Forecasting the Reliability of a Wastewater Disposal System and Predicting Future Corrective Actions using Hydraulic Simulation

Abstract

Abstract Continuous monitoring of wastewater disposal (WWD) systems capacities is necessary given the increase in water production from mature fields. The grave and critical importance of such systems necessitates proactive diagnosing and forecasting of WWD system performances. The precise outcomes of hydraulic simulation have proven reliable in forecasting operational scenarios related to WWD systems. The accurate predictions of hydraulic simulation, coupled with identified time frames and monetary investments, pave the way for accountable and successful managerial decisions. Plant-A injects wastewater into five disposal wells at a given capacity. Historical system performance showed an increase in the pump discharge pressure that has reached near its maximum operating limit. Future production demands entail the need to avail extra injection capacity to this WWD system. A full system analysis of Plant-A disposal network, utilizing hydraulic simulation techniques, was performed to model the current injection performance. The inflow and outflow performance relationships for five disposal wells were generated and calibrated using actual injection data. Network flow analysis was performed to account for both frictional and gravitational pressure losses in pipelines and flow restrictions using sophisticated software. This comprehensive study of the disposal system was aimed at exploring all possible root causes of the discharge pressure increase. In addition, the hydraulic simulator forecasted several feasible and recommended scenarios to eliminate this high discharge pressure. The contemplated scenarios were tapping into a nearby disposal system (either from the pumps suction or through transfer lines to the close by disposal system) and installing horizontal pump systems at the injection wellheads. This paper will present in depth the hydraulic simulation results of the above-mentioned scenarios and highlight their feasibility as viable short-term options. In addition, a detailed account of the associated time periods and respective costs of conceived short-term plans is shown. This high accuracy model improved the decision-making process, and an optimized solution was put into effect based on the simulation results.