In PDO, ESP wells are attended at site mainly during commissioning activities, during wells trips, or during routine physical well performance check. These activities, which are action by ESP vendor (mainly Commission Engineer) accompanied by a Company Site Representative (CSR) and sometimes with Field Programmer, can arise with noticeable challenges, in particular the troubleshooting ones, which require over the edge techniques solutions.
It has always been the focus of the Company to revive those tripped wells back to production at fast track to minimize oil deferment and avoiding a major well intervention. In addition, the routine physical performance checks are encouraged to identify optimization opportunities.
All the wells, which are tripped, are put on oil deferment in the company Production system, to initiate troubleshooting activities. In these wells, the common routine troubleshooting activities were attempted with no success. Upon thorough diagnosis using real time data, understanding of the well condition, fluid characteristics, the nature of trips and the trip values, the wells were re-visited, and the procedures were reviewed & altered to match the overall well condition and settings.
The same methodology was adopted to identify the wells for optimization by combining the knowledge of the subsurface measured real time trends with the surface parameters & capacity while trending with the nearby wells at same type reservoirs resulted in identifying the optimization opportunities.
This modified approach on ESP troubleshooting activities to bring tripped ESP wells back to production, which has caused oil deferment has currently saved few work-over operations, thereby saving well intervention cost and has minimized deferment to almost zero m3/d. In addition, these improved troubleshooting activities have resulted in establishing fit for purpose procedure recommendations that enabled to work with challenging troubleshooting activities. Moreover, the identified optimization opportunities have increased the production rate to two folds in some ESP wells.
The main activities performed inthe well site to revive these tripped wells, which were already pronounced failed were:
Modified back flush procedures: pumping the fluid through annulus while ESP is running. This was carefully done while checking the surface load on the controller.
Altered / by pass the trip settings till the production is stabilized
For optimization opportunities, the frequencies / chokes were increased & reduced until well stabilized.
This approach has led to improvement initiatives across PDO, namely:
Establish a standard practice of troubleshooting tripped wells in PDO instead of current practice embedded with real time automated well models in Well Management System.
Revise alarms & trip setting to match the individual well characteristics, subsurface & surface, instead of current practice of "one standard" for all ESP wells, which create false alarms / trips.