TY - THES

T1 - Assessing the Feasibility and Effectiveness of Reverse Circulation in Drilling Operation

AU - Stanic, Tomislav

N1 - no embargo

PY - 2023

Y1 - 2023

N2 - Hole cleaning and cement quality improvement are considered some of the challenges facing energy extraction companies, especially for horizontal wells. One of the solutions proposed a decade ago to overcome these issues was Reverse Circulation (RC). Reverse Circulation has been implemented in many industries, and it has been proven to be a promising method with the potential to significantly increase drilling efficiency while reducing total drilling costs. In Reverse Circulation, drilling fluid is pumped from the surface into the annulus, where it then flows to the base of the wellbore. Cuttings from the formation are then transported back to the surface through the inside of the drill string. Despite numerous successful studies published on the utilization of RC for various purposes, there remains a common deficiency in the majority of these works. The limitations of applying this method and the necessary requirements are often inadequately explained. Therefore, the ultimate goal of this thesis is to look into the many uses of RC, including drilling, cementing, and hole-cleaning processes. In addition, it will highlight the unique challenges of RC drilling and point out the significance of comparing this technology against conventional approaches. The primary focus of this thesis is to explore the benefits and drawbacks of RC drilling, particularly in the context of fluid mechanics, limitations, applicable scenarios, and economic implications. Additionally, the thesis undertakes a comparative analysis of hole cleaning efficiency between Reverse Circulation and conventional circulation by constructing scenario cases using the eDrilling simulator. To conduct a fair comparison between the two methods, two Key Performance Indicators (KPIs) were employed: cuttings profile and cuttings transport rate. The performed case studies revealed that under lower or equivalent pressures, conventional circulation outperformed Reverse Circulation in terms of cuttings transport efficiency. However, with appropriate input adjustments, the best-case scenario for Reverse Circulation matched or even exceeded the performance of conventional circulation, demonstrating that the Reverse Circulation process can be optimized for more effective cuttings removal and wellbore stability.

AB - Hole cleaning and cement quality improvement are considered some of the challenges facing energy extraction companies, especially for horizontal wells. One of the solutions proposed a decade ago to overcome these issues was Reverse Circulation (RC). Reverse Circulation has been implemented in many industries, and it has been proven to be a promising method with the potential to significantly increase drilling efficiency while reducing total drilling costs. In Reverse Circulation, drilling fluid is pumped from the surface into the annulus, where it then flows to the base of the wellbore. Cuttings from the formation are then transported back to the surface through the inside of the drill string. Despite numerous successful studies published on the utilization of RC for various purposes, there remains a common deficiency in the majority of these works. The limitations of applying this method and the necessary requirements are often inadequately explained. Therefore, the ultimate goal of this thesis is to look into the many uses of RC, including drilling, cementing, and hole-cleaning processes. In addition, it will highlight the unique challenges of RC drilling and point out the significance of comparing this technology against conventional approaches. The primary focus of this thesis is to explore the benefits and drawbacks of RC drilling, particularly in the context of fluid mechanics, limitations, applicable scenarios, and economic implications. Additionally, the thesis undertakes a comparative analysis of hole cleaning efficiency between Reverse Circulation and conventional circulation by constructing scenario cases using the eDrilling simulator. To conduct a fair comparison between the two methods, two Key Performance Indicators (KPIs) were employed: cuttings profile and cuttings transport rate. The performed case studies revealed that under lower or equivalent pressures, conventional circulation outperformed Reverse Circulation in terms of cuttings transport efficiency. However, with appropriate input adjustments, the best-case scenario for Reverse Circulation matched or even exceeded the performance of conventional circulation, demonstrating that the Reverse Circulation process can be optimized for more effective cuttings removal and wellbore stability.

KW - Reverse Circulation

KW - Pressure Profile

KW - Cuttings profile

KW - Cuttings transport rate

KW - Conventional circulation

KW - Reverse Circulation

KW - Druckprofil

KW - Bohrkleinprofil

KW - Bohrkleintransportrate

KW - Konventionelle Zirkulation

U2 - 10.34901/mul.pub.2024.006

DO - 10.34901/mul.pub.2024.006

M3 - Master's Thesis

ER -