Successful Logging Operations Through Y-Tool; Challenges and Lessons Learned on Restricted Completions

Al Zahrani, Ahmed R. (Saudi Aramco) | Kalu-Ulu, Torty C. (Saudi Aramco) | Al Nasser, Ahmed N. (Saudi Aramco) | Al Yami, Salem F. (Schlumberger)



Artificial lift utilizing Electrical Submersible Pump (ESP) supporting operations have evolved from pump installations with no access to the completion zone to the point where rigless logging intervention operations can access the lower wellbore using either coiled tubing or wireline. Access to the completion zone has been accomplished through the installation of Y-Tool and a by-pass leg in conjunction with the ESP.

The major challenge is to have the Coil Tubing (CT) plug seal assembly located on the coil otherwise a damage to the seal assembly is expected and consequently a fluid circulation might take place. CT conveyed production logging requires a CT plug to prevent production circulation across by-pass section while operating the ESP. The circulation is prevented by the seal assembly which exists in the CT plug and located on the coil tube. The Bottom Hole Assembly (BHA) consist of CT plug which included connector, sleeve and bottom crossover, all covered by the CT plug external body which has the seal assembly in addition to the Production Logging Tool (PLT). Changes in tools design and profiles allowed for a successful logging intervention into these Y-tool equipped wells while gathering required well logging data.

The paper presents technical and logistic challenges during rig-less logging operations on wells with a Y-tool and a by-pass leg with complicated downhole configuration including small restriction and dual pump layouts. Examples of both impaired and successful operations will be reviewed with challenges and lessons learned, including the changes made to allow the tools for logging activities. This paper will provide a path forward to well access and surveillance while ensuring adequate isolation during logging operation.


The reliance on Electrical Submersible Pumps (ESPs) in oil fields operations is increasing and will continue to grow in the coming years due to the eminent decline of reservoir pressure and early water breakthrough associated with high production demand overtime. More ESPs will be required to sustain production for a period of time. In addition, more wells’ data acquisition and interventions will be frequently required to monitor wells integrity and performance. Therefore, an ESP system with Y-tool bypass section is utilized to enable data gathering and access to the wellbore below the ESP assembly using coil tubing (CT) or wireline (WL) deployed interventions. Production logging operations are required to monitor well performance, water production intervals, and other well parameters via the Y-Tool-ESP completion.