Study of Faults in Asmari Formation by FMI Image Log, Case Study: Lali Oilfield

Document Type: Original Article


1 Abadan Institute of Technology, Petroleum University of Technology, Abadan, Iran

2 Ahwaz Faculty of Petroleum Engineering, Petroleum University of Technology, Ahwaz, Iran


Identification and description of faults in an oilfield will help to prevent problems such as casing collapse, wellbore
instability, and hydrocarbon leakage. One way to study the performance of faults is using formation micro imager
logs. This type of log does this by fully imaging the wellbore wall. In this study major and minor faults were
recognized and assessed through analyzing raw data by means of GEOFRAME
® software at interval of 1816-2050
m in well Lali-26. Abrupt change of bed dip direction from southwest to northeast at 1816 m showed that there is a
fault originated from over thrusting Asmari formation on Gachsaran formation. Furthermore there are several minor
faults at deeper than 1845 m, which were mainly identified by lithology contrast. All of studied faults had E-W
trend. The minor faults may be caused by compression of lower block in main fault.