TY - THES

T1 - Level 3 Casing Drilling in a Mature Field Environment

AU - Ndiga Ngue, Joseph Patrick

N1 - embargoed until 03-09-2020

PY - 2018

Y1 - 2018

N2 - The drilling industry is continually searching for new technology and engineering advancements to improve drilling efficiency at the lowest cost. Drilling-with-Casing (DwC) is one of these new technologies which has been utilized to mitigate drilling hazards such as wellbore instability, lost circulation and eliminating problematic surge and swab effects seen with conventional drilling methods. Most of the current DwC activities are focusing on drilling vertical wells, but recently interest in Drilling-with Casing in directional wells, which is by definition the Level 3 casing drilling system has drastically increased as the process for drilling straight holes become proven, and more tools are becoming available. This work describes, analyses and evaluates the Level 3 casing drilling in a mature field environment like the Vienna Basin by means of solving the problems encountered by OMV Austria in the borehole conditions during check trips where lose of time and money occurred In the first part, history of casing drilling system, casing drilling applications, casing drilling types and operations are presented in order to see the development and the evolution of casing drilling technology to date. The thesis then focuses on screening the market for available Level 3 casing drilling technology. Schlumberger and Weatherford technologies were chosen and the screening included offset data analysis of existing projects. Furthermore, a combination of technical and economic feasibility was evaluated to implement the Level 3 casing drilling in the Vienna Basin. For this, the boundary conditions within OMV Austria were set by the selection of a conventional well, E3. The economic feasibility study was performed for the cost estimation and control using the probabilistic approach. The comparison of the results of the simulations of E3, Weatherford and Schlumberger led to the possibility to apply the Level 3 casing drilling in the Vienna Basin. The Under Reamer (UR) arms design needed to be improved by modifying the gauge protection and exposed cutting area. The Bottom Hole Assembly (BHA) specially designed with a motorized Rotary Steerable System (RSS) will provide a smooth well profile with minimal well tortuosity that could affect casing fatigue life and therefore, fewer torque requirements and casing connections. Proper logistics and planning are also central to an outstanding casing directional drilling operation.

AB - The drilling industry is continually searching for new technology and engineering advancements to improve drilling efficiency at the lowest cost. Drilling-with-Casing (DwC) is one of these new technologies which has been utilized to mitigate drilling hazards such as wellbore instability, lost circulation and eliminating problematic surge and swab effects seen with conventional drilling methods. Most of the current DwC activities are focusing on drilling vertical wells, but recently interest in Drilling-with Casing in directional wells, which is by definition the Level 3 casing drilling system has drastically increased as the process for drilling straight holes become proven, and more tools are becoming available. This work describes, analyses and evaluates the Level 3 casing drilling in a mature field environment like the Vienna Basin by means of solving the problems encountered by OMV Austria in the borehole conditions during check trips where lose of time and money occurred In the first part, history of casing drilling system, casing drilling applications, casing drilling types and operations are presented in order to see the development and the evolution of casing drilling technology to date. The thesis then focuses on screening the market for available Level 3 casing drilling technology. Schlumberger and Weatherford technologies were chosen and the screening included offset data analysis of existing projects. Furthermore, a combination of technical and economic feasibility was evaluated to implement the Level 3 casing drilling in the Vienna Basin. For this, the boundary conditions within OMV Austria were set by the selection of a conventional well, E3. The economic feasibility study was performed for the cost estimation and control using the probabilistic approach. The comparison of the results of the simulations of E3, Weatherford and Schlumberger led to the possibility to apply the Level 3 casing drilling in the Vienna Basin. The Under Reamer (UR) arms design needed to be improved by modifying the gauge protection and exposed cutting area. The Bottom Hole Assembly (BHA) specially designed with a motorized Rotary Steerable System (RSS) will provide a smooth well profile with minimal well tortuosity that could affect casing fatigue life and therefore, fewer torque requirements and casing connections. Proper logistics and planning are also central to an outstanding casing directional drilling operation.

KW - Drilling-with-Casing (DwC)

KW - Retrievable BHA system

KW - Directional drilling

KW - Drilling-with-Casing (DwC)

KW - Abrufbares BHA-System

KW - RichtBohrung

M3 - Master's Thesis

ER -