Key factors in framing a produced water management (PWM) strategy include a company's internal and external environments, technology and business drivers. Emerging trends for establishing an environment-friendly PWM position can comprise these declared policies:
Move toward Zero Emission
No Discharge to surface or seas
Incremental and progressive separation Pro-activity to influence partners, regulators and environmental laws
This paper covers the technical approaches for addressing production, separation, and disposal/injection segments of water injection and reservoir waterflooding and the basis for selecting strategy components and PWM actions. Best practices result from both comprehensive assessments of current PWM tools and insights from a decade-long, joint industry project (JIP) on produced water re-injection (PWRI).
PWRI for waterflooding or disposal is an important strategy for deriving value from waste, while preserving environmental integrity during E&P operations. Advances in best practices and lessons learned for injector design, operation, monitoring, assessment, and intervention provide the basis for cost minimizations and green operations. Facility and subsurface engineering are linked through PW quality targets, pumping needs, injector completions, and facility constraints. Field cases and data mining results1 show the variation in injector responses and underline the basis for performance. Field evidence indicates that injectivities suffer in matrix injection schemes despite the injection of clean water. Alternatively, injectivity maintenance using untreated produced water is feasible.
The majority of injectors fracture during injection, thereby impacting facilities SOR, injector completion, sweep and vertical conformance. This paper assesses fracture propagation during seawater and produced water injection and its impact on injector performance. Models depicting formation and fracturing plugging, vertical water partitioning and well testing are discussed. Best practices are highlighted and the impact on injection strategy outlined. Several field cases, water injection design and analysis tools for quantifying the impact on flood and well performance are presented.