Optimizing Route of Produced Water Disposal

Abstract This article presents a detailed concept selection study aimed at economically optimizing the disposal of produced water from high water cut and maturing oil reservoirs. The study is carried out on an existing oil production facility that has a built and operating network specifically for water disposal through water disposal wells (WDW). Given that forecasts indicate additional produced water will exceed the current network's capacity, this study was initiated to determine whether the existing base route of disposing of the water through disposal wells should be maintained or if alternative routes might be more economically attractive. To achieve this objective, a comprehensive analysis of key surface and subsurface factors was undertaken to assess the optimal operating conditions for disposal via water disposal wells. Additionally, hybrid and alternative disposal routes were thoroughly investigated to enhance both efficiency and cost-effectiveness in the process of water disposal. The concept development process began with a thorough evaluation of subsurface factors that affect water disposal through wells. This involved assessing the injectivity index, which quantifies the rate of water injection in relation to pressure, and evaluating the frequency of acid stimulation required to sustain well performance. Additionally, surface factors such as water quality and disposal pressure were scrutinized to understand their impact on the efficiency of water injection rates. The study explored two principal disposal routes: (1) complete disposal through water disposal wells and (2) a hybrid approach that integrates wells with various surface disposal methods. Surface disposal routes, including evaporation ponds and wetlands, were examined in detail to evaluate their feasibility and cost-effectiveness. By integrating both subsurface and surface considerations, the study provides a thorough analysis of how these factors interact to influence water disposal strategies. The findings offer valuable insights into optimizing water disposal practices within the oil and gas industry, underscoring the potential for enhanced economic outcomes and improved operational efficiency. This comprehensive overview delivers a holistic approach to produced water disposal, aiming to balance both surface and subsurface technical considerations to achieve economically optimal results.