Systems And Methods For Collecting Hydrocarbons Vented From A Subsea Discharge Site

Abstract

A method for capturing at least a portion of hydrocarbon fluids vented into the surrounding sea from a subsea discharge site comprises (a) mounting a pressure control device to the subsea discharge site. Further, the method comprises (b) flowing the vented hydrocarbon fluids from the subsea discharge site through the pressure control device. Still further, the method comprises (c) positioning a collection system subsea on a lower end of a tubular string. Moreover, the method comprises (d) flowing the vented hydrocarbons fluids from the pressure control device into the collection system and through the tubular siring after (b). The method also comprises (e) minimizing lateral and vertical loads applied to the subsea discharge site by the collection system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims benefit of U.S. provisional patent application Ser. No. 61 / 558,827 filed Nov. 11, 2011, and entitled “Systems and Methods for Collecting Hydrocarbons Vented from a Subsea Discharge Site,” which is hereby incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.BACKGROUND[0003]1. Field of the Invention[0004]The invention relates generally to systems and methods for collecting hydrocarbons vented from a subsea discharge site. More particularly, the invention relates to systems and methods for collecting the bulk hydrocarbon flow from a pre-determined, controlled subsea pressure exhaust vent point.[0005]2. Background of the Technology[0006]In offshore drilling operations, a blowout preventer (BOP) is installed on a wellhead at the sea floor and a lower marine riser package (LMRP) is mounted to the BOP. In addition, a drilling riser extends fro...

AI Technical Summary

Benefits of technology

The patent describes a method to capture hydrocarbon fluids that are vented into the sea from a subsea discharge site. The method involves mounting a pressure control device to the discharge site, controlling the pressure of the fluids as they flow through the device, and then using a collection system and a tubular string to transfer the fluids to the surface. The method also aims to minimize the strain on the discharge site caused by the collection system. The technical effect is the efficient and safe capture of hydrocarbon fluids from subsea sources.

Problems solved by technology

However, if drilling operations cannot be resumed, cement or heavier drilling mud is delivered into the well bore to kill the well.

For example, a subsea blowout may damage the subsea BOP, LMRP, or riser, potentially resulting in the discharge of hydrocarbons into the surrounding sea.

However, due to pressure limitations of the wellbore, ay not be desirable or safe to completely shut-in the well with the capping stack.

As another example, a sudden and potentially prolonged release of hydrocarbon fluids at a subsea discharge site may result from the shut-in of a surface flow containment vessel during a cap and flow response operation.

Accordingly, around the clock surface distribution may not be possible (e.g., at night the location and boundaries of the oil slick at the surface may not be visible).

Depending on the weather and sea conditions, surface turbulence may be less than adequate.

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