Design and Application of A New Type of Riser Quick Installation Wellhead Device

In conventional offshore drilling operations, surface drilling often uses seawater bentonite slurry without environmental damage additives as drilling fluid, drilling fluid and returned cuttings are directly discharged into the sea. But with the increasingly strict environmental protection requirements, it is required that the seawater bentonite slurry and the drilled cuttings should also be fully recovered. However, the conventional surface wellhead devices for offshore drilling are mostly non-closed, and the wellhead device has low production efficiency, high operation risk and poor stability. Based on this, a new type of riser quick installation wellhead device is designed and developed. The device uses slips and BT seals (BT seal is an auxiliary sealing method) to realize the connection and sealing of the riser, which is simple to install and has a good sealing effect. By comparing the installation time of the conventional wellhead device with that of the new wellhead device, the new quick-fitting wellhead is easy to install and reduces the thermal operation time. The installation time of a single wellhead is reduced from 23 h to 2.25 h, and the operation timeliness is increased by nearly 10 times. After the application in Kenli 16-1 oilfield, the operation efficiency is greatly improved and the drilling cost is saved.