TECHNICAL FIELD

The aspects and embodiments thereof relate to the field of support structures for well cellars.

BACKGROUND

When an oil or gas well is on its end of life, the well is abandoned. To prevent oil or gas from leaking out of the abandoned well, a plug may be used to seal the well. This plug may for example comprise cement. Part of the well may be positioned near or at the surface. To reuse the ground surrounding the well at this surface, it may be preferred to remove a top of the well and to bury the remained of the abandoned well underground in a safe manner.

WO2022 164322 discloses a device and method of placing a seal plug in a liner of a well. The device is suspended from a crane and lowered into the well.

SUMMARY

Although the device and method disclosed in WO2022164322 already allow for convenient and safe well abandonment, it remains an object to improve on methods for well abandonment. In particular, it is an object to provide for a more safe, fast, convenient, and/or efficient method of accessing the well and/or performing one or more operations on the well. Such operations in particular relate to operation required for safe abandonment of the well, such as but not limited to placing a seal plug.

To this end, a first aspect provides a method of positioning a working surface over an underground structure, such as but not limited to a well, which underground structure is positioned in a well cellar, ditch, or hole. The method comprises steps of providing a support structure comprising a working surface for supporting one or more pieces of equipment and/or personnel, and positioning the support structure such that the working surface is positioned above the underground structure.

When the working surface is positioned above the underground structure, equipment and/or personnel may access the underground structure in a more convenient and/or safe manner for example compared to conventional methods using a crane.

In the present disclosure, mainly a well is mentioned as an example of an underground structure. However, it will be understood that wherever well is mentioned, examples are envisioned wherein the well is substituted with any other underground structure. Any of the technical effects and advantages of features disclosed herein in conjunction with a well also apply to other underground structures. Furthermore, any of the technical effects and advantages of features disclosed herein in conjunction with a well cellar also apply to any other hole or ditch.

To for example increase ease of access to the well for equipment and/or personnel on the working surface, the method may further comprise a step of positioning an opening in the working surface above an access opening into the well. As such, equipment and/or material may be lowered through the opening in the working surface into the well, in particular in a generally vertical direction. The opening may have any shape. The opening may be fully enclosed by the working surface, or optionally the opening may be formed by a notch or slit at an outer perimeter of the working surface. The working surface may hence even be generally U-shaped. An opening or notch of the U- shaped working shape may in use be positioned above at least part of the underground structure.

In general, situations are envisioned wherein part of the underground structure may protrude upward out of the well cellar, ditch, or hole - i.e. part of the underground structure may extend above ground level. For example, part of a well head or Christmas tree may extend upward from a well as an example of an underground structure. The notch into the working surface may be used to position the working surface around the part of the underground structure protruding upward out of the well cellar, ditch, or hole. Preferably, the notch is in use oriented generally parallel to a direction in which the support structure is moved during positioning of the support structure.

After positioning the support structure, the support structure preferably spans over two opposing edges of the well cellar. As such, the support structure may be solidly supported by ground or any other surface surrounding the well cellar.

In general, the support structure may comprise a closed and/or open frame which support the working surface. As such, the support structure may comprise any combination of beams, struts, plates, panels, and/or any other structural element.

Preferably, but not necessarily, any embodiment of the method may comprise a step of expanding the working surface after positioning the support structure. In general, a larger working surface may be preferred because it allows positioning of more and/or larger equipment and/or provides more freedom of movement for personnel. A larger working surface may also allow for essentially the entire well cellar to be covered with working surface. However, it may also be preferred to minimize the footprint of the support structure, for example during transportation, handling, and/or storage thereof. A support structure of which the working surface can be enlarged, for example by expanding the working surface, may hence be advantageous.

As a particular option, the working surface is expanded by folding out one or more additional working surfaces comprised by the support structure. The one or more additional working surfaces may together with the working surface form the total available working surface.

Preferably, after expanding the working surface, essentially the entire well cellar is covered by the support structure. In other embodiments, the working surface already covers essentially the entire well cellar without requiring the working surface to be expanded. In other examples, expanding the working surface is not required for essentially the entire well cellar, ditch, or hole to be covered.

In particular when the working surface is used during a process of well abandonment, the method may comprise a step of removing the support structure, wherein the support structure is arranged to provide a temporary working surface. The support structure may generally be reused for another well.

For positioning the support structure, the method may comprise a step of lifting the support structure at one side such that the support structure is temporarily supported by one or more rollers and/or wheels. When the support structure is supported by the one or more rollers and/or wheels, the support structure may be conveniently moved around and positioned relative to the well cellar.

While the support structure is supported by the one or more rollers and/or wheels, the support structure may be moved in a direction generally perpendicular to an axis of rotation of said one or more rollers and/or wheels, and/or the support structure may be pivoted about a generally vertical axis. Said vertical axis may be located at or near the one or more rollers and/or wheels.

A second aspect provides a support structure for use in a method of positioning a working surface over a well, which well is positioned in a well cellar. The support structure comprises a working surface for supporting one or more pieces of equipment and/or personnel.

As a particular option, the support structure comprises an opening in the working surface. Preferably, but not necessarily, the opening is positioned on or near a center line of the working surface, or even at or near the center of the working surface. The working surface of any support structure disclosed herein may be expandable with one or more additional working surfaces. One of the one or more additional working surface is provided by a panel, which panel is moveably connected to the support structure. Preferably, the panel is hingeably connected to the support structure.

It will be understood that the support structure and method disclosed herein may be used in a process of well abandonment. However, any support structure and any method disclosed herein may also be used for other purposes in conjunction with a well cellar.

A non-limitative list of examples of activities which may be performed at least partially using equipment and/or personnel positioned on the working surface may be summarized as: positioning a reel or spool with tubing through which fluid may be put into the well or removed from the well on the working surface; using a winch positioned on the working surface, lowering and/or lifting material and/or objects from the well; lowering and/or lifting pipes, liners, and/or casing from the well using a lowering/lifting mechanism positioned on the working surface; positioning a reel or spool with cables/wiring to be lowered into the well and/or lifted up from the well. The cables/wiring may be used for transporting electrical energy and/or data signals.

When the working surfaces comprises an opening, any of the equipment, material, or parts thereof may be lowered into the well or pipeline through the opening or lifted from the well through the opening. Examples of material are fluids such as mud, cement, sealant, cables, such steel cable to lower or lift material and/or equipment, electric cable for transportation of electricity and/or data signals.

A third aspect provides a method for removing part of a liner of a well or pipe. The method comprises steps of positioning a working surface over the liner using a method according to the first aspect, and lowering a device for severing the liner into the well or pipe, wherein the device for severing the hner is lowered into the well or pipe from the working surface, for example using a loweringdifting mechanism, coiled tubing , piping slickline, winch or crane positioned on the working surface.

Particular advantageous methods for removing part of a hner or a well or pipe are disclosed in WO2022164322, along with a device for removing part of a liner or casing of a well or pile. It will however be understood that generally any other device for removing part of a liner of casing of a well or pile may be used as well.

In general, for any support structure disclosed herein, the support structure may comprise any number of legs for supporting the working surface at a distance from the ground on which the legs are positioned. Conceivably a support structure may be positioned on top of another support structure, for example on a working surface of the another support structure. The top support structure and lower support structure may be any support structure as disclosed herein, explicitly or as a combination of any of the features disclosed herein.

When the support structure comprises one or more legs, which may be legs of any height, one or more or all legs may be supported by one or more wheels or rollers. The one or more wheels and/or rollers may allow the support structure to be wheeled or rolled, for example from one well cellar, hole, or ditch to another well cellar, hole, or ditch. The support structure may comprise one or more engines and/or motors for self-propulsion, or may be towed, pushed, or otherwise wheeled or rolled by another vehicle. Any wheel or roller may be arranged to be rotated about a generally vertical axis.

In general, for any support structure disclosed herein, multiple support structures may be arranged to be positioned alongside each other, for example to obtain a larger working surface. Adjacent support structures may be connected to each other. In general, for any support structure disclosed herein, the support structure may comprise any number of wheels or rollers on which the support structure may be supported in particular while positioning the support structure. External rollers or wheels, for example comprised by a vehicle for transporting the support structure may additionally or alternatively be used, for example for moving the support structure off the vehicle.

A fourth aspect provides a method for placing a seal plug in a liner of a well. A particular advantageous device for placing a seal plug and methods of placing the seal plug are disclosed in WO2022164322. The method according to the fourth aspect comprises steps of positioning a working surface over the well cellar, ditch, or hole using a method according to the first aspect, and lowering a device for placing a seal plug into the liner of the well. The device for placing the seal plug may be conveniently lowered into the liner from the working surface, for example using a slickline, winch or crane positioned on the working surface.

A fifth aspect provides methods for lowering equipment and/or material into a well cellar, ditch, or hole, wherein an underground structure is positioned in the well cellar, ditch, or hole. The methods according to the fifth aspect comprise a step of positioning a working surface over the well cellar, ditch, or hole using a method according to first aspect.

For example, a method according to the fifth aspect may comprise a step of lowering a slickline, braided line or E-line into the well cellar, ditch or hole from a slickline spool placed on the working surface. Equipment and/or material may be suspended from the slickline which is lowered into the well cellar, ditch or hole.

In another example, a method according to the fifth aspect allows a snubbing unit to be positioned above the underground structure from the working surface. Instead of or next to the snubbing unit, according to the fifth aspect, a pipe handling unit may be conveniently positioned above the well cellar, ditch, or hole. In general, equipment may be placed on the working surface before the working surface is positioned above the well cellar, ditch, or hole. Alternatively, the equipment may be placed on the working surface after the working surface is positioned above the well cellar, ditch, or hole.

For any method and any support structure disclosed herein, the support structure may be suspended from a crane and positioned above the well cellar, ditch or hole using said crane.

As it will be understood that equipment may be placed on the working surface before the working surface is positioned above the well cellar, ditch, or hole, support structures are envisioned with any of an E-line unit , snubbing unit, slickline spool, winch, crane, coiled or non-coiled tube or hose for transportation of fluid, pump for transportation of fluid through a tube or hose, a mast with clams to handle tubing to be lowered from or lifted out of the well cellar, ditch, or hole, a rotary table with clamps to rotate a bar, pipe, or any other piece of equipment or material positioned in the well cellar, ditch or hole any other equipment, or any combination thereof connected to the support structure. In general, equipment may refer to any equipment used in the field of maintenance, abandonment, or forming of oil and gas wells.

Methods are envisioned wherein any support structure disclosed herein is positioned above any underground structure in any well cellar, ditch, or hole as disclosed herein, in any combination thereof.

In general, in any method, the support structure may be positioned using a hooklift, cable lift or chain lift system. As such, in general, any support structure disclosed herein may be arranged to eb positioned using a hooklift, cable lift or chain lift system.

Furthermore in general, as an option applicable to any support structure disclosed herein, the support structure may comprising a lowering and/or lifting device for lowering and/or lifting equipment and/or material from and/or onto the working surface. A lowering and/or lifting device may be or comprise at least one of the following, in any combination:

• a crane

• a winch

• a handling mast

• coiled tubing

• slickline

• E-line

• a rotary table

• a hydraulic activator

• braided line

• a pipe handling mast

• drill pipe or tubing grippers

In any method disclosed herein, the method may comprise one or more steps of lowering equipment and/or material into the well cellar, ditch, hole, well, or pipe using a lowering device placed on or connected to the working surface, and/or or one or more steps of lifting equipment and/or material from a well cellar, ditch, hole, well, or pipe, .using a lifting device.

BRIEF DESCRIPTION OF THE FIGURES

In the figures,

Fig. 1A and IB schematically show an example of a well abandonment site;

Figs. 2A-2C show a schematic section view of the well abandonment site;

Figs. 3A-3C schematically show different steps of positioning a support structure;

Figs. 4A and 4B schematically show section views of another example of a well abandonment site; Figs. 5A and 5B schematically depict the well abandonment site respectively of Figs. 4A and 4B in a top view;

Figs. 6A-6B show an example of a dig site; and

Figs. 7A-7B show an example of a structure surrounded by soft surface.

DETAILED DESCRIPTION OF THE FIGURES

Throughout most of the figures, as an example, a well is depicted positioned in a well cellar. It will however be appreciated that instead of a well, any other underground structure such as a pipeline for transportation of oil or gas and/or geothermal energy, CO2 for example for CO2 storage, salt production well, water well, and/or any other pipeline for example for running one or more cables or wiring through may be substituted for the well. Also, instead of a well cellar, any underground structure may be positioned in a ditch or hole. In general, a hole may be defined as any dug hole, cave, pit, or well formed by removing material from the ground, rock formation, mud, or any other substance.

Fig. 1A and IB schematically show an example of a well abandonment site 100, respectively in a section view and a top view. A well 102, for example a production well, is positioned underground, i.e. beneath the surface 104 of the earth were oil or gas may be or have been present. The well 102 is positioned in a well cellar 106 which for example may be formed by vertical walls 108. Generally, the vertical walls 108 are used to contain fluids which may for example leak from the well 102.

The cellar 106 may have a generally rectangular footprint, as for example shown Fig. IB, although other shapes of cellars are envisioned as well. Generally, the well cellar 106 is defined by a number of edges. For example, in case of the rectangular cellar 106, the cellar 106 is defined by a first edge 111 and an opposing parallel third edge 113, and by a second edge 12 and an opposing parallel fourth edge 114. When the well cellar 106 is rectangular in a top plan view, the second and fourth edges may be shorter than the first and third edges. In general, a support structure may be positioned parallel to the short edges, parallel to the long edges, or at any angle relative to any of the edges defining the well cellar 106. When instead of a cellar 106, the method is applied to any other type of hole, the footprint of said hole may have any shape with any number of edges, especially in case the hole is dug for example using an excavator or other construction equipment.

As for example visible in Fig. 1A, the well cellar 106 generally poses a hazardous environment as personnel and/or equipment may fall into the well cellar 106. As such, many safety precautions are required when working around an open well cellar 106, which precautions generally decrease the amount of work personnel can perform in a certain time period. However, as the safety of the personnel is of utmost importance, all required precautions have to be taken.

The well 102 generally comprises one or more casings 117 and liners 110. The well 102 is accessible through an access opening 114, and in general it is an aim to enable one or more tools, devices, materials such as cement, to be lowered through the access opening 114 into the well 102. In order to lower the one or more tools, devices, and/or materials into the well 102, previously, a crane was used. According to the present disclosure, as explained inter alia in conjunction with Figs. 2A-5B, an alternative to using a crane is provided.

Figs. 2A-2C show a schematic section view of the well abandonment site 100, showing the well cellar 106 and part of the well 102. It will be appreciated that for any well abandonment site 100 disclosed herein, the well 102 preferably does not protrude out of the well cellar 106. However, situations wherein the well 102, or any other part of the underground structure does protrude above ground level are envisioned as well. Preferably, in such cases, the working surface has a notch through which the part above ground level can extend in use of the working surface, and preferably also while positioning the support structure 200.

Fig. 2A shows a support structure 200 positioned over the well cellar 106 in which the well 102 is positioned. The support structure 200 comprises a working surface 202 arranged for supporting one or more pieces of equipment and/or personnel. Fig. 2B depicts a piece of equipment 204 supported on the working surface 202. It will hence be understood that the support structure 200 now allows equipment and/or personnel to be positioned over the well cellar 106.

The equipment 204 may generally be used in a method of forming a cement plug in the well 102, which may be required after abandoning the well 102 - i.e. after stopping production from the well. Other examples of equipment are a pipe handling unit, a snubbing unit, a winch, a slickline unit, a coiled tubing unit, an E-line unit, an abrasive cutting unit or any other type of equipment used in conjunction with wells and/or pipes.

For positioning the support structure 200 over the well cellar 106, as an option, the support structure 200 may comprise one or more rollers 208 and/or wheels. As shown in Fig. 2C, the support structure 200 may be tilted such that the support structure 200 is supported by the one or more rollers 208 and/or wheels. The tilting may be caused by the support structure 200 being lifted at one side - in particular an opposite side of the one or more rollers - for example by a crane 300. The crane 300 may for example be provided with a hooklift, and the support structure may be formed as a hooklift container or at least the support structure may comprise a connection member for connecting a hooklift to. Using the crane 300 to position the support structure 200 may be a safe way of positioning the support structure, as it may prevent personnel from being present near the well cellar, which would otherwise present a risk of falling into the well cellar.

To further reduce a risk of falling, any support structure disclosed herein may comprise one or more upright safety barriers such as walls or fences, surrounding at least part of the working surface. In general, an upright safety barrier is sized and oriented to prevent personnel from falling off the working surface into a well cellar, ditch or hole, in particular when the working surface does not cover the entire well cellar, ditch or hole.

Figs. 3A-3C show a well abandonment site 100, and depict different steps of positioning a support structure 200 over a well cellar 106. The support structure 200 is in Fig. 3A carried by a vehicle 300, which vehicle may be a truck, flatbed truck, a vehicle comprising a trailer on which the support structure 200 can be carried, or any other type of vehicle. Preferably, the vehicle 300 has a motor and/or engine for propulsion, and a set of wheels. As such, the vehicle 300 can be used for transporting the support structure 200 to the well abandonment site 100.

In a first step, depicted in Fig. 3A, the vehicle 300 is positioned at or near a first edge 111 of the well cellar 106, in particular with a rear of the vehicle facing towards the well cellar 106. The support structure 200 is moved in a generally horizontal direction towards an opposite edge 113 opposite to the first edge 111. To allow this movement between the support structure 200 and the vehicle 300, the support structure 200 may for example be supported on one or more rollers 304 and/or one or more other friction reducing device reducing friction between the vehicle 300 and the support structure 200 such as a sled. As depicted in Fig. 3 A, during a part of the positioning of the support structure 200, the support structure 200 can be at least in part suspended above the well cellar 106.

After the support structure 200 has been moved further towards the opposite edge 113, the support structure 200 may pivot about a pivoting point 306. The pivoting point 306 is generally comprised by the vehicle 300. As an option, to control the pivoting of the support structure 200, a downward oriented load may applied to a proximal side 235 of the support structure - i.e. a side left of the pivoting point 306 in Fig. 3B. The load may for example be provided by the support structure 200 itself, for example by positioning the center of gravity towards one side of the support structure, a weight of the vehicle 300, and transferred via an arm, such a hooklift hoist, or crane 302 comprised by the vehicle 300.

As such, it will be understood that as an option applicable for any embodiment of the support structure disclosed herein, a center of gravity of the support structure may be positioned at a distance from the center of the support structure. For example, the center of gravity may be positioned in a range between 0% and 45% of the width of the support structure, preferably within a range between 0% and 30% or even between 1% and 20% of the width of the support structure. In general, the width may correspond to a direction in which in use the support structure is moved off the vehicle 300. A first range of 0%-50% of the width is indicated in Fig. 3C as rl, and a second ranged of 0%-25% of the width is indicated in Fig. 3C as r2.

As depicted in Fig. 3B, when the support structure 200 is sufficiently pivoted, the support structure 200 becomes supported on the ground 104 adjacent to the opposite edge 113. At this moment, the support structure 200 can be released to the ground 104 also at or near the first edge 111, for example using a crane or arm 302 of the vehicle, as depicted in Fig. 3C. It may be required to move the vehicle 300 in a direction away from the well cellar 106 to allow the support structure 200 to contact the ground 104 adjacent to the first edge 111. In general, the first edge 111 may be any edge of the well cellar 106, for example any short or long edge, in particular in case of a rectangular well cellar 106.

The positioning method disclosed in conjunction with Fig. 3A-3C generally provides a safe and/or convenient way of positioning the support structure 200. It will be understood that for removing the support structure 200, the steps may be followed in opposite order and/or opposite direction, to position the support structure 200 back onto the vehicle 300. It will thus be understood that the support structure 200 may be formed as a roll off container. Figs. 4A and 4B schematically show section views of another example of a well abandonment site 100 with the well 102 positioned in the well cellar 106. Figs. 5A and 5B schematically depict the well abandonment site 100 respectively of Figs. 4A and 4B in a top view. In conjunction with Figs. 4A-5B a particular optional but preferred feature of the present disclosure will be elaborated on.

In Figs. 4A and 5A, the support structure 200 is positioned such that the working surface 202 is positioned above the well cellar 106. However, in the situation of Figs. 4A and 5A, not the entire well cellar 106 is covered by the working surface 202, for example to prevent the support structure 200 from becoming too large and/or heavy, and therefore hard to move, transport, store, and/or position.

However, it may in examples be preferred to cover essentially the entire well cellar 106, for example for reasons of safety and/or to optimize the available working surface area. Covering essentially the entire well cellar 106 does allow for one or more openings 212 to present in the working surface, as will be elaborated on below.

To increase the useful surface area of the working surface 202, the support structure 200 may comprise one or more additional working surfaces, for example the two additional working surfaces 202’, 202” shown e.g. in Figs. 4B and 5B. In the example shown in Figs. 4A-5B, the additional working surfaces 202’ 202” are provided respectively by hinging panels 214’, 214”. In Figs. 4A and 5A, the hinging panels 214’ 214” are positioned in a generally upright position, at an angle relative to the working surface 202, which angle preferably is between 80-110 degrees, or even perpendicular.

In Figs. 4B and 5B, the hinging panels 214’ 214” are folded down such that the additional working surfaces 202’ 202” are positioned generally parallel to the working surface 202. As such, the additional working surface 202’, 202” can now be used to support one or more pieces of equipment and/or personnel, or may at least prevent or reduce a risk of personnel and/or objects and/or material accidentally falling in the well cellar 106. It will thus be appreciated that the additional working surfaces may be less strong that the primary working surface 202. For example, an additional working surface may be formed from wire mesh and/or may be formed alike a fence, or any other open structure, for example to reduce weight while still allowing the additional working surface to catch personnel and/or equipment accidentally falling onto the additional working surface. As such, the additional working surface can still prevent the personnel and/or equipment from falling into the well cellar, ditch or hole.

It will be appreciated that one or more additional working surfaces 202’ may be provided by other elements than hinging panels. For example, one or more panels may be slidable or otherwise moveable relative to the working surface 202, or generally connectable to the support structure 200.

Another option shown in Figs. 4A-5B, which option may be readily applied to any other embodiment of the support structure and methods as disclosed herein, an opening 212 is provided in the working surface 202. As a further option, even multiple openings 212 may be provided. Although in the figures a circular opening 212 is depicted, in general any opening may have any shape.

In use, the opening 212 may be generally positioned above the well 102, in particular above the access opening 114 into the well 102. This may allow equipment and/or material to be lowered down and/or lifted up generally vertically through the opening 212 into the well 102 through the access opening 114. It will be understood that generally vertically also allows equipment and/or material to be lowered down at an angle relative to the gravity vector, for example in case of a pipeline or well which is positioned at an angle relative to the gravity vector.

It is again stipulated that although in the figures a well abandonment site is depicted, any of the methods and support structures disclosed herein may also be applied to other sites in which a well cellar is present. Furthermore, instead of a well as depicted in the figures, the present disclosure is equally applicable to any other underground structure, such as but not limited to underground tubes or pipes, or cables. Additionally, in any possible combination, the well cellar may be substituted in the present disclosure for any other hole in the ground, any other hole in soil, which may have been paved or unpaved, such as but not limited to a ditch or dug hole.

Fig. 6 A shows an example of a dig site 600 in which a hole 606 has been dug. In the hole 606, part of a pipe 606 is exposed. The pipe 606 is an example of an underground structure. A particular example of a support structure 200 is positioned over the hole 606, with a working surface 204 of the support structure 200 positioned over the pipe 606. As an option generally applicable for any support structure 200, the support structure 200 comprises a notch 216 positioned above the pipe 606. As such, equipment and/or material can be lowered towards the pipe 606 through the notch 216. The working surface 202 is in the top view of Fig. 6B better shown, and is formed generally U-shaped.

Fig. 6A shows a particular option for any support structure 200 disclosed herein. The support structure 200 comprises a front panel 218. At or near a top end of the front panel 218, or at least above the working surface 202, one or more hook connection members 220 are provided to which for example a hook of a hooklift, cable lift or chain lift can be connected. Alternatively, a cable of a crane or winch can be connected to a hook connection member 200.

Another connection member 222, or preferably a plurality of connection members 222 provided at opposite sides of the support structure 200 - as indicated in Fig. 6B - may be optionally comprised by any support structure 200 disclosed herein. One or more cable or hooks can be connected to a connection member 222, for example for positioning the support structure 200 relative to a vehicle 300. The connection member 222 are preferably positioned below the hook connection member 220. As generally depicted in Fig. 6A, it is envisioned that in examples and situations, a protruding part 608 of the underground structure 606 protrudes above ground level defined by the surface 104 surrounding the hole 106. Even situations are envisioned wherein the protruding part 608 protrudes above the working surface 202. In such cases, a working surface 202 with the notch 216 may be preferred as the support structure 200 can then be moved into position while the protruding part 608 moves through the notch 216.

Figs. 7 A and 7B schematically show a soft surface site 700 wherein a structure 700 for production of natural resources protrudes from ground level, respectively in a section view and a top view. The structure 700 is at least partially surrounded by soft surface 704. Generally, soft surface 704 may be defined as any surface in which equipment and/or personnel may sink due to their weight. Examples of soft surface are mud, sand, farmland, unpaved surfaces, or any other soft surface.

The structure 700 may for example be used for obtaining salt from an underground source using solution mining. As such, the structure 700 may be a well head through which water can be pumped underground, and extracted after salt is dissolved in said water. It will be understood that the support structure 700 may be used in a method of abandoning or decommissioning the structure 700.

When the support structure 200 is positioned such that the working surface 202 is positioned adjacent to the structure 700, the structure 700 can now be accessed using equipment and/or personnel which would otherwise would sink in the soft surface 704. Thus, as with the support structure 200 used to span a well cellar, hole or ditch discussed above, it also envisioned to use the support structure to span an area of soft surface.

Preferably, but not necessarily, the working surface 202 has a notch 216 therein through the structure 700 can move while positioned the support structure. An arrow D in Fig. 7B generally indicated a direction in which the support structure 200 may be moved while being positioned. The support structure 200 may as in other embodiments disclosed herein be rolled off a vehicle, tilted down, and subsequently fully placed on the soft surface 704.

In the description above, it will be understood that when an element is referred to as being connect to another element, the element is either directly connected to the other element, or intervening elements may also be present. Also, it will be understood that the values given in the description above, are given by way of example and that other values may be possible and/or may be strived for.

It is to be noted that the figures are only schematic representations of embodiments that are given by way of non-limiting examples. For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the disclosure may include embodiments having combinations of all or some of the features described.

The word ‘comprising’ does not exclude the presence of other features or steps. Furthermore, the words 'a' and 'an' shall not be construed as limited to 'only one', but instead are used to mean 'at least one', and do not exclude a plurality.