Buchan Oil Field - Drilling

Drilling

BP had to employ sophisticated measures to overcome the field's geological difficulties. These problems were significant enough that the project's two senior engineers published a paper about them in the Society of Petroleum Engineers. They faced problems with the project timing, with the operational drilling of the well, and with the completion phase (Pinchbeck 1979).

The lack of suitable geophysical data on the reservoir required serious precautions. The well was designed to have numerous backups to ensure that if the reservoir top was penetrated accidentally that the casing strings would be able to handle the overpressure. There was also the problem of the encountering other loss zones such as those experienced by the appraisal wells, which was overcome through a combination of strict control of the drilling and its location, along with careful analysis of the various geological variables. This ensured that the correct-sized wells were drilled through the loss zones and that the over-pressured shales were avoided by careful monitoring of the pore pressure. In total nine wells were drilled for production (seven central wells and two satellite wells).