Abstract
This paper will illustrate the collaborative approach an international integrated oilfield service company used for planning a Drilling with Liner (DwL) operation to isolate a 6.5 ppge depleted sand interval in a deepwater block of Mississippi Canyon in the US Gulf of Mexico (GoM). Early collaboration between the service company and operator identified DwL technology as the core technology to meet the operator's well objectives. The DwL process allows a hazard interval to be isolated in a single trip resulting in less risk and wellbore exposure compared to the use of conventional drilling methods. Since DwL technology encompasses multiple engineering disciplines, these disciplines must be integrated in a seamless manner, and not be treated individually, to ensure the DwL objectives are met. To accomplish this, the service company formed a dedicated well engineering team to collaborate early on with the operator in their well planning process.
The technical disciplines identified to ensure the planned 9-7/8 -in_liner string reached its planned depth while also providing a secure wellbore over the entire life of the well included:
Torque, drag and hydraulics modeling of the liner running and drilling operation,
Connection cyclic fatigue analysis,
Directional tendency modeling
Casing cementation hardware
Formation drillability analysis
The aforementioned analyses and modeling resulted in the selection of optimum liner related equipment with the associated DwL procedures that would best deliver a high-integrity wellbore to the operator over the life of the well.
During the planning phase, regular operator-service company communications along with project scheduling software gave the operator assurance that agreed upon deliverables would be completed in the allotted time frame with the intended well objectives met. This paper will present the DwL planning process, description of mechanical and hydraulic concerns, and the associated risk assessment modeling to ensure that safety, environmental and DwL objectives were met.
