oa Jurassic Carbonate Tight Gas in North Kuwait: Exploration through Initial Production

Kuwait Oil Company (KOC), as part of the strategy to meet the domestic gas demand, is currently<br>developing the six North Kuwait Jurassic age tight gas reservoirs. Till early 1990s majority of the<br>exploration and production activity in Kuwait was focused on the shallow conventional Cretaceous<br>targets. A paradigm shift in exploration activity with focus on unconventional reservoirs, driven by<br>detailed seismic studies and revised depositional models, led to the discovery of six North Kuwait<br>Jurassic gas fields. These reservoirs, Najmah-Sarjelu and Middle Marrat, are characterized by low<br>porosity (average < 5pu), low permeability (average <0.1mD) and in deep (> 13500f t depth) HP/HT<br>(average 11000psi/280F) sour conditions. Sub-vertical natural fractures are the main contributors for<br>production for the Najmah-Sarjelu reservoir. Though Dolomitization improved reservoir characteristics<br>of Middle Marrat in part of the area, natural fractures play a dominant role in aiding production from<br>this reservoir. A dual porosity Geocellular model, encompassing this large area (~1800sq km) having<br>large gross reservoir thickness (~2200ft), with limited 39 well control is built to understand the HCIP<br>and as an input for the simulation model. A detailed interpretation of log, core, and seismic data<br>helped in refining the depositional model. The Discrete Fracture Network (DFN) models are constrained<br>by seismic attributes for realistic fracture population in the inter-well space. This paper presents the<br>journey from exploration to early production with focus on challenges being faced and the mitigation<br>strategies adopted in modeling and developing these fields.