The Shuaiba formation is a highly fractured limestone reservoir. The use of conventional overbalanced drilling technology in this formation usually results in the complete loss of drilling fluids to the formation. These losses cause drilling problems and results in the masking of the potential for hydrocarbon production. Underbalanced Drilling Technology was proposed as an alternative drilling method in order to evaluate the Shuaiba formation for producible hydrocarbons while simultaneously eliminating fluid loss to the formation and improving drilling performance.
The Shuaiba formation was successfully drilled underbalanced without any fluid loss during the drilling phase and a successful evaluation of the formation for hydrocarbons was completed for the first time. A multidisciplinary team contributed to the engineering, planning and execution of the first underbalanced drilling operation in Kuwait. This paper highlights the key factors in the underbalanced drilling design phase and the operational results of the first well drilled in Kuwait using underbalanced drilling technology.