A drilling optimization method; A case study in wells of one oil eld of Iran

This paper perform a study on 17 ½” hole section of 7 wells in one of the biggest oil field of Iran which has common resources with adjacent countries. Decreasing duration of drilling and completion of wells is one of the important goals of the oil company and subsequently drilling operators. In wells of area, 17 ½” hole section typically is a 1100m to 1300m interval and consumed as an average 18 to 28 days to be drilled in previous drilled wells. An experimental method based on gathering facts, finding out causes and using lesson learnt of first phase wells of one drilling operator, was applied to decrease time of drilling in second phase wells. Finding out the cause of low ROP of 4 first wells such as low flow rate, bad hole condition, low WOB and not compatible bit lead us to appropriate changes in 3 next wells as Improving solid control system, providing enough flow rate, making better condition for drilling fluid, using packed hole assembly BHA and better bit selection. More ROP and less cost per meter are the result of implementing this method. Moreover a study should be done for choosing more appropriate type of PDC bits which can drill same as or better than rock bits in this hole section.