Recently, reports of Lingshui 17-2 gas field development project have been reported frequently! On February 24, the first umbilical cable with a depth of 1500 meters was successfully installed in China. On February 28, the first steel catenary riser (SCR) in China with a water depth of 1500 meters was successfully connected back into place.
Two "nutrient delivery pipes" have been put in place in the deep sea one after another, marking that China has fully mastered the deep-water technologies such as the laying of 1500m deep horizontal pipe, the laying and connection of Steel Catenary Risers, and the construction and installation of subsea pipeline terminal structures, which has accumulated experience for the laying of main umbilical cable with higher technical difficulty and operation risk, and also strengthened the confidence of CNOOC in other large-scale offshore operations.
Lingshui 17-2, a self operated offshore gas field in China, is developed in the mode of "semi submersible production platform + underwater production system". The umbilical cable is the "central nerve" for gas field production. The diameter of the umbilical cable laid this time is 15.9cm and the length is 4.7km. The semi submersible production platform, namely "deep sea No.1" energy station, transmits hydraulic oil, chemical agent and electric power control signals to the underwater production system through various pipelines in the cable, so as to realize the real-time monitoring and remote control of the underwater production system.
In the face of the high difficulty operation of umbilical cable laying, the construction party carried out a detailed comprehensive analysis of technology and risk, carried out simulation drilling and detailed technical disclosure, so as to ensure that every operator has a plan in mind. The operation started on February 20. On the deck, all post personnel cooperated with each other; Underwater, two ROVs operate precisely. Due to the efficient construction of each link, the laying of * * umbilical cables only takes 4 days, and all links are completed in one go.
The SCR installed this time is a chemical pipeline with a diameter of 6 inches and a total length of 4.43 km. It was laid in August last year. On February 28 this year, the construction team grabbed the weather window and completed the riser back connection in only 20 hours.
In the stage of riser tie-in, the project formed a riser upgrading special group to repeatedly demonstrate the upgrading scheme, so as to ensure the construction quality and safety from the source of the scheme. During the tie back operation, the project team put in 2 large ships and arranged 6 underwater cameras. With the help of ROV and divers, the project team worked hard day and night to complete the riser tie-in operation 2 days ahead of schedule.
"Next, there are six more umbilical cables to be installed, of which the main umbilical is longer and heavier, and the installation is more difficult. We are working with the operator to optimize the plan to ensure that all umbilical cables, including the main umbilical, are laid safely and smoothly. " Lingshui 17-2 gas field development project general manager you Xuegang said.
It is understood that after the completion of the first riser tie-back operation, the builders of "deep sea No.1" will work hard to complete the tie-in of the remaining five risers and system commissioning as planned, laying the foundation for the platform to be put into operation on schedule（ CNOOC)