Using Autonomous Control to Maintain Gas Lift Well Flowing Bottomhole Pressure
Authors
Zhuo Gao
Publisher
SPE - Society of Petroleum Engineers
Publication Date
October 31, 2022
Source
ADIPEC, Abu Dhabi, UAE, October 2022.
Paper ID
SPE-211050-MS
Abstract
Optimizing a gas lift well can be challenging as it needs to optimize a complex interdependent system, where gas is compressed and injected to the bottom of the well to lift oil/water/gas to the surface. This system contains numerous facilities and equipment, from the compressor, injection valves, downhole gas-lift mandrel, valves, wellhead, and surface separator to the sales lines. Flowing bottomhole pressure plays a critical role in the system. In many cases, stabilizing the flowing bottomhole pressure within a desired range can be considered optimization of the system.
An edge internet of things (IoT) platform provides customized autonomous control logic to accommodate the customer's optimization challenge at the well level. Weatherford deployed the customized autonomous control logic to optimize the gas injection rate based on liquid production, well stability and to adjust an automated wellhead choke to maintain the flowing bottomhole pressure within the desired range.
The field results show that the methodology deployed has been able to maintain the flowing bottomhole pressure, optimize the gas injection rate, minimize the buy-back gas, and reduce the manual intervention, which, in return, largely reduced the optimization workflow's OPEX and boosted the production. In the eight-week trial, the flowing bottomhole pressure has been maintained within the target range 99.9% of the time, production was enhanced because of the optimized operating condition, and reduced the buy-back gas cost by 28%. A significant improvement in personnel efficiency was achieved by saving 8 trips/well which also reduced OPEX over the entire pilot.
The next-generation automation device incorporates the industry 4.0 technology to deliver customized autonomous control logic that leverages high-frequency, real-time data and well analysis to improve the optimization granularity. It maximizes the values that are delivered to the customer at the well site.