A cost-effective water management strategy for the thermal development should ensure the availability of right quality and quantity of water during the lifetime of the field. This paper presents an actual case for field water management, which includes availability, use, re-use and safe disposal of both source and effluent water.
Thermal projects are notorious for their large volume of produced water through the life of the field. While treatment of produced water is a major issue; in a country like Kuwait where water is scarce, part of the produced water need to be recycled and re-used for steam generation. The methods and procedure followed are based on the practices used in the current Large Scale Thermal Pilots (LSTPs). The process involves field observations and performance, facility set-up and limitations, technical analysis and mitigation plan; so as to reach to an efficient water management plan and deliver better quality water.
Heavy oil field development in Northern Kuwait is currently one of the few thermal "mega-projects" in the world. The development started initially with Cyclic Steam Stimulation (CSS), followed by Steam Flood (SF). These projects need dedicated used water disposal wells. Water disposal wells, initially completed, showed poor injectivity even after CTU acid stimulation with 15% HCl. Based on lab test results and analysis, injectivity was restored with suitable anti-scalant injection and precipitate removal.
Another aspect of these wells was the injection casing shoe-setting depth. A multi-disciplinary team reviewed and established the optimum placement interval for shoe that meets the regulatory and design criteria. The new shoe setting-depth eliminated repeated well interventions during the life of these wells. The learnings were disseminated to various other projects within the company. Quality of source water was also a focus area for the team. Water quality of the source water at various depths were analyzed and tested. Based on the results, optimum well depth and location was ascertained which resulted in improved water quality and quantity.
A novel approach, with key focus on competitive scoping and sustainable development and the combined effort from various stakeholders through an integrated approach have enabled significant savings to reduce the cost of this project. The learnings gathered, and the uniqueness of the project will add significant value to similar projects elsewhere in the world.