A non-rig Coiled Tubing Unit (CTU) cement squeeze technique has been developed and proven in the Prudhoe Bay field. This new technique does not require that the well be killed. The channel and perforations remain clean and unobstructed allowing easy placement of cement. This process utilizes in-situ contamination of cement left in the well bore after the squeeze. The contaminated cement is then circulated or reversed out of the wellbore after the squeezed cement has set, eliminating the need for drilling. The technique has been used to shut off channels in the primary cement to both the aquifer and the gas cap, to squeeze off unwanted production perforations, and to alter injection profiles. Workover costs for these types of jobs have been reduced an average of 85% by utilizing the CTU technique. Scale modeling, fullscale testing, and field operating experience were drawn upon in developing this technique.

Keywords:
drilling fluids and materials, coiled tubing, perforation, contaminant, wellbore, drilling fluid selection and formulation, drilling fluid property, bopd, fluid loss, upstream oil & gas
Subjects:
Drilling Operations, Drilling Fluids and Materials, Casing and Cementing, Well & Reservoir Surveillance and Monitoring, Improved and Enhanced Recovery, Formation Evaluation & Management, Drilling fluid selection and formulation (chemistry, properties), Perforating, Completion Installation and Operations, Well Intervention
Copyright 1986, Society of Petroleum Engineers
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