Good cement behind casing for hydraulic isolation is one of the critical aspects of well completion and hence productivity (Conoco Phillips, 2013). Currently, the conventional approach for cement design is primarily controlled by drilling-and-completion and evaluation (wireline and data) services, where different disciplines work independently and generally tend to overlook some critical design parameters such as gas influx, caliper size, leak off test parameters etc., which results in poor cement placement. This affects the safety of the well and could be a costly disaster (National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, 2011).
A unique workflow - Invizion, has been developed to incorporate data from different stages of the well development (drilling, cementing, and evaluation) and it has excellent potential to improve cement design for both ongoing drilling projects and future wells. This allows real-time cross-segment computation and enhanced interpretation view, which, in turn, helps improve the overall understanding of the cement job design. Thus, Invizion has excellent potential to improve cement design for both ongoing drilling projects as well as future wells.
Invizion workflow was deployed and used in drilling and cementing of a well in the Eagle Ford formation in Texas. With the new workflow introduced, the well was drilled and completed without any well-integrity incidents as compared to a previous offset well in the same area which was affected due to gas influx. Tail and lead cement were determined successfully with wireline logs which also confirmed modelling results through the Invizion workflow. Integrating offset wells data helped in better understanding on the potential cross flow area which affects cement placement. Key recommendations were also provided for improving cement jobs for future drilling program. The workflow also helped established better communication and knowledge sharing between cement evaluation experts and drilling and completions groups.
The Invizion workflow rapidly identifies critical information that can prevent poor cement placement by integrating real-time data from formation evaluation with drilling and cementing. This allows operators to make timely corrections that can maintain well integrity, assure well-site safety, and potentially avert costly disasters.