W.G. Storbeck, Storbeck Consulting, K.C. Hampshire, Mobil E&P US
Multilateral horizontal wells have been used as an approach to further improve production and injection volumes. As a result, very often the steep hyperbolic decline seen in a single lateral well is reduced. The first approach used was with a milled casing section in which several laterals are drilled off a cement plug. Subsequent laterals are then sidetracked off the main laterals drilled. These laterals are 4 314 inch openhole with no liners. Reentering these laterals is costly when doing initial stimulation work for completion. Considering the future need to clean out fill or other precipitants with a bit and also to restimulate, a lower risk well design was desirable. With the help of Weatherford Enterra, a system designed using a permanent packer and retrievable whipstocks was used to address the problems and costs of finding multiple laterals. The system has considerably reduced the amount of time it takes to locate each lateral and greatly improved the likelihood of doing so at a later date.