Analysis of stress field and determination of safe mud window in borehole drilling (case study: SW Iran)

Abstract

Having information on the magnitude and direction of stress in high depth is of critical importance in geology and engineering sciences. Of uppermost applicants of stress data in oil industry, determination of borehole stability can be mentioned. To achieve scientific and engineering solutions for problems such as optimal mud weight, stable routes, casing, sand production, etc., precise information on stress position in depth is required. So, the present study is aimed to determine magnitude and directions of in situ stresses in a borehole located in south western Iran. Minimum horizontal stress is observed along the direction of borehole breakout and maximum horizontal one, along the direction of derived from drilling. Direction of these two horizontal stresses is determined by means of image log. Position of in situ stresses in the under-study field is of normal stress regime. Having determined direction and magnitude of in situ stresses, we find safe mud window to design a stable borehole.