Surmounting The Challenges Leads To Discovery Of New Field In Deep Jurassic Formation: A Case Study

This paper shares and discusses the challenges faced and activities that led to a significant discovery in a deep carbonate reservoir. It covers the successful well-testing design as well as the methods and procedures adopted to complete short term test of this well safely. A new structure in the state of Kuwait was identified for drilling the first exploratory well targeted at deeper Jurassic formations. Adjacent fields to this structure are HPHT naturally fractured reservoirs and fluids are sour in nature. The target well was sidetracked twice with two different kick-off points while drilling the deep formations due to well control problems. Deep formations in combination with HPHT and sour environment created unusual challenges while testing several zones in this well. Based on past experience, a simple test string assembly suitable for HPHT and sour environment was selected for this well. Perforating using deep penetration TCP guns, stimulation with Breakdown acid followed by emulsified acid and testing with Drill Stem Testing (DST) techniques were applied for evaluating the deep formations. During short term testing of second zone, gun hanger has moved upward by about 900 feet and plugged 5” production liner top preventing any flow/access from the zone below. Though this zone produced hydrocarbon, full potential could not be established due to plugging. The last zone was successfully tested and produced significant amount of gas and 44.5o API oil with 1% H2S. Meticulous planning and testing strategies could overcome many challenges to discover commercial quantities of hydrocarbon from new field. This new discovery adds significant hydrocarbon reserves and put a new field on the map of the state of Kuwait. Based on the commercial success in this well, further exploration and development activities are being planned to focus on the same structure.