Method to Operate Water Wells at Optimum Rates Utilizing Orifice Performance Curves

Abstract

Abstract Wells, e.g., water wells (injectors, disposal and supply) operate at designated rates set by reservoir engineers. The objective of producing/injecting these wells at optimum rates is to prolong the well's and reservoir's life. To effectively apply the mentioned objective, each well is assigned a target by the reservoir engineer to either produce or inject. Wells meeting this assigned target are called "compliant" wells while wells that do not meet the set target, whether above or below the target with a specified margin, are classified as "noncompliant" wells. This paper discusses a unique method that will significantly help in maintaining assigned target rates for water wells. The method is applicable to wells that are equipped with intelligent field equipment (DAS—data acquisition system) to monitor the wells in real time. All these wells are equipped with a specific size of orifice plate that maintains a differential pressure (dP), subsequently enabling the flowmeter to read a rate at that point of restriction in the orifice. Each orifice plate, depending on its dimensions, can have its very own orifice performance curve (OPC), which is generated based on multiple parameters. The OPC reflects dP (differential pressure) on its x-axis and flow rate on its y-axis, these curves are beneficial to be used while maintaining the well's target rate. Once a target rate is assigned by the reservoir engineer, a production engineer reviews the OPC and defines the required dP to be communicated for direct field implementation. By this exercise, targeted rates can be obtained without any back and forth communication or field visits for the ultimate goal of achieving compliance in water wells.</jats:p