Control and injection lines are fed through the MCLRS custom guides, eliminating any manual manipulation of lines prior to clamping.

On deepwater wells, non-productive time (NPT) can approach 40% of total rig time. One effective approach to eliminating the potential for serious downtime in offshore and deepwater well completions while also enhancing safety and operational efficiency is to use purpose-designed, single-source technological services such as Tesco Corp.’s patented Multiple Control Line Running System (MCLRS).

Using a conventional slip handling system during the course of a multiwell deepwater subsea completion project increases the chances for control lines
to be cut or damaged.

Damage to control lines usually results from human error such as closing the slips unintentionally. The most common reason for damage to control lines originates from the clamp being lowered and drawing the slip bodies onto the control lines. In contrast, the MCLRS handles control lines without first passing them through the slips, eliminating the possibility of damage that can result in NPT.

Any failure or leak from a control or injection line results in either a data or function loss. Repairs to control lines during the tubing running operation are not an acceptable practice. Furthermore, splices to control lines are not always reliable. Any control line that has been cut or crimped and which fails after the well has been completed requires mobilizing an expensive deepwater rig back to location for an intervention. Once the control lines are installed into the guide, the human element has been removed. No manual manipulation of control lines is necessary during pipe makeup or cross-coupling clamping.

The technology
System technology consists of a raised platform that elevates the slips 6 ft (1.8 m) above the rig floor, providing unrestricted access to the tubing string below the slips. Control lines feed through the open platform sides without having to pass through the slips and are clamped to the tubing string below the slips in a window, usually referred to as a “false rotary.” This window provides cross-coupling clamping personnel their own space on the floor to stage clamps and tools for use.
Tongs and floor personnel are moved to the basket above the MCLRS window. All tong operations and pipe stabbing are done in the basket. Personnel remotely operate tongs and control line guides, further improving safety.

Completion tubular running speeds largely depend on the rig’s configuration. Many deepwater rigs today are designed for efficiency while drilling wells but not necessarily for efficiently completing them. In fact, the majority of the applications of the system in deepwater projects have been on rigs that have never seen completion equipment onboard. Typical running speeds range between 10 and 18 joints per hour. Although running speeds are important to controlling costs, doing it safely is still a primary focus.
Using the system allows for control line reels to be placed and only passively monitored. This process further eliminates the need to input slack in order to clamp or make up the next joint of tubing. Instead, control lines are run through hydraulic guides that mechanically position the lines in the proper location for ease of clamping. The ability to handle control lines mechanically keeps them out of harm’s way and makes manual line manipulation a thing of the past.

Safety enhancements

The system eliminates the sheave overhead that is normally used to handle control lines. Crew members are no longer required to harness up for a ride in the derrick.
The entire package makes simultaneous operations possible and decreases the time necessary for rig-up to less than two hours. Each lift is preassembled and broken into three segments. The first lift is composed of the lower base plate, which functions as the foundation. The second lift is the system upper base section with preinstalled slips and control line guides. The final lift to the rig floor consists of a basket that contains the tongs and a remote control panel. Once the hydraulics are connected, the system is ready to go.

Separation of the tubing makeup and clamping stations into two physically segregated areas improves safety without reducing running speed. Vertical segregation of workstations separates the pipe running function from the control line clamping function so that each crew can safely and efficiently complete its task. Each control line is fed through a hydraulically positioned guide, which aligns the stiff control line with the tubing string. Multiple control lines are pushed firmly but gently against the tubing in preparation for clamping to the tubing string. The clamping crew places recessed clamps around the tubing and control lines and bolts the clamps together to hold the lines firmly against the tubing string. The clamping crew operates in its own designated workspace, decreasing any cross-contamination of services.

The tong crew adds joints of tubing to the tubing string in the station above the clamping crew. During this process, the tubing string is held in slips mounted above the clamping workstation. The remotely operated tubing tongs require only two crew members in the tubing makeup area.

Control line protection also extends to rig-down. The procedure involves carefully lowering extra control lines temporarily into the well bore during rig down. Once the system has been rigged down, workers remove the temporary joint and extra control line and make the final terminations to the hanger. At this point a next-generation sliding slip system is employed to handle the umbilical cable. The sliding slip system is remotely operated and designed to protect the umbilical cable and minimize extra personnel to install the clamp.

Case study

In one deepwater project, Petrobras America completed two gas condensate intervals in two subsea wells, Garden Banks 244 #2 and #3. The wells incorporated smart well technology including downhole gauges and hydraulic sliding sleeves to enable the operator to choose which of the completed intervals would be produced.

The project’s objectives were to install 15,500 ft (4,727.5 m) of control lines and completion tubing (41?2-in., 15.5# 13 Cr-110 BTS-6 Range III); eliminate the chance of slips cutting or damaging the six control lines and single electrical conductor; and provide a safe and efficient work environment to install the SmartWell surface controlled subsurface safety valve (SCSSV), chemical injection, control lines and cross-coupling control line protector clamps.

The system was rigged up in about two hours, with the company providing handling and support equipment. The tongs and slips placed above the rotary provided a separate work area on the small rig floor for the tool specialists and the installation equipment. The crew ran 12 to 15 joints of tubing per hour. The control lines were installed efficiently and safely.