Application of risk analysis in drilling well problems and operations- field case study

Abstract

The objective of this paper is to present specific drilling problems and their solutions, and then apply risk analysis for them. Drilling data for actual drilled wells and performing the risk analysis resulted in medium risk for the most operations done before starting the drilling process. Drilling well operations showed a various risky levels for operations. Formation problems that resulted from a constantly formation /fracture pressures curves may sometimes lead to not being able to select the casing setting depth CSD, and use high rate of penetration ROP without logging may provide a good results. The application of this method resulted in a proper selection of CSD for two drilling wells (I) and (II). In addition, the treatment of a large layer of shale formation X2 for well (I) was done by using common methods to prevent shale problems but these methods will add another 5-6 days to the number of drilling days. However, the proposed high ROP method, without logging, and with quick cementing and casing operations is almost perfect and leads in reducing the drilling hole days by 5-6 days for well (I), and that’s why the final drilling hole days will be 59 days instead of 65 days. Another real drilling well case which is suffering from a lot of well problems was controlled using suitable methods and the required mud additives to all geological sections safely drilled.