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Mud requirement & Barite requirement for Offshore drilling
20 August 2019
Is there any thumb rule to calculate the mud requirement for Offshore Deepwater Drilling and what is the amount of barite contingency required for well control operation.
4 answer(s)
ADunsmuir
Mud Engineer
MI-Swaco
Total Posts: 4
Join Date: 10/11/16

Totally agree with the response form Steve. I have been on projects where the minimum requirement has been tonnage and 100 mt seems to be a favourite and also on projects where it is a unit of weight increase. On one of those projects the operator's procedures required a 0.5 ppg increase and the drilling contractor's procedures had a full 1.0 ppg rise. Ensure that the calculation is for a full circulating system (active pit, hole volume, flowline and sandtraps) and use the maximum fluid density expected for the section in question as the starting weight for the calculation if using a weight unit increase. Make sure that you take into account any potential dead volume in the Barite silos and remember that this calculation is your minimum contingency volume not the overall requirements for weighting material for the section in question.

As already highlighted drilling fluid requirements in exploration wells have greater unknowns over development wells where a reasonably accurate dilution factor can be determined. As with all wells much depends on the type of formation that is being drilled, the size of the drill cuttings (a volume of smaller cuttings has an overall larger surface area than the same volume of larger cuttings therefore more mud/volume of cuttings is lost), washouts, faults/fractures.


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himansh1990
Technical Executive
Jubilant Enpro Private Limited
Total Posts: 17
Join Date: 25/09/13
Thank You Steve & Peter.

And waiting for your additional replies and documents - Peter.
Companyrep
Drilling Specialist/Well Engineer/Training Consultant
Kingdom Drilling
Total Posts: 461
Join Date: 10/01/05

Yes lots.

ill look in my archives and attach some docs spreadsheets etc that should be of use when I am able to access my files in a few days time.

on the road at the mo!


snas
Well Engineering Consultant and Instructor
SPREAD Associates
Total Posts: 38
Join Date: 23/03/16
Himanshu

Barite contingency requirements vary with different operating companies.

Some operators have a minimum stock of 100 Tons whilst others have a requirement to have a minimum Barite quantity to increase the mud weight of the complete circulating system by 0.5 ppg or 1.0 ppg. 

Minimum stock levels of Barite, Cement, Drillwater, and Diesel are normally defined by the Operator and the Drilling Contractor.
It all depends what is being drilled, an exploration well has much bigger uncertainties compared to drilling development wells.
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