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1. Field of the Invention. The invention disclosed and taught herein relates to the drilling of oil and gas wells located in shallow water such as rivers, bays and sounds and also has the stability to be transported and operated in an ocean environment to a depth of 60′-0″ to 100′-0″.
2. Description of the Related Art.
U.S. Provisional Patent Application No. 61/742,300 filed on Aug. 7, 2012 discloses a drilling vessel with special specifications, which allows the drilling barge to enter narrow/shallow areas to perform service work. The drilling vessel is resting on bottom during drilling operations. By adjusting the vessel stabilizers, the drilling barge performs drilling services in deep offshore waters and can be towed in the open ocean conditions.
U.S. Pat. No. 6,203,247 discloses the detail of methods employed in the drilling barge station-keeping anchors and powered spuds.
The invention disclosed and taught herein allows one drilling vessel to service several work areas such as water depths, ocean conditions and other environmental conditions.
The variable stable drilling barge has been invented to allow one vessel to service several areas. Drilling barges are “stand alone” units used to perform drilling operations in marine environments such as rivers, bays and sounds. These barges are known as “swamp barges”. The drilling barge is operated with the hull ballasted down so that the hull rests on bottom. The average operating water depth is 8′-0″ to 18′-0″ in the inland marine areas. Throughout the world near-shore oil and gas properties are present. At this time, expensive jack-up type rigs are employed.
The invention allows one drilling vessel to enter the inland waters which are shallow (8′-0″ to 20′-0″) and the entrances are narrow and by employing adjustable stabilizers allows the same vessel to enter the shallow offshore waters to operating depths of 60′-0″ to 100′-0″
The vessel has many other qualities to allow the vessel to operate in the vast service area. In order to lower the center of gravity of the vessel, heavy drilling and well service equipment is placed in the lower hull. The relocation of the engines, pumps and support equipment allows the vessel to be stable during service work being conducted in the rivers, bays and sounds. In operations in the rivers, bays and sounds, the stabilizers are in a stowed mode.
The deployment of the stabilizer tanks is conducted employing the river tugs. The stabilizer tanks are saved inboard. The locking pins are removed allowing the stabilizers to be moved outward using the tugboats. Once the tanks are in the deployed mode, they are locked in place via pins.
The invention operates in a near-shore mode. Ocean action is present in the form of breaking waves and ground swells. The drilling operation calls for the vessel to remain on location at all times. The invention has two methods to maintain station while drilling operations are conducted.
Each stabilizing tank is equipped with powered spuds, which are operated from the main vessel unit. Hydraulic motors and a gear rack design allow the spuds to be deployed or retracted by command. The powered spuds are designed to provide penetration from 5′-0″ to 30′-0″.
In support of the powered spuds, a four-point anchoring system is employed. Two anchors are set, port and starboard. Two additional anchors are set directly ahead of the vessel bow. The anchor winches are located at the lower hull, from which the cables are directed upward to the upper hull. The cables are then redirected to the deck level. The cables are connected to suitable anchors. The anchors are deployed via the support tugs.
The mooring of the vessel is provided by both a powered spud and an anchoring system. The bow anchors are set a suitable distance from the drilling barge. In case of a well blowout, the vessel can be winched from the well center via the bow anchor/anchor winch system. The vessel's captain can command that the vessel be de-ballasted and the winches engaged. As the vessel is de-ballasted, the winches retract the vessel from the well center allowing the well to be accessed by firefighting crews.
The upper structure of the vessel is constructed of lightweight composite materials. All non-loaded structural members will be constructed of composite materials and fastened to the steel support members. The weight reduction is sustained and again allows a lower center of gravity for the unit.
The composite materials have an excellent resistance to weathering, rusting or chalking. Hence, an extended useful life is possible with a low maintenance cost.
The living accommodations are also constructed of molded composite materials. The internal structures of the quarters are also constructed of composites including doors, galleys, tables, benches, etc. This design method will also lower the weight located on the upper deck.
The heliport is located at an extreme height. The weight of the heliport is reduced by use of an aluminum construction and trapezoidal structure design. Marine-grade materials will be employed. The heliport extends outward from the bow and is supported via plate girders. The box girders also serve as intake ducting for the vessel's ventilation system.
Drilling of gas wells is different from oil wells. During a gas well blowout, gas can surround the rig with explosive gas. The drilling rig's ventilation system can be subjected to surrounding gas. The invention has a special ventilation system, which allows the ventilated air to be taken from the farthest point from the well center allowing the safest method for providing ventilated air.
Once the invention is placed on bottom and is moored by powered spuds and anchors, movement of the barges should not be conducted in drilling of serviced wells. The drilling mast and substructure are mounted onto a rail system. This system allows the drilling of clustered wells without moving the drilling vessel.
The mast that is employed with the invention provides a height that allows four joints of pipe to be drilled in one event (quad). This system allows a more efficient drilling program. The mast is supported by an automatic drill pipe handling system. The drilling operations are conducted without the use of human effort. All systems are robotic.
Due to the design of the vessel, boarding of the vessel is only conducted by use of the personnel lift system. Non-authorized persons cannot board the vessel, which assures a safe working area for the employees and owners.
The invention provides many systems and devices that enable the vessel to be very economical with relation to the extended service area provided.
The upper deck 16 is supported by the vessel's vertical extension structure 17. The movable substructure 11 is illustrated where several wells can be drilled without moving the vessel. An extended mast unit 12 is approximately 45′ greater in length than standard masts.
A typical anchor unit is employed in the anchor mooring system 15. The anchor units are fitted on the bow (port and starboard sides) and on the stern (port and starboard sides) of the vessel.
The invention as illustrated in
This system allows the vessel's service area to be increased exponentially. The drilling barge has the stabilizers stored (
In remote areas, inland areas are reached via dredging which is very expensive. Hence, this invention has been designed to operate in water depths of 8′-0″. Most standard drilling barges have a minimum water depth of 9′-6″ to 10′-0″. The vessel has been designed to be equipped with rounded ends (bow and stern) which allow travel in narrow passages. The invention can enter any and all locations which can be reached via standard drilling barges.
The vessel captain can adjust the drilling barge for offshore towing and near-shore operations. The captain will deploy the four stabilizer tanks and lock the units in place. The deployment project is conducted in sheltered waters. Once the stabilizers are deployed, a trimming process is conducted for towing purposed. The offshore tug is engaged and the vessel can be towed in coastal areas. The continental shelves of the world have vast expansion of shallow water extending many miles from the shoreline. Hence, water depths between 60′-0″ and 100′-0″ can be located over 20 miles from the shoreline.
Once the vessel is “on location”, the vessel is ballasted down whereas the lower hull rest on sea bottom. The hydraulic powered spuds are engaged and locked in place. The offshore tug will deploy an array of anchors. The anchors are set into place. The invention is prepared for drilling operations. Between 2 and 12 wells can be drilled from one location without moving the vessel.
In general, the rig has the ability to secure inland marine areas and shallow water, near shore ocean waters.
The application is a non-provisional, and claims priority benefit, of U.S. Provisional Patent Application No. 61/742,300 filed on Aug. 7, 2012 which is incorporated herein by specific reference.
Number | Date | Country | |
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61742300 | Aug 2012 | US |