Abstract
An important aspect of horizontal hole completions is selection of downhole tools for placement and control of stimulation fluids. Physical parameters imposed by the curved and horizontal sections of a wellbore can severely limit the number of tools, and indeed, the number of tool systems that will provide effective reservoir stimulation. The selection of an appropriate total stimulation program is optimized when the downhole tool string options are considered in the planning stages, before the well is drilled. Completion style and tools to be utilized have direct bearing on the drilling operation.
Some conventional tool assemblies that operated successfully in vertical hole are readily applicable to stimulation treatment operations in horizontal wellbores. Consideration of modifications of existing tools, tool limitations, new tool applications, and particular attention to details of operating procedure in early stages of the well can maximise the total Stimulation program.
In this paper, case histories of tool systems developed for different interval treatment techniques and successfully used in horizontal hole stimulation are presented. Straddle packer systems, permanent packers for zone isolation, and selective injection packer systems are among the examples. Factors in selecting an appropriate stimulation tool system for horizontal completions are discussed. New tool systems under consideration and/or development are presented.
