Patent Publication Number: US-8967273-B2

Title: System for detecting, containing and removing hydrocarbon leaks in a subsea environment

Description:
This application is a non-provisional application which claims benefit under 35 USC §119(e) of and priority to U.S. Provisional Application Ser. No. 61/780,425 filed 13 Mar., 2013, entitled “A SYSTEM FOR DETECTING, CONTAINING AND REMOVING HYDROCARBON LEAKS IN A SUBSEA ENVIRONMENT,” which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a system for the detection, containment and removal of hydrocarbon leaks in a subsea environment. 
     BACKGROUND OF THE INVENTION 
     In offshore oil exploration, it is often necessary to protect subsea equipment from damage from anchors, fishing nets, ice features or other marine hazards. Equipment protruding from the sea floor in high traffic areas, such as shipping lanes or areas with submarine activity, has an inherent danger of damage to either vessels or the environment due to potential oil spills from damaged equipment. 
     To date, subsea drilling equipment such as blow-out preventers and well completion equipment, such as “Christmas trees,” have been located at the sea floor level, leaving them exposed and susceptible to damage. The problem is particularly acute in Arctic waters where ice packs and icebergs scour the ocean floor with great force. Consequently, excavations on the ocean floor, called glory holes, have been used to enable blow-out preventers, wellheads and associated well completion equipment to be relocated below ice scour regions or to protect the wellhead from damages from anchors, fishing equipment or shipping hazards. However, glory holes can be expensive to dredge where difficult soil conditions are encountered or the water is deep. Furthermore, the protection provided against scouring by ice is imperfect, as the ice pushes a pile of rubble ahead of it as it scours the ocean floor, and little protection against anchors, fishing nets and the like is provided. 
     Caissons have also been utilized in the art in an effort to protect subsea equipment from marine hazards. Caissons are generally made from steel or concrete installed below the scour regions in subsea environments. 
     Unfortunately, even with appropriate protection of subsea equipment leakage of hydrocarbons is still a possibility. 
     Therefore, a need exists for containment, detection and removal of hydrocarbon leaks by creating a closed environment where leaks can be detected, contained, and mitigated to prevent hydrocarbons from reaching the environment. 
     SUMMARY OF THE INVENTION 
     In an embodiment, a system penetrating a sea bed of an Arctic subsea environment, wherein the system detects, contains and removes hydrocarbon leaks within the system, wherein hydrocarbon leaks include oil and gas, includes: (a) a hollow caisson, wherein the caisson includes walls and a floor, wherein the caisson is fabricated from any material capable of withstanding a harsh subsea environment, wherein the caisson is fabricated from steel, concrete or any combination thereof; (b) subsea equipment disposed within the caisson, wherein components of the subsea equipment penetrate the caisson; (c) a removable lid for sealing the caisson, wherein the lid creates a fluid tight seal, wherein the lid includes at least one vent, wherein the lid includes a removal port for accessing hydrocarbon leaks within the system, wherein the lid is fabricated from any material capable of withstanding a harsh subsea environment, wherein the lid is fabricated from steel, concrete or any combination thereof; (d) a primary detection means are connected to an inner surface of the lid, wherein the primary detection means detects the presence of hydrocarbon leaks within the system, wherein the primary detection means is a semiconductor or a capacitor; (e) a secondary detection means are connected to components of the subsea equipment, wherein the secondary detection means detects the presence of hydrocarbon leaks within the system, wherein the secondary detection means is either a semiconductor or a capacitor; and (f) suction means penetrating the lid through removal port, wherein the suction means removes hydrocarbon leaks from the system, wherein the suction means is a flexible suction hose. 
     In another embodiment, a system for detecting, containing and removing hydrocarbon leaks within the system, includes: (a) a hollow caisson penetrating a sea bed of a subsea environment; (b) subsea equipment disposed within the caisson, wherein components of the subsea equipment penetrate the caisson; (c) a removable lid for sealing the caisson, wherein the lid creates a fluid tight seal, wherein the lid includes a removal port for accessing hydrocarbon leaks within the system; (d) a primary detection means are connected to an inner surface of the lid, wherein the detection means detects the presence of hydrocarbon leaks within the system; and (e) suction means penetrating the caisson for removal of leaked hydrocarbons. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a schematic of an embodiment of the present invention. 
         FIG. 2  is a view taken across line  2 - 2  in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not as a limitation of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations that come within the scope of the appended claims and their equivalents. 
     The system in accordance with the present disclosure serves to protect any wellhead equipment housed within the structure from damages; to prevent the infill of the structure with sediment being moved by ocean currents or ice; to contain and detect hydrocarbons that have been released into the system; and to remove hydrocarbon leaks within the system. Referring to  FIG. 1 , there is shown a subsea caisson  10  penetrating the sea bed  8  of a subsea environment  6 .  FIG. 1  depicts a cylindrical caisson  10 , however, the structure can be any shape suitable for the intended purpose. The caisson can be fabricated from any material capable of withstanding harsh marine environments. Harsh marine environments, for example, can include ice packs, iceberg scour and anchors. Such material capable of maintaining structural integrity in harsh subsea environments can include steel, concrete or combinations thereof. 
     The caisson may include a floor. The caisson can be fabricated from any material capable of withstanding harsh marine environments. The floor can be fabricated from steel, concrete or combinations thereof. 
     The caisson  10  contains subsea equipment  12 . Such subsea equipment can include, but is not limited to blow-out preventers and well completion equipment. The subsea equipment can penetrate the caisson. 
     A removable lid  14  forms a roof to seal the caisson  10 . When attached to the caisson  10 , the removable lid  14  creates a fluid tight seal to prevent the entrance of water into the system and to contain any hydrocarbon leaks within the system. The lid can be fabricated from any material capable of withstanding harsh marine environments. Ice packs, iceberg scour, anchors or other marine hazards are examples of harsh marine environments. Such material capable of maintaining structural integrity in harsh subsea environments can include concrete, steel or combinations thereof. 
     The lid  14  includes a removal port  22  capable of providing access to the hydrocarbon leaks contained within the system. When hydrocarbon leaks are detected within system, a plug  18  is removed from the removal port  22  in the lid  14 . The hydrocarbon leak can then be discharged from the system through removal port  22  and into suction means  20 . The suction means  20  allow flow from the system through a flexible riser  24  to the surface. The suction means can be a flexible hose. The suction means can be attached to the lid via a flanged connection. 
     The lid may include at least one vent  26  to vent. The lid may also include lifting eyes  28  for removal of the lid  14  from the caisson  10 . 
     Primary detection means  30  may be located on the interior surface of lid  14 . The primary detection means are capable of detecting the presence of hydrocarbon leaks within the system. The primary detection means can include, but are not limited to semiconductors or capacitors. A hydrocarbon sniffer is an example of a primary detection means. 
     Secondary detection means  32  can be included on the subsea equipment. The secondary detection means are capable of detecting the presence of hydrocarbon leaks within the system. The secondary detection means can include, but are not limited to semiconductors or capacitors. A hydrocarbon sniffer is an example of a secondary detection means. 
     In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as an additional embodiment of the present invention. 
     Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.