Designing a cement program for Extended Reach Drilling well using Landmark software

Extended-Reach Drilling (ERD) is essentially an advanced form of directional drilling. ERD employs both directional and horizontal drilling techniques and has the ability to achieve horizontal well departures and total vertical depth-to-horizontal distance ratios well beyond conventional directional drilling. Acceptable production from horizontal well needs successful drilling and completion operation. Hence, cementing of an ERD and horizontal well is an essential part of completion and it influences the future production from the well. Designing proper cement program which is compatible with formation conditions is one of the most significant factors for a successful cement job.
This study aims on two problematic parameters of cementing in ERD well. The main objectives of the study is designing cement program which can prevent the presence of the mud channeling on the lower side of the annulus and the water channeling on the opposite side which is top part of the annulus during the casing cementing operation. The study of research papers and other related works showed that creation of turbulent flow regime of pumped cement slurry in the annulus is the best way to remove the settled mud in the lower side of the annulus. Turbulent flow behavior breaks the mud gel and acts as a pushing force for the removal of settled particles from mud. As for the water channeling, the presence of it is mostly affected by the free water content of the cement as the research papers claim. Thus the maintaining the percentage of free water content in cement slurry must be minimum and close to zero.
Through my research and studies I try to resolve those problems by designing the suitable cement program. Calculations were made with Excel Macros spreadsheet results. Overall data was used in OptiCem module to simulate and observe casing cementing procedures. The main concern during cementing operation found out to be ECD, which is highly affected by the flowrate of pumping. Critical flowrate values showed very similar results from both of the ways of obtaining the results, OptiCem and Excel Macros. Overall studies showed that proper flowrate only is not enough for creating turbulent flow and that ECD’s high values on higher flowrates disable us to reach the turbulent flow regime without breaking the formation due to fracture gradient’s reaching.