Many active service vessels are equipped with Dynamic Positioning (DP); a computer controlled monitoring system including GPS, wind and motion sensors. These feed information to the on-board computer that controls the angle and output for each of the thrusters, allowing the ship to maintain a fixed position with regard to either the seabed or a submersible vessel. Such systems are regularly employed for offshore drilling and in situations where anchoring is not possible, because of water depth or congestion on the seabed, due to pipelines for example. While this set-up boasts many advantages including increased manoeuvrability, no limitation on water depth and quick set up time, there is a considerable disadvantage in that the system can fail and blackouts can occur. In such cases there is a very real danger of the ship drifting off course, damaging the pipelines and causing catastrophic leakage, not to mention equipment damage.
To address this problem, SECC has developed a patented technology whereby pressure balanced emergency breakaway connectors provide ship drift/drive off protection for vessels in case of dynamic positioning loss. Positioned subsea and/or topside, the connector will breakaway in a drive off scenario while under full working pressure, providing a dry seal on either side of a valve. This provides essential protection for crew, equipment and the environment as well as significantly reducing operational downtime due to ease of connection and disconnection.
The connectors are manufactured from high grade nickel alloys and super duplex steels due to pressure and chemical resistance requirements. The most important aspect in the operation of the breakaway connector is achieving an effective seal in the connector valve when the connection is broken.
Modern day oil and gas exploration is becoming an increasingly complex process, involving extreme environments that pose significant safety concerns for both workers and equipment. As more traditional and easily accessible sources of raw materials deplete, exploration companies are drilling deeper and in more extreme environments in order to maintain production.
Offshore drilling presents its own specific problems. Equipment is exposed to considerably high pressures while experiencing low temperature environments. This combination can force an elastomer beyond its glass transition temperature, causing the seal to fail and leakage to occur. It is therefore important that any equipment intended for offshore exploration is tested and proven to perform at pressures upwards of 15,000 psi and at temperatures ranging between -18oC to 121oC. Whether drilling onshore or offshore, exploration operations are increasingly encountering aggressive and highly toxic chemicals, in particular hydrogen sulfide, also known in the industry as sour gas. This substance is highly corrosive and can cause extensive damage to equipment and sealing materials, not to mention being extremely hazardous to personnel and the environment. Due to these factors, emerging regulations are increasingly stringent requiring high performance equipment to ensure that safety standards are met and the environment is protected.
SECC’s self-sealing technology has been developed as a risk management and safety measure, which in the case of ship drift will prevent extraction pipelines from rupturing and the marine environment from being polluted. The disconnect valves also prevent contamination of the raw hydrocarbon materials by seawater. The connector is easily operated by a Remotely Operated Underwater Vehicle (ROV), but can also be operated by divers, actuators or winches, allowing operators to dispense with guillotines and other uncontrolled subsea and topside emergency disconnection systems. In order for SECC’s connectors to provide a dry seal on disconnect, high performance sealing materials are required that can form an airtight seal on either side of the connector.
SECC initially approached Precision Polymer Engineering (PPE) to take advantage of the company’s extensive in-depth knowledge of both the oil and gas industry and elastomer sealing solutions for demanding applications. With a need for a high performance low temperature tolerant seal, the two companies worked together to develop a sealing solution that performs to SECC’s highest expectations as well as the specifications set out by the industry’s regulations.
PPE to the rescue
PPE provides high performance sealing solutions tailored to the needs of the customer. SECC contacted PPE with requirements for an alternative seal capable of withstanding high temperatures, high pressures and demanding chemical media. After a review of the process condition.
SECC has integrated PPE’s G75LT and G90LT seals into its breakaway connectors with much success, and since have reported no incidents of seal failure leading to environmental impact. As even a single incident of seal failure has significant cost and environmental implications, it is important that should a DP failure occur, the breakaway connection forms a completely airtight seal first time, every time.
SECC is now working to standardize the seals used across specific product ranges and the implementation of PPE’s high performance elastomers are projected to deliver significant long term cost savings.
SECC Oil & Gas is a global supplier of couplings and connectors to the oil and gas industry, specializing in connection and disconnection solutions across the sector with special emphasis on subsea applications. The company has a reputation for innovative connection solutions that improve operational effectiveness, reduced risk and cost. SECC offer pressure balanced, full bore disconnect and permanent connection systems that guarantee greater connection performance with reduced operating costs, through decreased downtime, protected equipment and infrastructure, together with a pollution free and safer operating environment.