An operator developing gas wells in the Appalachian Basin was using containment well cellars to enable production trees to be completely below grade or tubing heads to be just below grade.
The operator experienced several hours of operational NPT when installing the surface casing and wellhead housing. Many of the delays were caused by cellar spacing constraints that restricted access of the third-party welding vendor to critical areas for performing a proper welding job of the surface casing to the wellhead housing connection. In addition to concerns with installation integrity, the safety risk was elevated by the restricted work environment.
To solve this challenge, SLB provided the operator with the Cameron Adapt NST nested multistage compact wellhead system with a threaded landing mandrel box for the bottom casing connection. The compact design of the Adapt NST system saves operators time and cost, in comparison to using traditional wellheads, by enabling efficiently landing multiple casing strings within one system.
By incorporating the threaded landing mandrel, the operator was able to land the surface casing into the well without the need to perform any welding operations, eliminating the requirement for the third-party vendor operation and the elevated level of HSE risk. The operator also gained additional operational time savings through the ability to install a wellhead housing that had been fully tested and assembled prior to installation.
To date, the operator has installed more than 40 Adapt NST wellhead systems on its unconventional pads in the Appalachian Basin, saving a total of 165 hours of potential NPT and significantly lowering exposure risk for the personnel on location.
