In recent years, North Kuwait has implemented advanced drilling practices by sidetracking existing wells and drilling long horizontal sections through the reservoir, which are completed with smart completions. These often include up to 20 stages, each of which is isolated using swellable packers. Management of production from these long horizontal sections through these complex completions is highly cost-sensitive and maintaining an optimum production rate is key to the economic success of these type of wells, especially in the current low oil price environment.
In this case study the well was completed with 18 compartments with ICD's/sand screens and each isolated with swell packers(Fig-3). Production decline was dramatic and in three months since bringing the well on production, the gross production decreased by 50%. Quick diagnosis of the problem was crucial to understand the decline mechanism especially the production from each compartment along the horizontal section, determine what key operational steps could be taken to improve the production and then implement this as soon as possible.
Survey was conducted using memory logging tools, High Precision Temperature and Spectral Noise Logging (HPT-SNL), which is a unique data collection and reservoir analysis service, to evaluate the contributing segments along the horizontal lateral. These tools were conveyed on coiled tubing, and the well was kept producing during the 2-day logging programto prevent any production deferment. A detailed reservoir analysis was completed, with the conclusion that out of the 18 oil production intervals, a total of 5 were either poor contributors or not contributing to flow. Based on the results, a stimulation program was designed and implemented targeting these 5 non-productive ICD intervals. Following the stimulation program, the well was re-tested with significant increase in production. A sustained incremental oil production of 180 BOPD was achieved. Identifying the stimulation opportunity in thisunder-performing low rate horizontal well with smart completion and ESP assisted production and implementing the stimulation has been achived riglessly with the use of HPT/SNL tool. Critical to this identification process, was the installation of Y-tool to facilitate deployment of the Logging suite.
Additional benefits gained from this data acquisition were the ability to selectively target zones for stimulation, instead of treating the entire reservoir. Also, the entire operation was conducted with minimum well shut in time. The highlights of the whole operation wereminimum production deferment, major operational cost savings and ultimately return the well to an increased level of production.