Laser systems and methods for the removal of structures

An offshore method of cutting material associated with an offshore structure comprising:

• a. positioning a high power laser system over a body of water and proximate to a location of an offshore structure, the high power laser system comprising a high power laser and a high power laser cutter assembly;
• b. the high power laser cutter assembly defining a laser beam delivery path for delivery of a high power laser beam along the beam delivery path;
• c. propagating a high power laser beam along the beam delivery path, the laser beam having a power of at least 5 kW;
• and,
• d. changing a relative position of a material to be sectioned and the laser beam path in a predetermined laser beam delivery pattern, whereby the laser beam cuts the material in a predetermined cut.

A method of cutting material associated with an offshore structure comprising:

• a. positioning a high power laser system proximate to an offshore structure in a body of water, the high power laser system comprising a high power laser optically associated by an umbilical with a high power laser cutter assembly;
• b. the high power laser cutter assembly defining a laser beam delivery path for delivery of a high power laser beam along a beam path;
• c. positioning the beam path below a surface of a body of water;
• d. propagating a high power laser beam along the beam path below the surface of the body of water;
• and,
• e. changing a relative position of a member to be cut and the laser beam path, whereby the laser beam strikes the member below the surface of the body of water and thereby cuts the member below the surface of the body of water.

A method of plugging and abandoning a well using a high power laser system, the method comprising:

• a. selecting a well that extends below a surface of the earth, the well having tubulars contained within the well and at least one tubular extending from a location within the well below the surface of the earth to a location above the surface of the earth;
• b. determining a configuration of at least some of the tubulars;
• c. formulating a plugging and abandonment plan for the well based in part upon the configuration of at least some of the tubulars;
• d. the plugging and abandonment plan comprising:
• cutting a tubular at a predetermined location within the well and removing the tubular above the cut from the well;
• placing a plug within the well;
• cutting and removing all tubulars from the well at least about three feet below the surface of the earth;
• and,
• e. performing the cutting with a high power laser beam.

A method of plugging and abandoning a well using a high power laser system, the method comprising:

• a. selecting a borehole in a surface of the earth forming a well, the borehole having a tubular contained therein, the tubular extending below the surface of the earth;
• b. placing a first plug within the borehole;
• c. cutting the tubular at a location within the borehole and removing at least a some of the cut tubular from the borehole;
• placing a second plug within the borehole, the second plug being located closer to the surface of the earth than the first plug;
• d. delivering a high power laser beam along a beam path to cut all additional tubulars within the borehole at a second location above the second plug, wherein the delivery of the laser beam completely severs all the additional tubulars at the location within the borehole;
• and,
• e. removing all of the severed additional tubulars from the borehole above the second location, wherein the borehole above the second location is free from the additional tubulars.

A method of removing a conductor from a body of water using a high power laser system, the method comprising:

• a. positioning a high power laser cutting tool proximate a location on a conductor below a surface of a body of water;
• b. directing a high power laser beam along a beam path from the laser cutting tool to the location, wherein the laser beam severs the conductor at about the location, thereby creating a severed section of the conductor above the location;
• and
• c. raising the severed section of the conductor above the surface of the body of water.

A method of removing contamination from an offshore structure to lessen the weight of the structure, the method comprising:

• a. positioning a high power laser system over a body of water and proximate to a location of an offshore structure, the high power laser system comprising a high power laser optically associated with a high power laser delivery assembly;
• b. the high power laser delivery assembly defining a laser beam delivery path for delivery of a high power laser beam along the beam delivery path;
• c. positioning the beam delivery path between the delivery assembly and a location of the offshore structure;
• d. propagating a high power laser beam along the beam delivery path, the laser beam having a beam property;
• e. scanning the high power laser beam from a location on the offshore structure to a second location on the offshore structure at a scan rate, whereby the beam property and scan rate are such that contamination is removed from the offshore structure without substantial damage to the offshore structure.

A method of removing large heavy offshore structures from a body of water, without the need for heaving hoisting equipment, the method comprising:

• a. positioning a high power laser system over a body of water and proximate to a location of an offshore structure, the high power laser system comprising a high power laser optically associated with a high power laser delivery assembly;
• b. determining a laser cutting plan for cutting the offshore structure into sections of a predetermined size and weight;
• c. laser cutting the offshore structure below a surface of the body of water into a predetermined section;
• and,
• d. removing the predetermined section from the body of water.

A laser decommissioning, plugging and abandoning vessel comprising:

• a. a vessel;
• b. a high power laser having at least about 10 kW of power;
• c. a means for high power laser cutting;
• and,
• d. a means for optically associating the laser and the means for cutting

A mobile laser removal system, capable of being placed on a vehicle, vessel, platform, or offshore structure, the system comprising:

• a high power laser having at least 5 kW of power;
• and,
• a subsea high power laser cutting tool;
• and,
• an umbilical for optically associating the high power laser with the subsea high power laser cutting tool.

An underwater laser cutting tool, comprising:

• a laser tool body defining a longitudinal axis and comprising a conveyance termination section and an anchoring section;
• a stand-off distance setting device, whereby the laser tool body axis may be positioned in a predetermined location relative to an axis of a tubular to be cut;
• a motor section;
• a laser cutting head section, comprising a laser beam exit;
• and a laser optics defining an axis.

An offshore laser services system, capable of providing offshore laser decommissioning, plugging, abandonment, cleaning, or cutting services, the system comprising:

• a remote operated vehicle;
• a laser module;
• an umbilical;
• and, a laser cutting tool;
• whereby the system is capable of laser cutting offshore materials selected from the group consisting of mooring chains, subsea pipelines, jacket structures, piles, conductors, tubulars, and control umbilicals.