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 936.521.2200

 NOV CTES
 9870 Pozos Lane
 Conroe, TX 77303
 936.521.2200
 936.521.2275
 

 NOV CTES - UK
 1 Claremont Street
 Aberdeen, AB10 6QP
 44 (0) 1224 588788

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 4910 80 Ave SE
 Calgary AB T2C 2X3
 403.203.1581

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 Al Ghaf 4a
 appt 109
 Dubai U.A.E.
 971 50 275 4530

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CEMENT PULSATION - IMPROVE ZONAL ISOLATION WITH SURFACE PRESSURE PULSES

Cement pulsation is the application of low-intensity pressure pulses to the annulus after a primary cement job to break the gel strength development in the cement slurry. Gel strength of the cement causes a lowering of the hydrostatic pressure transmitted through the annulus. By breaking the gel strength, the hydrostatic pressure on the formation is maintained until the cement has built sufficient strength to prevent the influx of reservoir fluids through the cement matrix.

Benefits

  • Eliminate remedial squeeze jobs
  • Prevent annular casing pressure
  • Provides real-time indication of the cement curing process
  • Improved cement logs
  • No adverse affects on the cement properties
  • Simple, cost effective solution to control fluid migration

Field Operation

The patented cement pulsation process starts immediately after cement pumping stops and the annular BOP is closed. Low pressure
pulses, typically in the range of 80 to 200 psi, are applied to the casing annulus at a time interval of 30 to 60 seconds.  Pulsing continues until the compressible volume levels-off or the laboratory thickening time indicates the cement has reached 70 Bc, usually in 4 to 6 hours
.

 

 

Cement Pulsation Schematic

Cement Pulsation Equipment Schematic

Equipment Specifications

  • 9'Lx6'Wx8'H
  • Weight: 5,300 lbs
  • Process Control
  • 2 Tank (ASME)
    • 200 gallon
    • 200 psi working pressure
  • Sensors
    • water level
    • annulus pressure
    • air tanks pressure
    • discharge flow

Hydrostatic Pressure Decrease During the Cement Setting Process

Hydrostatic Pressure Decrease
During the Cement Setting Process

 

Download a brochure (pdf)

Cement Pulsation Articles & Papers

SPE 94230: "Preventing Annular Flow After Cementing, One Pulse at a Time: Offshore Gulf of Mexico Cement Pulsation Field Results"
SPE 77754: "Transient Pressure Uploading - A Model of Hydrostatic Pressure Loss in Wells after Cement Placement"

SPE/IADC 37619: " Reciprocating Cement Slurries After Placement by Applying Pressure Pulses in the Annulus"
SPE 77752: " Cement Pulsation Treatment in Wells"
SPE 71387: "Well Cementing Diagnosis From Top Cement Pulsation Record"
SPE 75699: "Field Study on the Use of Cement Pulsation to Control Gas Migration"
GasTIPS Article: "Preventing Annular Flow After Cementing in the Shallow Gulf of Mexico"

World Oil Article Summary: "Confirming Surface Pulses Reach Total Depth and Can Improve Gas Well Cementing"

Hydrostatic Pressure Loss/Annular Flow After Cementing Articles & Papers

JPT Article, 1983: "Field Measurements of Annular Pressure and Temperature During Primary Cementing"
JPT Article, 1972: "A Study of Completion Practices to Minimize Gas Communications"
ETCE 17133: "Experimental Assessment of Methods to Maintain Bottomhole Pressure after Cement Placement"
SPE 5701: "An Investigation of Annular Gas Flow Following Cementing Operations"

SPE 4783: "The Inability of Unset Cement to Control Formation Pressure"
SPE 5517: "Gas Leakage in Primary Cementing: A Field Study and Laboratory Investigation"
SPE 5898: "Filtrate Control: A Key in Successful Cementing Practices"
SPE 8257: "Study of Factors Causing Annular Gas Flow Following Primary Cementing"
SPE 9285: "Transition Time of Cement Slurries between the Fluid and Set State"
SPE 11982: "Critical Design Parameters to Prevent Gas Invasion During Cementing Operations"
SPE 14199: "Primary Cementing Improvement by Casing Vibration During Cement Curing Time"
SPE 90829: "Transition Time of Cement Slurries, Definitions and Misconceptions, Related to Annular Fluid Migration"

Case Histories

Offshore GoM - Preventing Annular Flow/Pressure After Cementing

Milestones

Commerical Cement Pulsation Service Passes Two Major Milestones

For additional information or quotation contact Ed Smalley at (936) 521-2222.



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