Integrated Production Optimization Workflow Provides Robust Platform for Significant Oil Gain to a Mature Oilfield

Abstract

This paper demonstrates the production optimization methodology being used by Kuwait Oil Company to increase production in one of its giant and mature fields by 18% over 5.0 years. Production optimization is a continuous iterative process to improve production, especially in mature fields. The North Kuwait Redevelopment team has adopted an integrated enhanced and structured process to identify opportunities for production optimization with a pro-active approach focusing on flowing wells and rig-less interventions to tackle production challenges and achieve production targets Typical mature-field challenges are present. These include water flooding, produced water management, artificial lift, with more than 1000 (vertical, deviated and horizontal) active wells, coupled with high structure complexity and stratigraphic heterogeneity, tight sandstone and carbonate reservoirs, shortage of work-over rigs. These challenges make the field appropriate to apply the production optimization methodology outlined here. The Heterogeneity Index (HI) process is utilized to rapidly demonstrate production gain opportunities, for a giant mature North Kuwait Sabria field of approximately 1000 wells produce from different reservoirs. The HI process provided a quick screening method of identifying preliminary candidate wells with anomalous behavior (over/under performance) for further analysis and most importantly, provided the foundation for the overall structured production approach. The results from this screening tool were utilized to identify the families of type productivity problems at field and well levels with solution categories for production enhancement. Representative wells were selected for detailed diagnostics based on the relevance and size of productivity impact and the potential of its well deliverability. Once a few "top potential" wells were identified, production engineering workflows were implemented to assess and forecast the potential of production increase and to determine and evaluate the best intervention action. This production optimization workflow is done in a consistent cycled process considering the ageing condition of the mature field, and the aforementioned challenges. Approximately 35% of the wells have been selected for further analysis over multiple production optimization cycles spanning approximately 5.0 years. A detailed production engineering workflow provided recommendations of various remedial intervention solutions to improve well production potential via productivity enhancement, water shut-off/conformance, stimulation, additional and/or re-perforations, and Artificial lift optimization. Other advanced technologies were applied to improve various strategies, including completions, perforation, stimulation, and injection/production control. To date (Febrauary, 2018), recommendations for approximately 30% (300) wells have been executed, with a significant oil gain of approximately 18 % of the total field production.