calculo de lechada de cemento en pozo
TRANSCRIPT
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7/29/2019 Calculo de Lechada de Cemento en Pozo
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Well information:
Well is drilled with 8.5 inch bit to 9,015 MD/8,505 TVD with oil based mud(9.5 ppg). Estimated
hole sized based on an open hole log is 8.6 inch.
Previous casing size is 9-5/8 and its shoe is at 6,500 MD/5000TVD.
Plan to run 7 casing and planned shoe depth at 9,000MD/8,500TVD.
There is one float collar at 8960MD/8470 TVD.
Top of cement is 2000 ft above 9-5/8 casing.
Spacer volume is from top of cement to surface.
Casing information
7 casing ID = 6.185
9-5/8 casing ID = 8.85
Use hole size measured from the open hole log to determine cement volume.
The well schematic should look like this.
http://www.drilling-mud.org/category/oil-based-mud/http://www.drilling-mud.org/category/oil-based-mud/http://www.drilling-mud.org/category/oil-based-mud/http://www.drilling-mud.org/category/oil-based-mud/ -
7/29/2019 Calculo de Lechada de Cemento en Pozo
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Determine the following items:
Cement volume
Spacer volume
Displace volume
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As per the cement program, the final schematic will look like this.
Determine cement volume
Total cement volume = cement in the annulus between open hole and 7 casing + cement in
annulus between 9-5/8 casing and 7 casing + cement in shoe track
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There are three parts that you need to calculate in order to get total cement volume as listed
below:
1. cement in the annulus between open hole and 7 casing
2. cement in annulus between 9-5/8 casing and 7 casing
3. cement in shoe track
The cement volume is based on annular capacity multiplied by cement length of each section.
Cement in the annulus between open hole and 7 casing
Annular capacity between open hole and 7 casing = (8.62-7
2) 1029.4 = 0.02425 bbl/ft
Length from 7 casing shoe to 9-5/8 casing shoe = 9000 6500 = 2500 ft
Cement in the annulus between open hole and 7 casing = 0.024252500 = 60.6 bbl
Cement in annulus between 9-5/8 casing and 7 casing
Annular capacity between 9-5/8 casing and 7 casing = (8.852-72) 1029.4 = 0.02849 bbl/ft
Length of cement inside 7 casing = 2000 ft
Cement in annulus between 9-5/8 casing and 7 casing = 0.02849 x 2000 = 57 bbl
Cement in shoe track
Capacity of 7 casing = 6.1852
1029.4 = 0.03716 bbl/ft
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Shoe track length = 40 ft
Cement in shoe track = 40 x 0.03716 = 1.5 bbl
Total Cement Volume
Total cement = 60.6 + 57 + 1.5 = 119.1 bbl
Determine space volume
As per the cement program, spacer will be at surface.
Spacer volume = Annular capacity between 9-5/8 casing and 7 casing x length of spacer
Annular capacity between 9-5/8 casing and 7 casing = (8.852-7
2) 1029.4 = 0.02849 bbl/ft
Length of spacer = volume annulus to TOC
TOC 2000 ft inside casing shoe = 6,500 2,000 = 4,500 ft
Spacer volume = 0.02849 x 4,500 = 128.2 bbl
Determine displace volume
The displacement volume is from surface to the float collar where the top plug will sit on.
Displacement volume = Capacity of 7 casing x Length to the float collar
Capacity of 7 casing = 6.1852
1029.4 = 0.03716 bbl/ft
Length to the float collar = 8,960 ft
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Displacement volume = 0.03716 x 8960 = 333 bbl
Conclusion for this cement calculation
Cement volume = 119.1 bbl Spacer volume = 128.2 bbl
Displace volume = 333 bbl
With this example, I wish you would understand more about how to determine cement volume.
Please remember that any cement volume calculation is based on this concept.