Are there any well designs that can mitigate well structure damage caused by subsidence?
A4. One successful design to mitigate structural damage to the well incorporates the use of a of a specially constructed compression section installed in the upper blank cased section of the well. The compression section consists of three sections of blank casing with the center section being 2″ larger in diameter. With special couplings holding the sections together, the two end sections can slide within the center section. The entire compression section is approximately 18-feet long and can be made in any diameter up to 24 inches. The unit is typically placed at the depth where subsidence is likely to occur. Under for these conditions, compression sections have adjusted to the additional collapse and tensile pressures exerted by the subsiding geologic units surrounding the well. Specific information regarding the construction and application of the compression section can be obtained by contacting the Roscoe Moss Company ‘s Los Angeles office.
