Restivehorse
Petroleum
- Jun 16, 2023
- 6
I am in the process of creating a cosine curve for the settlement survey in accordance with API 653 annex B.2.2.4 and B2.2.5. I have read through the entire annex and am pretty understanding of it, though cannot seem to understand how to acquire appropriate predicted elevations.
In API 653 it says: Where Elevpred is the elevation predicted by the cosine curve at angle theta. A typical starting point for a computer
best-fit cosine curve is a least-square fit where a, b, and c are chosen to minimize the sum of the square of the
differences between measured and predicted elevations.
However, no where in the code does it specify what R2, a , b, and C values area derived from?
R2 ≥ 0.9
Elevpred = a + b × cos (theta + c)
Can anyone help me to get R2, a , b, and c values in excel sheet attached below:
Tank parameters and elevation (height) value of tank observation is shown in excel file attached
Thanks
In API 653 it says: Where Elevpred is the elevation predicted by the cosine curve at angle theta. A typical starting point for a computer
best-fit cosine curve is a least-square fit where a, b, and c are chosen to minimize the sum of the square of the
differences between measured and predicted elevations.
However, no where in the code does it specify what R2, a , b, and C values area derived from?
R2 ≥ 0.9
Elevpred = a + b × cos (theta + c)
Can anyone help me to get R2, a , b, and c values in excel sheet attached below:
Tank parameters and elevation (height) value of tank observation is shown in excel file attached
Thanks