Some surface owners may require that covered, filled, or leveed areas be 

 seeded and fertilized. In the majority of cases, however, these areas are 

 revegetated by natural spread of vegetation. 



To remove the equipment from marine sites, the canal must be checked to be 

 certain it has not shoaled. If shoaling has occurred, a bucket dredge is used 

 for maintenance. The ballast is pumped out of the drill barge; the drill barge 

 and all the supply barges are moved to the next location. If the well was 

 successful, production equipment and flowlines will be placed. It is common 

 for a pile driver to enter and drive piles around the wellhead. A structure 

 will be built around the Christmas tree for protection from collision and for 

 access to valves and pipes. 



For unsuccessful wells, the wellbore is filled with mud, and a long concrete 

 plug is placed near the surface. Often, the surface casing will be cut more 

 than 3 m (10 ft) below the sediment-water interface. Any pilings around a 

 keyway are removed so there are no obstructions in the slip. If the slip and 

 canal will not be used further, the channel may be plugged or have a wier 

 placed in it. The construction of a plug in an exploration canal is rare since 

 the canals are often part of a maze of canals and are eventually used for 

 access to other sites. Construction details of canal plugs will be covered in 

 the section dealing with pipelines in marshes. 



Placement and Operation 

 of Production Facilities 



Production is divided into two phases: (1) the construction and placement 

 of production facilities and (2) the operation of those facilities. The former 

 phase consists of placing flowlines, treating and storage equipment, and brine- 

 disposal equipment. The latter phase consists of the start-up of production, 

 continuous operations procedures, and shutdown of operation. 



Flowlines - upland and diked marsh. In upland and diked marsh areas, 

 where there is the possibility of vehicle travel, flowlines are buried below 

 the land surface (below plow depth). A route will be planned, and a survey 

 party will enter the area to stake the route. There may be some vegetation 

 removal at this time. Once staked, equipment is brought into the area, and 

 enough vegetation is cleared to facilitate burying the flowline. A ditcher or 

 a plow may be used to dig a trench for the flowline in firm soils. In very wet 

 soils, the flowline may be placed on the levee to the wellsite location or on 

 the marsh surface paralleling the road that leads to the wellhead. The pipe 

 sections are coupled with tubing joints, and buried pipe may be coated to 

 control corrosfon. After placement of the pipe, the ditch is filled or a 

 tractor is run over the plow hole. The flowline is pressure-tested, usually 

 with a fluid at a higher pressure than expected for operation. If the pressure 

 holds for a specified period, the line is ready for use. The flowlines reach 

 all the way from the wellhead to the production facilities, usually no more 

 than a few miles. 



101 



