This document describes typical minimum cementing standards and practices that enable the planning, successful execution and evaluation of cementing operations.
1. The Well Programme shall incorporate a cementing programme, which shall include as a minimum:
a. Planned tops of cement and justification.
b. Cement slurry and spacer design and recipes.
c. Theoretical thickening time that will be compared to the final laboratory test done with rig samples.
d. Displacement rates and expected pressures.
e. Estimated ECD during pumping operations versus Formation Fracture gradient.
f. Excess volume recommendations and justifications.
g. Pressure rating of the cementing equipment like cementing head, cementing plugs, landing or float collar and associated float/check valves.
h. Plug bump and primary pressures test.
i. Contingency action in case of losses during the displacement.
j. Contingency action if the float equipment fails to close.
k. Any requirement for cement evaluation.
2. Sufficient cement and additives shall be held at the rig-site to set two 100m cement plugs in the current hole size when hole size is less than 20 inches.
3. Change of the cementing programme must be approved in writing by the Drilling Superintendant before the start of cementing operations.
4. All safety related properties of cementing additives and necessary handling procedures shall be known and Material Safety Data Sheets (MSDS) must be available at the rig-site.
5. The well-bore shall be adequately conditioned prior to cementing operations to remove gas and cuttings and to ensure an optimum rheology.
6. Prior to cementing, all cement lines and all connections that will be used for the cementing operation shall be pressure tested. The pressure test shall be 1000 psi above the maximum expected pump pressure.
7. The Drilling Supervisor shall prepare a cementing report where all the different aspects of the operation will be detailed from the pressure test of the cementing lines to the bleed off of the pressure after the plug has bumped, all the volumes pumped and recovered, etc. This report will be attached to the associated casing tally
8. A sample of cement shall be taken each time bulk cement is arriving onshore at the well location.
9. The Drilling Supervisor shall ensure that the cement delivered correspond to the cement that was ordered.
10. The bulk cement silos shall have:
a. An air drier in good condition to ensure that only dry air is used in the silo pressurised system.
b. Separate loading and discharge lines for cement and mud products.
c. Silos and surge tanks must be fitted with accurate weight indicators – The weight indicator must be certified and in good working condition.
d. A working pressure of at least 30 psi.
e. Tested and certified pressure relief devices and valid test certificate.