Using the well plan™ software model to determine the optimal hole cleaning to reduce mechanical pipe sticking in a Southern Iraqi oil field

One of the biggest problems that might arise during drilling operations is cleaning the hole or removing the cuttings from vertical and deviated wells. There are various factors that can contribute to an increase in non-productive time (NPT) and well costs, including but not limited to mechanical pipe sticking, lost mud circulation, difficulty running casing, bad cement jobs, and excessive torque and drag. In this study, a field case in the south of Iraq was conducted, and we constructed a hole cleaning model (Well Plan™ software model), calculated the minimum flow rate and cutting bed height to study the effects of all parameters (well inclination, mud density, mud rheological (yield point YP, plastic viscosity PV), drill pipe rotation speed RPM, penetration rate ROP, cutting density, and cutting size) on cutting transport. The results showed that when the well inclination, penetration rate, cutting density, and plastic viscosity are increased, the minimum flow rate will increase. Whereas when the fluid density, drill string rotation speed, and yield point are increased, the minimum flow rate will decrease. Also, in this well, mechanical pipe sticking occurs due to the actual flow rate needed to achieve the best hole cleaning being less than the minimum flow rate that was computed utilizing well Plan™ software. For instance, during run the LWD (Logging While Drilling) tools in the hole, at depth 3475m the pipe stuck occurs in the Zubair formation, the actual flow rate was 502 gpm while the minimum flow rate and the cutting bed height that are calculated from this model are 581 gpm and 1.27" respectively. Eventually, the research results can be utilized to support wells that are planned to be drilled nearby to the study region in the future.