Modular, Distributed, ROV Retrievable Subsea Control System, Associated Deepwater Subsea Blowout Preventer Stack Configuration, and Methods of Use

Abstract

A distributed function control module adapted for use in a modular blowout preventer (BOP) stack for use subsea comprises a housing adapted to be manipulated by a remotely operated vehicle (ROV) with a stab portion adapted to be received into a BOP stack control module receiver. Control electronics, adapted to control a predetermined function with respect to the BOP stack, are disposed within the housing and connected to one or more controllable devices by a wet mateable connector interface. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope of meaning of the claims.

Description

RELATION TO OTHER APPLICATIONS[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 12 / 729,929 filed on Mar. 23, 2010 which was a continuation of U.S. patent application Ser. No. 11 / 205,893, filed on Aug. 17, 2005 now U.S. Pat. No. 7,216,714, issued May 15, 2007 which claims the benefit of U.S. Provisional Application No. 60 / 603,190, filed on Aug. 20, 2004.FIELD OF THE INVENTION[0002]The inventions relate to offshore drilling operations and more specifically, to a deepwater subsea blowout preventer stack configuration and its control system architecture, system interface, and operational parameters.BACKGROUND OF THE INVENTION[0003]When drilling in deepwater from a floating drilling vessel, a blowout preventer stack (BOP Stack) is typically connected to a wellhead, at the sea floor, and a diverter system, which is mounted under the rig sub-structure at the surface via a marine riser system. Although pressure containing components, connectors, structural...

AI Technical Summary

Benefits of technology

The patent text discusses a deepwater subsea blowout preventer (BOP) stack and its control system architecture. The technical effects of the patent include improving the overall system architecture and control system reliability, particularly in the control system components and interface, by addressing the additional operational requirements and complexities of deepwater development commitments. The patent also proposes a solution for retrieving any portion of the BOP Stack in case of failure, which is time-consuming and costly.

Problems solved by technology

Recent deepwater development commitments have placed increased demands for well control systems, requiring dramatic increases in the functional capability of subsea BOP Stacks and, in turn, the control system operating methodologies and complexity.

These additional operational requirements and complexities have had a serious effect on system reliability, particularly in the control system components and interface.

Although redundancy provisions are provided by the use of two control pods, a single point failure in either control pod or function interface is considered system failure necessitating securing the well and retrieving the lower marine riser package, containing the control pods, or the complete BOP Stack for repair.

Retrieving any portion of the BOP Stack is time consuming creating “lost revenue” and rig “down time” considering the complete marine riser must be pulled and laid down.

Running and retrieving a subsea BOP Stack in deepwater is a significant event with potential for catastrophic failure and injury risk for personnel involved in the operation.

Substantial increases in the overall weight and size of high pressure BOP Stacks has created problems for drilling contractors who have a high percentage of existing vessels, which will not accommodate these larger stacks without substantial modifications and considerable expense.

In most cases, the larger, heavier and more complex units are requiring by operators for “deep water” applications and reduce the potential for negotiating a contract for the particular rig without this equipment.

Images