ROV-based subsea well intervention cap

A subsea well intervention cap is provided. The subsea well intervention cap includes a frame, a first clamp segment coupled to the frame and configured to be fitted over a horizontally oriented flowpath of a subsea well equipment component, and a second clamp segment having a rim segment configured to interface with the first clamp segment, wherein the second clamp segment is movable with respect to the first clamp segment. The subsea well intervention cap also includes an actuation mechanism coupled to the frame that actuates the second clamp segment in a vertically upward direction and in an axial direction with respect to the frame toward the first clamp segment. The subsea well intervention cap is lightweight and able to be installed on subsea well equipment using a standard remote operated vehicle (ROV).