INTEC has worked with a variety of completion and workover riser systems, including:

• A simple deepwater dual-tubing riser system;
• An early-generation composite workover/completion riser system (originally made for Placid); and
• An ultra-deepwater riser study to select a system for Shell Offshore, Inc.

The simple deepwater dual-tubing riser system was designed to minimize cost by utilizing a simple combination of two tubing strings for a riser. This system was used successfully in a 2,080 ft water depth in the Mississippi Canyon 401/445 Development for ORYX. It worked in conjunction with 5-inch drill pipe for running and retrieving the subsea tree.

For another recent deepwater project, the original Placid workover system was rented by an INTEC client for installation of subsea completion and tree in a 1,750 ft water depth. This project required the use of INTEC expertise to coordinate the complete refurbishment, testing and handling of this early generation workover riser system, both onshore and offshore.

INTEC performed a tree and riser options installation study for Shell Offshore, Inc. to determine the most suitable completion riser system necessary for SOI's future deepwater needs. The first objective of the study was to define the preferred subsea tree, completion riser and workover control system configurations necessary for the Mensa project.

Requirements included:

• System capability for 2,000 ft to 6,000 ft water depth range
• Production tubing capability of greater than 4-inch completions
• Compatible with future DP drillship installations