METHODS  OF  DEVELOPMENT  OF  PROGRAMS  FOR  CALCULATION  OF  WELL  PROFILE  AS  A  CURVE  OF  CONSTANT  CURVATURE  AS  EXEMPLIFIED  BY  A  SYMMETRICAL  BICLOTHOID

I.L. Barsky – Ph.D. in Physics and Mathematics, Leading Research Associate
A.B. Levina – Ph.D. in Physics and Mathematics, Academic Secretary
B.R. Lalayants – Postgraduate Student
R.V. Ivanychev – Head of Department
P.A. Makarov – Head of Department
OJSC NPO “Burovaya Tekhnika”

The growing  complexity of geological and technological tasks to be solved  for selection of the profile of directional and horizontal wells determines creation of advanced scientific-methodological approaches to well profile design. The article provides the rationale for designing of a profile with constant curvature according to the natural curvature of a drill string or a casing. The method is based on the use of the so-called natural equation of a curve that shows functional relationship between the curvature of the curve,  arc length and the actual borehole depth. The authors provide an Excel format solution for the geometry of the projected well profile as a symmetrical biclothoid. The solution allows to reduce the bending stress of   the string in the wellbore, the friction force during drilling tool pulling and running, and to ensure stable weight on bit.

Key words: curvature; curve; deviation intensity; circle equation; clothoid; biclothoid; three interval profile.

METHODS  OF  DEVELOPMENT  OF  PROGRAMS  FOR  CALCULATION  OF  WELL  PROFILE  AS  A  CURVE  OF  CONSTANT  CURVATURE  AS  EXEMPLIFIED  BY  A  SYMMETRICAL  BICLOTHOID

I.L. Barsky – Ph.D. in Physics and Mathematics, Leading Research Associate  
A.B. Levina – Ph.D. in Physics and Mathematics, Academic Secretary
B.R. Lalayants – Postgraduate Student
R.V. Ivanychev – Head of Department
P.A. Makarov – Head of Department
OAO NPO “Burovaya Tekhnika”

The growing  complexity of geological and technological tasks to be solved  for selection of the profile of directional and horizontal wells determines creation of advanced scientific-methodological approaches to well profile design. The article provides the rationale for designing of a profile with constant curvature according to the natural curvature of a drill string or a casing. The method is based on the use of the so-called natural equation of a curve that shows functional relationship between the curvature of the curve,  arc length and the actual borehole depth. The authors provide an Excel format solution for the geometry of the projected well profile as a symmetrical biclothoid. The solution allows to reduce the bending stress of   the string in the wellbore, the friction force during drilling tool pulling and running, and to ensure stable weight on bit.

Key words: curvature; curve; deviation intensity; circle equation; clothoid; biclothoid; three interval profile.