Timothy R. McNealy and Dr. Stuart Scott - Bob L. Herd Department of Petroleum Engineering, Texas Tech University
In this paper, improvements to the Artificial Lift Map (ALM)[ref] have been made. The ALM is a tool, a 2D chart, of the Gas Liquid Ratio (GLR) versus Liquid Flow Rate (QL) for a single or multiple Wells. This tool can be used to improve Artificial Lift (AL) selection, field planning and overall operational efficiency. Within the chart are regions defining the operation envelopes for the various AL types. Each of the operational envelopes is separated by guardrails, boundaries, defining the limits for each of the AL systems. These guardrails were originally based on industry rules-of-thumb and now they have now been validated via case studies and published research. In addition to AL selection, the ALM can also be used as a surveillance tool for Wells. The actual production/test data is overlaid on the ALM to illustrate which AL system is currently being used and what AL options are available. The ALM can also be used to show an AL’s operational status. Performance indicators can be displayed for each Well, such as gas injection rates, pump uptime, number of failed plunger trips, etc. Type curves can be used to forecast a Well’s production by plotting the trajectory over time to advise in various AL selection throughout a Well’s life cycle. Correct AL selection for each phase of production is critical to optimizing the economics of a Well or an entire asset. Timing is important when transitioning between AL types to avoid any lost revenue, as the optimization of an AL is also time dependent. Papers have been written on Electrical Submersible Pump (ESP) verses Gas Lift (GL) and depending on the reservoir, hydrocarbon properties and facilities available/planned, shouldn’t it be seen as an ESP to GL transition, the ALM is designed to help answer some of these questions. Furthermore, reactive transitioning between AL types (ESP failure) instead of proactive transitioning (installing a GL and facilities) can increase the operational cost. Additionally, operating an AL system at a low efficiency also increases operational cost. Cases are presented for various AL types, transitioning and production forecasting. Optimally timed transitioning between some systems has shown an upwards of 50% reduction in power usage.