Suggested placement of ROTCO’s solid slip-on centralizers with the ROTCO centralized up-jet float shoe and ROTCO centralized float collar (optional):
  1. ROTCO centralized float collar or slip a solid slip-on centralizer on the 1st joint before putting on the float shoe. Slip the centralizer up near the top of the 1st joint.
  2. On 2nd joint slip a sold centralizer near the upper end of the joint.
  3. On 3rd joint slip a solid centralizer near the upper end of the joint. Keep casing shoe up off bottom enough distance to allow for casing elongation (5-10ft. minimum, depending on depth). ROTCO Centralized Up-Jet Float Shoe

   
  Placement of the ROTCO Intercasing Centralizer on Integral Flush Casing For close tolerance wellbore/casing annulus productive zones:
  1. For long productive zones, screw into casing string 1 inline centralizer per joint, 1 joint apart throughout the productive zone.
  2. For short productive zones (less than 40 feet) use a casing pup joint with an inline centralizer on each end of the pup joint.
  3. For drilling liners, use ROTCO centralized Up-jet Float Shoe and centralized Float Collar, 2 Intercasing Centralizers above the Float Collar and 2 in lower liner overlap.
  4. For liner overlaps, place 1 Intercasing Centralizer near the bottom of the overlap and 1 near the liner hanger.

Note: Pipe reciprocation or rotation with any fixed centralizer will deteriorate standoff because of the wear of the centralizer and/or formation.

  
  Conductor Casing



Objective: To achieve good cemented shoe joints and good upper cement coverage for load support. Approved centralizers for sub-sea wellhead wells.



Solid Centralizer Placement (1 per joint):
  1. Place 1 solid slip-on centralizer 5-10 ft. from float shoe.
  2. Place 1 solid slip-on centralizer in middle of 2nd joint from float shoe.
  3. Place 1 solid slip-on centralizer in drive pipe overlap for wellhead alignment and load distribution, and later for improved cutting on abandonment.
  4. ROTCO Centralized Up-Jet Float Shoe to assure good cement coverage around the shoe joint.
  
  Surface Casing



Objective: To achieve good cemented shoe joints and shoe tests. To get isolated zones of good cement. Sub-sea wellhead approval.



Solid Centralizer Placement:
  1. Place 1 solid slip-on centralizer 20ft. from ROTCO ‘s Centralized Up-Jet Float Shoe.
  2. Place 2 solid slip-on centralizers per joint separated by a stop ring in the middle of the joint on each of the next 2 or 3 joints from the shoe.
  3. Place 1 solid slip-on centralizer above and below a cement stage collar
  4. Place 1 solid slip-on centralizer in conductor casing overlap for wellhead alignment, good top out cement job for load distribution and better cutting on abandonment.
  5. Place 1 solid slip-on centralizer per joint from surface fresh water zone to regulated depth for saltwater isolation.
  6. ROTCO Centralized Up-Jet Float Shoe to assure good cement coverage around the shoe joint.
  
  Protection Casing (intermediate)



Objective: To achieve good cemented around the shoe joints. To achieve isolated zones of good cement. Solid Centralizer Placement
  1. Place 1 solid slip-on centralizer 20ft. from ROTCO ’ s Centralized Up-Jet Float Shoe.
  2. Place 2 solid slip-on centralizers per joint separated by a stop ring for 3 to 4 joints above the float co. llar
  3. Place 2 solid slip-on centralizers in the surface casing overlap (near bottom and 1 near casing hanger).
  4. for production intervals see Production Casing.
  
  Production Casing



Objective: The objective is to achieve casing standoff throughout the productive intervals. Stand-Off will allow complete mud removal and complete cement coverage. Solid casing centralizers can be perforated through with no deformation or degradation of shot.



Solid Centralizer Placement
  1. Place 1 solid centralizer on shoe joint above ROTCO Centralized Up-Jet Float Shoe.
  2. Place 2 solid slip-on centralizer per joint throughout all productive intervals. If casing is to be rotated and/or reciprocated, do not run with set screws. The solid centralizers will then serve as a centralizer bearing while the casing is being worked. The solid centralizer normally will remain stationary while the casing is worked within.
  
  Drilling Liner



Objective: To achieve good cement coverage around the casing shoe joints and liner overlap.



INTERCASING CENTRALIZERS FOR CLOSE TOLERANCE WELLBORES
  1. Run a ROTCO Centralized Up-Jet Float Shoe.
  2. Run a ROTCO Centralized Float Collar.
  3. Screw 2 intercasing centralizers on the next 2 joints above float collar.
  4. Screw 2 intercasing centralizers into the liner for casing liner Stand-Off in the bottom 80ft. of the liner overlap.

SLIP-ON

  1. Run a ROTCO Centralized Up-Jet Float Shoe.
  2. Run a ROTCO Centralized Float Collar.
  3. Run 2 per joint solid slip-on centralizers on next 2 joints above float collar.
  4. Run 2 per joint solid slip-on centralizers on 2 joints of liner in lower liner overlap.
  
  Production Liner



Objective: To achieve casing stand-off through the productive intervals and liner overlap for complete cement coverage.
  1. Place 1 or 2 solid centralizer per joint through the productive interval. Short productive intervals may require casing pup joints for additional installation of the intercasing centralizers through the productive interval.
  2. Place 2 solid centralizers in the bottom 80ft. of liner overlap.
  3. Run a ROTCO Centralized Up-Jet Float Shoe
  

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