OilVoice - AnTech’s MDET-S Detects Tool Joints in Risers with Special Sensors

AnTech’s MDET-S Detects Tool Joints in Risers with Special Sensors

Monday, July 27, 2009

AnTech Limited, a leading design engineering and manufacturing company serving the upstream oil and gas industry, announces it has designed a customised sensor system for a major oil service company for use in a well intervention operation being carried out offshore Louisiana in the Gulf of Mexico. The deepwater, high-pressure field is situated in over 6,000 feet of water, and is being developed using a permanently moored semi-submersible production and drilling facility.

Known as the Triple Sensor Tool Joint Detection System - or MDET-S, the new system is being used to detect tool joints in risers by measuring changes in magnetic fields that are triggered when a pipe joint passes through the field.

The new MDET-S was developed to improve the safety and efficiency of deploying tubing strings under pressure. To achieve this, AnTech’s client developed a hydraulic workover (HWO) system to support the deepwater GOM field. The system is located under the rig floor with heave compensation provided by the rig’s riser tensioning system. The HWO solution provides a high-strength conveyance method to intervene and operate under pressure from a floating vessel in deep, high pressure reservoirs. Special rig-assist HWO equipment, combined with a purpose-built BOP stack, are being used to deploy the tubing strings under pressure.

To ensure that this is carried out safely, the technician must know when the tool joints are correctly located within the BOP stack so that the joint can be passed through the set of pressure seals into or out of the well bore.

Traditionally, locating tool joints is carried out by painstaking manual measurement and careful positioning of the tubing string, in relation to a specific visual point well above the BOP stack. The objective was to replace this manual method with a device that could automatically detect tool joints and alert the technician when the joint had moved into the field of sensors.

Successful Track Record in Subsea Detection Systems
Given its 16-year history of developing and manufacturing magnetic wellhead sensors that assist deepwater operators to position specialist equipment on the seabed and detect the end of coiled tubing in a riser, AnTech was approached to formulate a solution.

To accommodate the magnitude of the new GOM installation, AnTech expanded the number of sensors from two to six, and upgraded the existing ATEX certification.

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