Shutdown. Shutdown of drilling operations occurs when the drill rig is 

 moved away. All equipment except Christmas trees and production devices are 

 loaded onto trucks or barges for transport. The removal or leveling of roads, 

 levees, or excavations usually depends upon the requirements of the surface 

 owner. Roads and levees are generally left intact if there are other locations 

 to be drilled or if there is significant production. Reserve pits and mud pits 

 are nearly always filled and leveled. 



Shutdown at the wellhead may take several forms. If a producing well has 

 been drilled, a protective cage may be placed around the wellhead and production 

 equipment installed nearby. If the well is only a marginal producer, it may be 

 capped to await either further treatment or change in the petroleum price so 

 that it becomes profitable to produce from that well. If a "dry hole" has been 

 drilled, it is capped below the ground surface, and all equipment is removed. 

 If a well that has been a producer ceases to produce profitably, it may be 

 capped for "workover" at a later date. If the producing company believes that 

 the oil-bearing formation has been depleted to such an extent that further 

 production is not economically feasible, the well may be capped like a dry 

 hole. 



When formerly productive wells are abandoned, roads and levees are gener- 

 ally left intact. On occasion, breaches are made in dikes and levees, particu- 

 larly in marsh areas. However, since repair can be a significant expense to a 

 production company, it is usually done only at the request or requirement of 

 the surface owner. 



When production in an entire field is no longer feasible the surface 

 flowlines and production equipment are removed. Unless the equipment is in 

 very good condition, it is often sold on site for scrap since it is expensive 

 to transport and recondition. After the field has been abandoned, the main 

 remnants are roads, canals, levees, pipes in the ground, and concrete founda- 

 tions. 



DETAILED ACCOUNT OF TYPICAL 

 OFF-REFUGE OIL AND GAS ACTIVITIES 



The following is a detailed account of typical oil and gas industry methods 

 and techniques. There are specific differences in methods and techniques 

 required by refuge management. Except for these differences, oil and gas 

 activities are carried out in the same manner on and off refuge lands. 



Appendix A contains an outline of the activity steps described in this 

 section. Specific estimates of activity duration and areal extent are also 

 found in this appendix. 



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