The Greater Burgan oilfield is the world's largest sandstone oilfield, it was discovered in 1938. It is located in southeastern Kuwait covering a surface area of about 800 square kilometers. It is ranked as the largest clastic reservoir in the world. The Greater Burgan oilfield comprises six main reservoir units, namely Wara (WAS), Mauddud limestone (MAS), Upper Burgan Sands (BGSU), Middle Burgan Sands (BGSM), Lower Burgan Sand 1 (BGSL1) and the Lower Burgan Sand 2 (BGSL2). The main focus of this study is the Wara reservoir.

The Wara reservoir was discovered as one separated producing reservoir from the Burgan reservoirs in 1948; it is highly heterogeneous and further divided into seven layers based on the petrophysical interpretation. Those seven layers are grouped as three zones based on their depositional environment, namely Wara Sand Upper (WASU), Wara Sand Middle (WASM) and Wara Sand Lower (WASL). Due to the heterogeneity and the lack of the pressure support, most part of the reservoir is not being produced; the Wara Pressure Maintenance Project (WPMP) is planned to drill massive numbers of producers and injectors.

In order to plan the wells in a way that maximizes the productivity and optimizes the economy; the Well Type Modeling study was initiated to study the effect of different well type angles on the oil recovery. The common belief is that the horizontal and slanted wells are better than those of the vertical wells, as they have better exposure to a reservoir. In a homogenous reservoir system it is certain that the horizontal and slanted wells have higher productivities; however for the heterogeneous and layered Wara reservoir the advantage of the horizontal and slanted wells are not guaranteed.

This comprehensive study was conducted in three selected sectors in the field. Different scenarios represent different well types, patterns, well spacing, well constraints, oil types and other sensitivities were implemented and the economic revenue and recovery factor were evaluated. The results of this study will guide on the future planned massive drilling plan for the WPMP and the infill drilling.

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