Integrated Well Integrity Cement Evaluation Technique for Shallow Gas Flow Cementing in Eagle Ford Field

摘要

Cement job design has historically been a static process largely independent of the other processes in the drilling and completion phases.The success or failure of achieving zonal isolation,which is the main objective of cementing,is usually attributed to the cement placement result without analyzing in details various factors such as drilling parameters,borehole shape,drilling fluid properties,casing designs,formation properties(temperature and pressure profiles),and even cement evaluation methods including post-cement placement activities that could contribute to the end result of achieving zonal isolation objectives for long-term well integrity on an oil and gas well.A unique workflow is developed by incorporating data from different stages of the well construction process(drilling,cementing and cement evaluation)to optimize the cement job design and placement evaluation for critical and challenging wells.By integrating real-time or near real-time data from drilling and cementing phases,the unique workflow rapidly identifies critical information that can prevent poor cement placement,which allows operators to make timely decision to achieve well integrity and safe working environment.An integration of drilling and openhole information,cement slurry design and placement/mud removal result,and cement evaluation log evaluation is required to better understand zonal isolation and well integrity,particularly for wells with shallow hazards.This case study explains an integrated workflow implemented during cement placement design and evaluation on surface casing cementing job after failure of a conventional cement barrier placement in the Eagle Ford field in south Texas.