Analysis of complications in construction of controlled directional producing wells in Eastern-Siberian accumulations
The article is dedicated to complications in 40 controlled directional wells drilled at one of the Eastern- Siberian accumulations. The analysis excluded complications of the well vertical spacing, blocked off by the conductor.Most of complications (37.7 %) while drilling controlled directional wells occur when the azimuth of drift coincides with a direction of North-East diagonal system of planetary fissuring, which also coincides with the direction of maximum horizontal stress (30°…60°). High percentage of complications (30.5 %) was marked while drilling wells within sublatitudinal system of planetary fissuring. The fewest number of complications (7.6 %) was noted while drilling wells with the azimuth outside the system of planetary fissuring.The largest number of the complications is most likely to be caused by the undertreatment of controlled directional and horizontal spacing of wells. That creates conditions for increase of depression in a well while a borer is being lifted and leads to bridges, rockslides and afterflows.The lack of comprehensive data in provided hydrodynamic studies of producing wells does not allow making an objective estimate of the influence of the azimuth of the drift in producing horizon on well delivery. However, authors can suppose that if the technology of the horizontal spacing drilling is developed and complications are reduced, the wells oriented in the direction of the diagonal North-East and orthogonal sublatitudinal East-West systems of planetary fissuring will be the most efficient.