DESURV: An ANSI C program for borehole desurvey calculation by local least-squares fitting

N. Kuka and Arben Shtuka and Jean-Jacques Royer. ( 1994 )
in: Computers \& Geosciences, 20:6 (919-960)

Abstract

Several methods have been suggested to solve the problem of borehole desurvey calculation, but the least-squares seems to be one of the best approximations to reality. Because the least-squares solution is susceptible to roundoff errors, especially if high powers of the downhole distance are used, two approaches are highly recommended: (1) using orthogonal instead of standard polynomials, and (2) applying the method locally to small regions down the hole. Such procedures provide accurate modeling of the borehole curve, even in the situation of deep and complicated boreholes. An interactive ANSI C computer program is provided to implement the proposed procedure. Considerable control can be exercised by the user in selecting and modifying the model parameters. Graphic displays make it easy to evaluate the data and the model. After adequate fitting of the borehole curve is achieved, the sample coordinates are computed and stored in an ASCII file. Deviations from design position also are computed at the surveyed points and are stored for any further statistical or geostatistical analysis. The local least-squares fitting with Chebyshev polynomials can be extended to gridding of unit vector fields in one, two, or three dimensions.

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BibTeX Reference

@article{kuka:hal-04026767,
 abstract = {Several methods have been suggested to solve the problem of borehole desurvey calculation, but the least-squares seems to be one of the best approximations to reality. Because the least-squares solution is susceptible to roundoff errors, especially if high powers of the downhole distance are used, two approaches are highly recommended: (1) using orthogonal instead of standard polynomials, and (2) applying the method locally to small regions down the hole. Such procedures provide accurate modeling of the borehole curve, even in the situation of deep and complicated boreholes. An interactive ANSI C computer program is provided to implement the proposed procedure. Considerable control can be exercised by the user in selecting and modifying the model parameters. Graphic displays make it easy to evaluate the data and the model. After adequate fitting of the borehole curve is achieved, the sample coordinates are computed and stored in an ASCII file. Deviations from design position also are computed at the surveyed points and are stored for any further statistical or geostatistical analysis. The local least-squares fitting with Chebyshev polynomials can be extended to gridding of unit vector fields in one, two, or three dimensions.},
 author = {Kuka, N. and Shtuka, Arben and Royer, Jean-Jacques},
 doi = {10.1016/0098-3004(94)90036-1},
 hal_id = {hal-04026767},
 hal_version = {v1},
 journal = {{Computers \& Geosciences}},
 month = {July},
 number = {6},
 pages = {919-960},
 publisher = {{Elsevier}},
 title = {{DESURV: An ANSI C program for borehole desurvey calculation by local least-squares fitting}},
 url = {https://hal.univ-lorraine.fr/hal-04026767},
 volume = {20},
 year = {1994}
}