Lift/Boarding Vessel

Abstract

In order to board a fixed structure, ocean conditions must be within a reasonable state that allows personnel to board in a safe manner. Due to the specific weather conditions, the boarding of fixed structures cannot be conducted. Both oil and gas and wind platforms must be boarded for maintenance and repair purposes. The invention allows boarding of fixed structures employing three buoyant vessels that can be adjusted to always be heading into the wind direction. Landing piles are pre-driven adjacent to the fixed structure and terminate at the ocean bottom. The invention has three deployable legs that extend through the buoyant vessel to the ocean bottom. The placement of the driven supports employs the same dimensions as the spacing of the vessel's extension legs. The vessel operator adjusts the heading of the three buoyant vessels to the wave heading. The legs are extended to the ocean bottom.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The boarding of fixed structures in offshore waters is the subject of this invention. Offshore platforms of all types and uses must be boarded in harsh weather conditions. The invention teaches a method to board fixed, stable offshore structures in harsh conditions which exceed the standard safety guidelines. Attending vessels are employed in the boarding operations at this time in the oil and gas industry as well as in offshore wind power facilities. The requirement to board is very critical and must be provided or financial losses can be realized. For example, boarding of fixed platforms relating to the oil and gas industry is different in specific areas. The North Sea is very active in the production of oil and gas. The average number of days in which boarding is not possible can reach 75 days per year. In other oil and gas areas having a less harsh environment, 10-50 days per year can be lost with relation to the inability to board the vessel. In all cases, both harsh and less harsh downtime conditions of oil and gas operation are not acceptable. Wind farms are also very sensitive to downtime, due to boarding of the platform. The invention provides a method to reduce the days of downtime.

In a harsh environment, the present percentage of downtime may be as great as 21%. In areas that have a less harsh environment, the percentage may be as great as 3%. The invention can reduce the platform downtime due to boarding problems to 5% in harsh conditions and less than 1% in less harsh conditions. The invention's most permanent advantage is the ability to provide a safe and stable platform for the transfer of workers. The financial rewards of the use of this invention is very great both in the oil and wind industry.

2. Description of the Related Art

U.S. Patent Application Publication No. 61/687,770 discloses a harsh environment lift boat.

The invention disclosed and taught herein is directed towards a major improvement of wind systems to be used onshore or offshore.

BRIEF SUMMARY OF THE INVENTION

The ability to provide a safe and efficient means of boarding offshore platforms is the basis of this invention. Safety at sea is the most important factor in offshore operations. The invention teaches a method, which allows the boarding vessel to be stable and static. Hence, both the platform to be boarded and the boarding vessel are static (no relative motion). This invention is novel because all other ocean boarding vessels have a condition in which one item (platform) is static. The boarding vessel is dynamic.

It is understood by offshore managers, workers and seamen that the only method to provide a safe means of boarding an offshore platform is that both platform and vessel must be in a static condition. The invention teaches the method and procedure.

The underwater pre-driven ocean bottom piles provide a landing area, which allows predictable results and the pre-loading procedures or “punch through” are non-existent. The ocean bottom and structure have different strengths. The support legs of typical lift boats can lose footing due to “punch through”. By use of the invention, “punch thrus” are non-existent. The offshore platforms that require boarding in water depths from 10′ through 300′ can be boarded via this invention.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a profile view of the offshore boarding vessel. The profile illustrates the buoyant vessels, the extension legs and the main vessel body.

FIG. 2 illustrates a view of the main vessel body in an elevated mode showing the air gap between the bottom of the vessel body and the surface of the water.

FIG. 3 illustrates a plan view of the invention. Three buoyant units are shown and connected to the main body via a structural frame. The main vessel body is located between the three buoyant units.

FIG. 4 illustrates the three buoyant units located within a triangle equidistant from each other.

FIG. 5 illustrates a singular buoyant unit. The illustration is a plan view of the unit. The main connection area is illustrated.

FIG. 6 illustrates a profile sectional view of the buoyant unit. Bearings, lifting legs and vessel body are shown.

FIG. 7 illustrates the invention shown in front profile. The main body, buoyant units and structural connection members are shown.

FIG. 8 illustrates the structural connection members to two of the three buoyant units.

FIG. 9 illustrates the invention in an elevated mode. The pre-driven mud line piles are shown. The invention created is seen mounted above the pre-driven piles. The invention is in an elevated mode. The elevation can be adjusted upon command.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 illustrates the invention (1) shown from a profile view.

The vessel has support legs (2) which extend above the vessel to a specific height. The lower extremity of the leg sections is connected to the buoyant units 6a-6b-6c. A control unit (3) is mounted above the vessel allowing for full viewing of the overall operation.

The main body (4) of the vessel contains the prime movers, hydraulic pump, quarters and crew accommodations. Above the buoyant units is a bearing and gear box housing (7). A leg jacking tower (8) is located above the buoyant unit (6c)

A structural bridge (9) connects the buoyant units 6a, 6b and 6c. Each buoyant unit is fitted with a propulsion unit (10). The propulsion unit is controlled from the pilot house (3).

The buoyant units have a specific draft allowing a freeboard above the sea level (11).

FIG. 2 illustrates the main vessel body (4) elevated above the seal level (4). The “air gap” or elevation distance is shown in FIG. 2 or 14. The elevation of the master body is accomplished by the extension legs (2). The buoyant units 6a, 6b and 6c remain in place at sea level (11).

The invention is illustrated in FIG. 3, Item 1. The illustration shows a plan view of the vessel (1). The plan view shows three independent buoyant units 6a, 6b, 6c and joined to the main vessel body (4) by structural members 9 and 12.

The main vessel body supports the pilot house (3) which controls the overall functions of the vessel (1). The main vessel body (4) contains the prime mover (5). The prime mover (5) is a diesel electric system which provides power to the buoyant units (6a, 6b and 6c) and other requirements of the vessel. The pilot house (3) has full command of the motion of the vessel (1), i.e. forward/reverse movement. Port and starboard movement and lifting of the main body above the ocean level.

General operation of the vessel (1) in a transit mode requires that the buoyant units are located bow/stern positions. To guide the vessel (1), the operator located in the pilot house, rotates the buoyant units (6a, 6b, 6c) either to the port or starboard direction. Each buoyant unit (6a, 6b, 6c) can be positioned separately to reach the desired location. The vessel (1) can be positioned to meet the demands of platform boarding and to place the vessel above and onto the driven mudline-located support pilings.

In sea conditions which are not aligned with the platform, the buoyant units can be positioned in such a fashion to maintain heading into the sea action at all times. In harsh seas, the vessel captain located in the pilot house (3) can position the vessel above the driven pile supports (29) as seen in FIG. 9.

The vessel captain will employ side beam sonar to locate the driven piles (29). The captain will “land” one of the three jacking legs onto the driven pile once a load is placed onto the leg created from the partial weight of the vessel. The two other support legs are positioned above the two remaining driven piles. Once the location is correct, the vessel is lifted to provide an air gap (14) between the bottom of the vessel and the ocean surface.

The task of lifting the vessel from the ocean surface is simplified if the buoyant units are positioned heading into the seas, experiencing only a heave action.

This factor is very important to simplify the location and elevation of the vessel out of the sea action.

The ability of the vessel to change the heading of the buoyant unit provides a manner which allows employees to board vessels in a proper boarding manner.

The spacing of the buoyant units is illustrated in FIG. 4. Each unit has its own jet drive (1) which is controlled separately. The spacing of the buoyant units is critical to meet the size and shape of the driven piling (29). The buoyant units (6a, 6b and 6c) are equipped with a special yawing device which is powered and controlled by the vessel captain. See FIG. 5.

The jet drive (10) is driven via an electrical drive (19). The buoyant units (6a, 6b and 6c) are equipped with a radial bearing (7) and gear drive (8). The pod can be rotated about the lifting leg (2). The buoyant units can be rotated 360 degrees with respect to the bow/stern centerline.

FIG. 6 illustrates a sectional drawing of the buoyant unit. FIG. 6 illustrates the general arrangement of the buoyant units. The buoyant units (6a, 6b and 6c) are equipped with a bearing assembly (17, 18, 22, and 23). The bearing assembly supports the buoyant units to move about the jacking assembly (8) and the jacking legs (1). The buoyant units are controlled by a powered yaw system (15). A gear (16) causes the movement of the buoyant units as per central command.

The lower section of the leg is equal with a concave section (20) designed to fit onto the mud-line driven pile. Each of the buoyant units (6a, 6b, 6c) area equipped with the identical equipment. The control of the buoyant unit is a decision in which the vessel captain employs due to the sea action.

On the vessel near the platform, the captain determines the sea heading. The captain adjusts the buoyant units (6a, 6b and 6c) into the sea to avoid any lateral motion of the vessel. Only heave is being experienced by the vessel.

The captain then positions the vessel above the pre-driven support piles to conduct the mounting process.

The vessel is considered to be a tripod unit providing equally-spaced buoyant units. FIG. 7 illustrates a frontal view of the vessel showing two of the three buoyant units (6a and 6b).

The arrangement of the pilot house (3) is illustrated. The lifting system shown: Bearing assembly (7), jacking tower (8) and jacking leg (2) is seen in the arrangement.

The captain has visual contact with all components of the boarding vessel. The prime mover (15) is within the area in which the captain performs the control operation.

FIG. 9 illustrates the structural member which attaches the buoyant units (6a, 6b and 6c). The structural member is of sufficient size to allow human access to all areas of the vessel.

The basic purpose of the vessel allows a stabilized platform to board a fixed offshore platform.

FIG. 9 illustrates the invention in an operational mode. The advantages of this vessel are as follows:

Provide stable platform to perform boarding and general offshore operations without the effect of the sea action.

Provide buoyant units which allow the vessel to experience only a heave motion.

Lifting legs are provided to raise the vessel above the sea action wherein the vessel is mounted onto stable pre-driven piles.

Typical operations require that a lift boat be pre-loaded prior to operation. This procedure allows a test which indicates that the vessel can be operated considering that the structural strength of the soils can withstand the load. The invention avoids this process allowing a greater cost efficiency of the process.

The invention teaches a method of offshore operation which provides a safe and efficient method to board offshore fixed platforms. The ability to board the platform is paramount. The invention can provide the vessel captain a greater ability to operate the lift vessel in harsh seas.

Claims

1. A downhole drilling system for drilling micro-holes in earth formations comprising: a surface control unit which programs the action of the downhole tool and provides high-pressure fluid pressure to the downhole tool which in turn, by robotic action, parts the casing and drills a micro-hole to a general location, which is pre-programmed from the surface for the enhancement of oil and gas production.a. A marine vessel which can provide a method to operate offshore in a harsh weather condition comprising of:b. A vessel which provides a stable work platform without the effect of sea action.c. A vessel which can control the vessel when in the sea action which allows only a heave action to be subjected to the vessel.

2. To provide a method in which the vessel can be placed into operation without costly pre-loading.

3. A vessel of claim 1 which provides buoyant units which all fully operate to adjust the basic principles of the vessel employing the adjustment system which is controlled by the vessel captain.

4. The vessel of claim 1 to provide jacking legs which are mounted through the buoyant units and upon command, the captain can lift the vessel from the sea level.

5. The vessel of claim 1 allows the operation of the vessel when underway to operate as a standard marine vessel with respect to navigation, docking and other standard marine operation procedures.

6. The vessel of claim 1 provides a central prime mover service which provides power to the three buoyant, adjustable units.

7. The invention is a marine vessel which can provide certain qualities which are used in the offshore operations in a harsh sea state allowing the vessel captain to depart a safe harbor traveling to the offshore location, adjusting the buoyant units to remain yawing of the vessel, providing only a heave action, docking the vessel onto pre-driven support units and lifting the vessel without pre-loading to the desired work height above the sea action providing a static platform to perform operations.