Two-stage Cementer

Two-stage Cementer

Cementing Tools

Stage Cementing Collars / Two Stage Cementing Tools

Product Introduction
Two-stage cementing is the most widely used multiple-stage cementing technique. Although stage cementing was very popular many years ago, new foamed-cement and nonfoamed-ultralightweight-cement technologies have successfully reduced the need for multistage cementing in many operations.


1.Hydraulic stage collar

2.Mechanical stage collar

3.Drilling Free Stage Collar

4.Salvage stage collar

1.Hydraulic stage collar

The HSC-A Hydraulic-Opening stage cementer features inner-closing configuration, opening through pressure difference. The closing plug drivers the closing sleeve to shut the circulation ports.


●Opening pressure can be adjusted and it is not subjective to hole angle or mud properties for operation.

●The pressure-relief design prevents fluid trapping and compression during the opening phase of the tool's operation.

●The I.D.of upper/lower sub is the same as that of casing,but smaller than that of closing sleeve,which can minimize chances of damages to the closing sleeve.

●The inner seats are made of an easily drillable rubber/aluminum material. Both the opening and closing seats lock against rotation for easy drillout.

Technical Data of Hydraulic Stage Collar

Max OD., (mm)170208283381
Drill- out I.D., (mm)122155220315
Overall Length, (mm)1082118212221280
Rated Load,(T)140170210300
Sealing Capacity, (MPa)25252525
Opening Pressure, (MPa)13131314
Closing Pressure, (MPa)5555
Lower Sliding Sleeve I.D.,(mm)85115176203
Upper Sliding Sleeve I.D., (mm)95125197285

2.Mechanical stage collar

Model DYFZ-A mechanical stage tool is a special tool used to complete the cementing operation in two times. Mainly used in the following circumstances.

-Excessive injection of cement at one shot.

-The formation cannot bear the gigantic fluid pressure.

-Packoff special strata.

- Avoid the occurrence of annual air channeling after the cementing job.

-The considerable temperature difference between the upper and lower section makes it rather difficult to adjust the slurry performance.

-Two-stage cementing for deviated and horizontal wells

Technical Data of Mechanical Stage Collar

Opening Pressure(Mpa)7
Closing Pressure(Mpa)5.5
Sealing Capacity(Mpa)≥25
Rated Load(t)180
Connection ThreadAPI 7"
Max. OD. (mm)208
Drill-out ID. (mm)157
Overall Length (mm)990
Length of first-stage plug (mm)320
Length of closing plug (mm)280

3.Drilling Free Stage Collar

The ZTJ-A stage collar is the device for discontinuous cementing operation in two times. It mainly consists of two-stage coupling (built-in hollow plug), first-stage plug, shut-off baffle, free-fall opening plug and closing plug.


● Drilling free stage tool use the standalone action model, that is every action, just is the related part to do, other parts will not be affected, prevent the operation mistake, for example, advance opening and advance closing.

●There have the “two plugs”design for first-stage cementing. That is after first-stage plug downwards to stage tool, and compounded with hollow plug which in the stage tool, use the peculiarity of good isolation impression of hollow plug, solve the question that remain slurry in the inside wall of casing.

●Second-stage cementing use the design of “easy open, easy close, slide smoothly”. Free-fall plug use the heavy design, closing plug use the design of two element composite, it will realize drilling free cementing operation in the real sense.

● All accessories, made from premium quality rubber or aluminum material, have very good anti-rotating mechanism that makes drillout easy.

Technical Data of Drilling Free Stage Collar

Specification(in)51/2 in(Ф139.7mm)
First-stage plug opening pressure,MPa2
Free-fall plug opening pressure,MPa6±1
Closing plug cosing pressure,MPa6±1
Sealing capacity,MPa25
Rated load,ton120
Connection threadAPI 51/2in LTC (BTC)
Max. OD,mmФ174
Drill-out ID,mmФ118
Length of first-stage plug,mm363
Length of free-fall plug,mm240
Length of closing plug,mm295
Length of shut-off baffle, mm320
Overall length,mm1090

4.Salvage stage collar

DLFZ- 7 Stage Collar consists of external casing packer and cementing assembly in one set, complete the stage cementing requirements. After the cementing, the workers must use the dedicated tools to salvage the working core and to realize the hole unblocked.


●The packer use mature casing packer technique, hydraulic pressure rise sealing, constant pressure to shut down.

●The cementing tool use hydraulic pressure to open the circulating hole, to avoid the limitation of the deviation.

●It use inner closing structure, so it can form it-self locking after the closing sleeve closed.

●The working core use salvage mode, so the salvage become easy and don't need to drill, and protect the casing and cementing ring.

● All of the accessories are made of drillable aluminum and rubber and have the non-rotating structure.

●Running the casing strings without grouting, because the tools use auto-fill structure.

●Drii-out free inner core have back-off structure to avoid accident.

Technical Data of Salvage Stage Collar

Packer's opening pressure(Mpa)8 Closing pressure(Mpa)10
Opening pressure(Mpa)15~19 Connection thread7BCSG
Max. O.D(mm)Φ212 Nominal diameter(mm)Φ156
Overall length(mm)6400 Salvage's150
additional weight(KN)

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