Process Automation for Integrated Gas Lift Surveillance and Optimization at Large Scale

Abstract

The super-giant field under study is one of largest oil producers in Middle East and been producing for more than 50 years from a multilayered carbonate reservoir. Long-term sustainability of production of the field is a key mission for the field operator and national oil company, considering both productivity and recovery of the field. Gas lift has been considered as an effective and economically feasible method to increase production of the wells and as a solution to revive the closed wells and to maintain the production of flowing wells. Prior to full field implementation, a gas lift pilot has been initiated in the field. The objective of the pilot is to collect further essential information and evaluate the challenges prior to the full field implementation. At the well scale, managing the well lift rate allocation, monitoring the performance of gas lift valves and running diagnostics, and optimizing the production rate are the main challenges for the gas lift pilot. At the full field network level, the backpressures of the lifted wells are affecting the production of the other wells producing naturally. A commercial three-phase flow simulator was used to build the well models as well as the pilot network, with certain boundary conditions to develop a scalable solution to enable the operations and headquarters teams to provide a timely solution to the mentioned challenges. To integrate all inputs from various disciplines, the information from the monitoring activities and from reservoir saturation and production logging tools in addition to well test data and gas lift surveys was used to develop the solution. The gas lift management solution was evaluated in the pilot area to diagnose the gas lift valves, validate well tests, optimize gas lift allocation, enhance well production, and perform field-wide production optimization The solution also reveals gas lift candidate wells with the potential to increase the production and directs redistribution of the lift gas in the pilot area to minimize gas utilization. Additionally, to introduce scalable solution which can be utilized at very large wells count, automation of the workflow process has been considered to provide efficiency for engineers which will get advise from the solution.