The limits of directional drilling continue to be pushed back as horizontal or near horizontal reservoir sections are being drilled, cased, cemented and completed to tap reserves at extreme distances. Continuous development of new technology and adopting a technical-limit approach to performance delivery are key elements for the success and further development of extended-reach drilling projects.
For this study a two-phase well control simulator was used to evaluate different kick scenarios that are likely to occur in extended-reach wells. An extensive simulation study covering a vide range of variables has been performed. Based on this investigation together with a literature review, well-control procedures have been developed for extended-reach wells.
The most important procedures are as follows:
- Perform a “hard” shut-in when a kick is detected and confirmed.
- Record the pressures and pit gain, and start to circulate immediately using the Driller’s Method.
- Start circulating with a high kill rate to remove the gas from the horizontal section.
- Slow down the kill circulation rate to ½ to 1/3 of normal drilling rate when the choke pressure starts to increase rapidly.
The simulator has been used to validate the procedures.