Published April 2010
The prevention of the geological problems while well drilling on Beyimdagh-Tekchay raise
M.H.YusifovIn the paper are studied the geological conditions and reasons of problems occurred in well drilling on Beyimdagh-Tekchay area. Analysis of the collected geological data show that on Beyimdagh-Tekchay area while drilling Barrem lower part beds and hoterive stage the collapses take place in the results of which occur breakage and collapses, gas ingress and also drilling fluid losses while drilling of Valanjin beds and upper part of the Middle Yura. One of the problem appearance factors in the dislocation zone of uplift and near uplift part of the structure is the presence of curve angles of beds occurring and rocks breaking. In order to avoid problems while new drilling on Beyimdagh-Tekchay area taking into account rocks lithological composition and tectonic structure it is necessary to prevent the sharp difference between formation and borehole pressures and to mark out the combined zone of drilling conditions. In order to achieve it, problem dependence from lithological-stratigraphic and tectonic reasons along stratigraphic complexes were analyzed, peculiarity of well drilling conditions is studied. The used drilling fluids density analysis has been carried out and combined pressures graph was developed on the basis of calculated data of formation pressure and hydrofracturing pressure according to areas. The drilling fluid density along depths and sections have been selected according to combined pressures graph for well designing. Due to different problems in drilling the number of casing strings is determined, zones differing formation pressures and hydrofracturing pressure are marked out, also well lining zone along section intervals are recommended.
