Abstract: A riser-based slug control system and a method of controlling slugging in a fluid flowing through a riser are provided. The system includes a gas-liquid separation separator that has a housing defining an internal volume. An inclined inlet is connected to the housing and configured to receive a flow of multiphase fluid and direct the flow of fluid into the housing so that the fluid flows spirally in the volume and separates, with gas from the fluid collecting in an upper portion of the volume and liquid from the fluid collecting in a lower portion of the volume. A tubular passage, which extends at least partially through the internal volume of the housing, defines a plurality of orifices. The tubular passage is configured to receive liquid from the lower portion of the volume and gas from upper portion of the volume, and deliver the mixture of the combined liquid and gas through an outlet.

Abstract: Accurate, dependable methods for analyzing operational parameters of subsea control systems and diagnosis/prediction of failures are provided, in particular, methods for detection of leaking and/or clogging in hydraulic control system using recorded pressure signals and evaluating response communication strength (signal amplitude) of field equipment from, for example, subsea control systems. Prediction of failure(s) allows an opportunity to prepare for intervention to minimize the impact of failure before failure occurs, for example, by ordering equipment, tools and/or scheduling an intervention vessel. Similarly, diagnosing a failure drastically shortens the intervention time.

Abstract: A method and system for performing intervention and workover operations on a subsea well are provided, as well as an adapter for connecting a lower end portion of a conduit extending from a vessel with an upper portion of a lower marine riser package associated with a subsea tree. The method includes providing a lower marine riser package connected to an upper portion of a subsea tree associated with a subsea well, and a conduit extending from a vessel toward the lower marine riser package. The conduit is connected to the lower marine riser package with an adapter. A portion of a conduit bore of the conduit above the adapter is sealed from a chamber in the adapter, and a portion of a bore extending through the lower marine riser package is sealed from the chamber. The adapter is opened for access to the chamber from the sea.

Abstract: A method for installing a subsea flowline and riser assembly on a sea floor includes providing a flowline having an axis and an end connected to a hinge-over joint, and a riser having an axis and an end connected to the joint such that the axes of the riser and flowline extend substantially parallel. An end of the flowline opposite the joint is lowered to the sea floor. The end of the flowline connected to the joint is lowered to the sea floor. The joint is connected to a foundation that is installed in the sea floor. The riser is rotated about the hinge-over joint such that the riser axis is substantially perpendicular to the flowline axis. A subsea jumper is connected between an opening formed in the flowline and an opening formed in the riser so that the riser is in fluid communication with the flowline.