Publications

TOTAL CFP Research and Development Department has developed powerful programs and methods for the analysis of bottom hole assembly behaviour in rotary drilling.The BHA 2 two-dimensional program, has thoroughly and successfully been used for studies of deviation problems and BHA design in TUNISIA, FRANCE, ALGERIA and ABU DHABI.We have built a correlation method based on the program results and the post-analysis of directional data gathered on site. This methud makes it possible to predict the inclination behaviour of a two stabilizer type of BHA.Correlations may be obtained for other types of rotary assemblies if requested.The program results are now more comprehensive due to a plot program which clearIy shows how a given BHA deflects within a given hole and under given drilling conditions.The side-forces (efforts exerted at the bit and at every BHAIhole contact) are comprehensively drawn.The influence of every-single parameter can be taken individually into account.Plots of the side-forces as a function of :- hole angle,- hole curvature,- weight on bit,- stabilizers undergauge (or wear),- DC's O.D. and DC's inertia,- BHA geometry- hole overgauge,- etc.can be obtained whatever the BHA and the hole conditions that are considered.This paper presents CFP's progrsms and methods based on successful operation applications:1 )Optimization of pendulum assemblies for enhanced hole vertically, W.O.B. and ROP.2) Follow-up of 5500 ft long, 6", deviated phase at 15 degree inclination.3) Optimization of lock-up BHA'S in 6", hole dril!ing.