An integrated digital automation system has been used successfully to efficiently optimize tubing flow control and plunger lift installations in North San Juan basin. This paper presents description, application, and significant results achieved by using an intelligent closed looped digital integrated automation system. Results included increased gas production, equipment reliability, also, efficient and inexpensive deliquification method through almost exclusively remote-controlled operations.
The smart digitally enhanced system consists of two parts; the Remote Terminal Unit (RTU) and the SCADA-host. The common RTU application is deployed across all well sites and utilizes a common application load. Where and when needed, new feature selections have been added however complete backwards compatibility has been maintained. This is made possible mainly by abstracted I/O and a modular programming technique. The SCADA-host which is also a common unifying system provides interface to all wells for surveillance, monitoring and control capability. The system displays the current system layout graphically. Historical trends are also easily retrievable.
Gas production increment of over 4MMcfd has been achieved and sustained in less than 40 plunger lift installations mainly due to availability of high quality digital automatic control system coupled with effective utilization of plunger lift data. By itself, the system adjusts plunger arrival time, after flow and shut-in time based on pre-set operating range to maximize gas production. Thirty tubing flow control installations have resulted in an average gas production uplift of 130Mcfd per well. In tubing flow control application, the casing valve is automatically controlled based on well conditions. This allows a well to flow gas through tubing above critical gas rate while releasing friction and backpressure on the formation by producing additional gas through the tubing-casing annulus. It is a simple process that includes a combination of surface equipment and control logic that could not perform faultlessly without intelligent automation system.
This is a significant departure from the traditional means of operating gas wells where highly expensive full rig intervention is required to continuously optimize tubing size and artificial lift installation. As expected, improved business performance has been achieved through an intelligent integrated digital automation system.