R.D. Sehested & L.K. Moran, Dowell Division of Dow Chemical U.S.A.
A liner is probably the most critical string of pipe set in a well. One of the most common problems encountered in liner cementing is the migration of gas in the annulus during the cementing operation. This can lead to a leaky liner top and a subsequent remedial squeeze job. By using proper cementing techniques and materials, including mud removal procedures, gas migration can be minimized and the need to squeeze liner tops can be reduced. Recently, several liners were set in wells in Lea County, New Mexico, in which different drilling conditions and problems were encountered (Table I). This paper presents case histories of these wells and the cementing techniques and systems used to combat these problems.