During my first years in the industry, I quickly realized the importance of proper planning and preparation before of a cementing operation. For such an important, short and intense task, being ready and organized is the most significant element to safeguard people, the well, equipment and the job objectives.
The following steps are some of the pre-job procedures I used to implement before the cement job. They don’t include, however, all the necessary preventive maintenance and required pre-operational testing of equipment.
- At the pre-job meeting, obtain all pertinent job and well information;
- Verify from records that the cementing head, casing swage, quick coupling and casing swivel have been tested. Check that the thread type is compatible with the casing or that a crossover is available; all equipment for the job must have been green tagged;
- Ensure that all other required equipment and tools to be used are in good workable condition;
- Ensure that there are sufficient sample containers;
- Check to see that all materials required for the job are loaded. Verify that the correct chemicals are used to prepare the mix water, this includes proper batch number for each chemical that will be used, as per the laboratory recipe;
- In all cases, for different blends of cement, every blend and bulk tank should be clearly identified;
- Reviews with the CUSTOMER the following job details.
- Independently calculate the required slurry and displacement volumes, using current well data. The two sets of calculations are compared to make sure all volumes are correct.
- Confirm the displacement fluid, e.g., density, drilling mud or water.
- Calculate the total water requirements and make sure is available.
- Review the maximum differential pressure at the end of the job.
- Verify the BHST and BHCT and check them against the cement-system design.
- Check on the prearranged hole conditioning and final mud density and rheology prior to cementing. Recommend additional mud conditioning if necessary and as per the job design.
- Review the number and sequence of wiper plugs.
- Verify the mixing and displacement rates, the pressure to apply when the plug lands (see Casing Pressure Limits) and how many barrels over the calculated displacement volume will be pumped if the top plug fails to bump as expected.
- Ensure that the suction rates required for the job can be achieved for both mud and water.
- Confirm the reciprocation or rotation of the casing and rate.
- Review with the team the contingency plans during the job (e.g., annulus bridges off, pipe reciprocation becomes impossible, pump failure occurs, reduced mix-water supply rate, etc.).
- Review the procedures for pressure testing the cementing and flushing lines.
- Check the mud volume on location. In case the cement job must be aborted during its execution, enough mud should be available at the surface to circulate the cement slurry out of the well;
- Verify all sensors (density, pressure, rates);
- Check pressurised mud balance for correct operation and calibration;
- Just before pre-job mud circulation is completed and check mud properties;
- Load the wiper plugs into the cementing head;
- Conduct pre-job meeting with all involved personnel. This includes the review of the material mixing and pumping sequence, pump rates, slurry densities, contingency plans, safety hazards during the pumping operation and maximum allowable pressure, name a person designated to monitor returns from the annulus, emergency procedures and escape plans;
- Key personnel should have a brief written description of the step-by-step job sequence.
As a professional cementer, you know the importance of this so if you would like to add more checks or just comments, please feel free to write them in the space below
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