Mitigation of Structural Uncertainty in High Angled Dipping Up Middle MarratReservoirs With the Help of Deep Electro-Magnetic Inversion GeosteeringTechnique,Calibrating With Seismic Data-A Case Study,Umm Gudair Field,West Kuwait

摘要

The Umm Gudair field is an elongated doubly plunging anticline which bifurcates into two branches NSelongated West UG and the NE-SW elongated East UG structures with a broad saddle in between Fig1A &1B.West Umm Gudair structure was formed during the Jurassic time and become reactivated in Cretaceousand Tertiary times.East Umm Gudair was formed during Cretaceous as evident from the thicker depositionof overlying Gotnia sediments and its unique fold geometry.A total of 28 wells targeting Najmah-Sargelu (NJ/SR) & Marrat reservoirs of Jurassic have been drilledso far in this field including one deep well in South UG in Divided Zone The Marrat Formation in Umm Gudair field is conventional reservoir with 800ft to 1000ft thick sequencecomprising limestone,dolomitic limestone and argillaceous limestone with minor shale and anhydrite.TheJurassic sequence in Kuwait oil fields starts from around 12000ft and is marked by an increase in formationpressure and temperature.Above this lies the Cretaceous sequence where most of the oil field developmentworks have been concentrated in the past.In the last two decades field development has extended to theJurassic sequence to meet up with increasing production demands.The Jurassic sequence is marked by aseries of high pressure and high temperature formations with presence of natural fractures.