Cement Retainers
A cement retainer is a downhole packer-type tool with an integral back-pressure valve that allows cement slurry to be pumped downhole through the tool while preventing cement from flowing back up the tubing after pumping stops. It is the standard tool for squeeze cementing operations — where cement is forced under pressure into perforations, channels, or voids in the casing-formation annulus to restore zonal isolation or repair casing damage.
What a Cement Retainer Does
The cement retainer is set at the required depth — either by wireline or on tubing — above the interval to be squeezed. Cement slurry is pumped down the tubing, through the retainer’s back-pressure valve, and into the perforations or annulus below. When pumping stops, the back-pressure valve closes, trapping the cement under pressure — the squeeze pressure — to force it into the formation.
After the cement sets, the retainer remains in place as a permanent plug. For multiple squeeze treatments at different depths, a new retainer is required for each job — or a retrievable configuration can be used.
Product Range
Wireline Set Cement Retainers
| Model | Feature | Application |
|---|---|---|
| — | — | — |
| MWR | Standard wireline set retainer | General squeeze cementing |
| MWR Semi Composite | Semi-composite construction | Easier milling if removal required |
Accessories: MSS (retainer setting sub), MTC (tubing connector for cement pumping through retainer).
Mechanical Tubing Set Cement Retainers
| Model | Feature | Application |
|---|---|---|
| — | — | — |
| MMR | Mechanical set on tubing | Where wireline is not available |
| MSR | Mechanical set, standard | General squeeze on tubing |
| MSR Drag Block | Drag block anchoring | Positive depth control on tubing |
Key Specifications
| Parameter | Details |
|---|---|
| — | — |
| Setting methods | Wireline (electric line), mechanical tubing set |
| Casing sizes | 4½” – 9⅝” |
| Back-pressure valve | Integral — prevents back-flow after squeeze |
| Milling | Standard carbon steel — millable with tri-cone or PDC bit |
| Standard | API |
Why Source Through Proxima
Proxima stocks MAP Oil Tools cement retainers in standard casing sizes for fast delivery to workover operations across the region. We supply complete squeeze cementing tool packages — retainer, setting tool, and accessories — on request.
Frequently Asked Questions
Q: What is the difference between a cement retainer and a bridge plug for squeeze cementing?
A cement retainer has an integral back-pressure valve that allows cement to be pumped through it and then prevents back-flow. A bridge plug provides a solid barrier but has no flow path — cement must be pumped through the tubing and squeeze tool above the plug. The cement retainer is the purpose-built tool for squeeze cementing operations.
Q: Can the cement retainer be retrieved after the job?
Standard MAP Oil Tools cement retainers are permanent — they remain in the wellbore after the squeeze job and are milled out if the interval needs to be accessed again. Retrievable configurations are available for operations where multiple squeeze attempts may be needed — contact Proxima.
Q: What casing sizes are covered?
MAP Oil Tools cement retainers cover casing from 4½” to 9⅝”. Confirm your casing size and weight when ordering so the correct slip set and element size are supplied.
Q: How is the wireline-set MWR deployed?
The MWR is run on electric line on a standard wireline setting tool to the required depth. The setting tool fires to set the slips and packing element, and is then released and pulled to surface. The retainer is now set and ready for the cement pump-down operation through a tubing string stabbed into the retainer.
