uncertainties in the geostatistical models were further reduced while drilling the first lateral section (LAT-0) by deploying extra deep azimuthal resistivity measurements. It has a higher precision and accuracy to consistently mapping the rise in OWC due to production operations with depth of detection up to 100 feet TVD above and below the well path and maintaining a standoff from the top of onset transgression undulating surface with poor sand facies. The resultant mapping window provided accurate guides to update the geo-models. The formation evaluation along with borehole imaging and geo-correlation assisted in identifying a fault having a great impact on well positioning of the upper lateral due to a high amount of throw fault with significant formation dip changes. This is in turn eliminating risks of geosteering in such a complex heterogeneous reservoir. The integrated approach utilizing geological, seismic, petrophysical and geosteering data provided better understanding for well positioning while drilling and achieving the MRC without exiting the sweet zones of targeted upper and lower Burgan sandstone in Minagish field and enhanced water free oil production.

The Minagish Oolite is one of the main reservoirs in the Minagish Field, Southwest Kuwait. The field is a large 4-way dip closure anticline structure, covering an area of about 90 square kilometers and with around 900feet of carbonates of the Minagish formation. The Middle Minagish member is the main reservoir, consisting of oolitic limestone with high permeability in the range of 10 to 1000 mD. The Lower Minagish member contains dense fine grained wackestones to packstones with low permeability. The Middle Minagish and Lower Minagish oil reservoirs contain highly undersaturated oil with API gravities of 28-34 °API and share a common FWL at 9950feet TVDSS. The dynamic model built along with time lapsed historical (production/injection) and well surveillance (PLT, TDT, well test) data are used for tracking the movement of injected water and gas, monitoring fluid contacts and changes in saturation with time, optimizing production and planning of new wells. Nonetheless, due high density of producers existing around the field causes mutual interference amongst the neighboring wells and surprises arise while drilling new wells. Real-time Geochemical analysis on elemental and mineral concentrations within drill cuttings/core chips, integrated with advanced mud gas data, can provide an additional analytical dataset to assess reservoir depletion and water encroachment. This advanced surface logging technology can give a better indication on water bearing zones and water encroachment when MWD/WL logs have resolution issues. When geochemical and mud gas proxies are integrated with other data sets (viz. logs, and dynamic data), they provide a better control on lithological changes and water bearing zones, throughout the entire reservoir. Integrated geochemical and advance mud gas analysis in depleted Minagish reservoir has helped to confirm zones of interest and to determine leading edge of water aquifer. Ultimately this enabled for a unique completion design. The well MN-X, object of the study, represents a valuable case where it has been possible to identify water encroachment through geochemical proxies, aiding the completion strategy.