Subsea equipment installation

Abstract

The invention relates to the drilling of subsurface oil and gas wells and the installation of subsurface equipment (). A lifting vesselbrings heavy equipment such as Xmas trees or manifolds and wet parks this equipment () on the seafloor () during good weather when the significant wave height is low. The equipment (), once it is underwater, has much lower weight and may easily be moved into place onto a wellhead () at an appropriate time using lower capacity lifting gear. The timing of this operation is much less sensitive to weather conditions because the equipment does not need to pass through the splash zone (sea surface). This makes for efficient use of expensive drilling rig time, and allows for acceleration of production of first wells on the template as critical heavy lifts could not else be done until rig has left the location. (FIG.).