Finally, the Christmas tree is set, and the equipment and facilities 

 associated with drilling are removed. For marine sites, the procedure is 

 essentially the same except that everything is moved by barge. Sometimes the 

 same vehicles that service an upland site are placed on a barge and moved to 

 the well site to accomplish the task. 



Shutdown of drilling facilities. For the removal of equipment in upland 

 or marsh areas with roads, it is necessary to fill in potholes, shore up weak 

 places, and repair broken boards. The equipment is removed as quickly as 

 possible and taken to the next drilling site. Numerous holes and pits are left 

 behind. The cellar, if present, must be filled. The "mouse hole" and "rat 

 hole," two temporary holes parallel to the wellbore used for temporary storage 

 of drill pipe or casing and the kelly, are filled. 



If steel mud reservoirs have been used, the mud will likely be hauled away 

 to another location. If earthen pits are used, the mud can be hauled away or 

 left at the site. The mud may be allowed to dry and then the levees are bull- 

 dozed over and compacted. Other methods of disposal include burying the fluid 

 in other areas or spreading it over the ground, drying it, and plowing it into 

 the soil. The tailings are usually buried in the shale reserve pit. These 

 types of disposal require that the drilling fluid be clean of oil or toxicants 

 and that the soil characteristics be appropriate to accept the mud. In areas 

 where the pits are lined to keep the mud from seeping or to control toxic 

 materials, it is usually necessary to remove the mud and the pit lining and 

 dispose of them elsewhere. 



Any other temporary pits such as sumps, drains, water reserve, circulating, 

 or spoils pits are skimmed to remove any oil, covered with earth, and compacted. 

 On upland sites, all that remains at this stage is the Christmas tree, pad, and 

 newly covered pit area. On marsh sites, the Christmas tree, board mat, and 

 levees remain. Depending on future plans, the mat may stay or be removed. The 

 levees are generally left, though land owners may require that smaller levees 

 be built around the wellhead for production equipment and that larger levees be 

 breached. 



For unsuccessful wells, there is often a state requirement for the final 

 condition of the hole. It must contain mud and a long concrete plug near the 

 upper end. Casing must be cut several feet below ground surface (below plow 

 depth). In abandoned upland sites, the pad usually remains. In marsh sites 

 with board mats, the boards are often removed completely. The land owner may 

 require levee breaching as well. Roads and levees (on which board runs are 

 laid) are usually not removed. If further oil and gas activity is expected, 

 the boards on the levee may be covered with a layer of shell or crushed rock. 

 However, if the location is to be abandoned completely, the board run is removed 

 for use at another site. Board runs laid directly on marsh soil are nearly 

 always removed, whether the well is a producer or not. 



100 



