Abstract
This paper will compare the operational performance of appraisal / exploration wells in the East Timor Sea for a Joint Venture Group. The paper will review operations using three different rigs; one semi-submersible and two jack ups, each deploying a different wellhead configuration / method to drill exploration / appraisal wells in the same field.
A review of the performance improvements progressed by the operations team over the three years of the staggered project will be provided including;
Field breaking records for drilling performance
Comparison of motor and RSS systems with tricone and PDC bits in the field
The use of a vibration dampening tool to effect drilling performance
BOP and riser running operations compared between the three different rigs
Sidetracking operations along with recommendations
Three operational phases were focused upon during the review and these were; drilling 17.1/2" and 12.1/4" hole sections along with open hole sidetracking operations. Drilling performance, engineering planning lessons and recommendations are captured in this paper. A brief review of the costs of deviated wells utilizing subsea wellheads deployed from a semi-submersible rig in comparison to directional wells utilizing subsea wellheads deployed from a jack up, and deviated subsea wells utilizing surface wellheads will be overviewed as there is minimal comparison of these operations currently available in the literature.
The lessons and recommendations contained within this paper can be applied during the well planning stage of any project. A detailed review of performance has been undertaken which highlights the importance of the planning process in operational optimization along with the necessity of clearly defining the expected well outcome as a means of managing the economic success of a project.
