Decommissioning offshore oil and gas wells
First Claim
1. A method for decommissioning an offshore oil or gas platform, comprising the steps of:
- a) providing a jack up rig, the jack up rig being equipped with one or more of an accommodation block, drilling mud supply and power supply, wherein the jack up rig has a cantilever structure extending over a side of the jack up rig, on which structure is mounted a first decommissioning rig tower;
b) maneuvering the jack up rig alongside the platform such that the cantilever and first decommissioning rig tower overlie a first well within a well bay of the platform;
c) installing on the platform a second decommissioning rig tower overlying a second well in the well bay of the platform; and
d) operating simultaneously the first and second decommissioning rig towers and associated equipment with one or more of power, drilling mud and operator personnel from or housed on the jack up rig.
1 Assignment
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Accused Products
Abstract
Method and structures perform decommissioning of offshore oil and gas platforms with associated wells. By installing on a platform (1) a movable decommissioning rig tower (2) but stripping away most of the other structures and equipment on the platform (1), and specifically not providing supporting resources such as drilling mud and power, accommodation, etc. on the platform, it is possible for both the rig tower (2) and a further rig tower (28) installed on a jack up rig (20) located alongside the platform (1) to access the well bay (5) of the platform. Thereby, two wells may be accessed simultaneously through the same well bay (5) and respective decommissioning operations carried out simultaneously and independently.
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Citations
12 Claims
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1. A method for decommissioning an offshore oil or gas platform, comprising the steps of:
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a) providing a jack up rig, the jack up rig being equipped with one or more of an accommodation block, drilling mud supply and power supply, wherein the jack up rig has a cantilever structure extending over a side of the jack up rig, on which structure is mounted a first decommissioning rig tower; b) maneuvering the jack up rig alongside the platform such that the cantilever and first decommissioning rig tower overlie a first well within a well bay of the platform; c) installing on the platform a second decommissioning rig tower overlying a second well in the well bay of the platform; and d) operating simultaneously the first and second decommissioning rig towers and associated equipment with one or more of power, drilling mud and operator personnel from or housed on the jack up rig. - View Dependent Claims (2, 3, 4, 5)
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6. A method for decommissioning an offshore oil or gas platform, comprising the steps of:
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providing a jack up rig, the jack up rig being equipped with one or more of an accommodation block, drilling mud supply and power supply, wherein the jack up rig has a cantilever structure extending over a side of the jack up rig, on which structure is mounted a first decommissioning rig tower; maneuvering the jack up rig alongside the platform such that the cantilever and first decommissioning rig tower overlie a first well within a well bay of the platform; installing on the platform a second decommissioning rig tower overlying a second well in the well bay of the platform; operating the first and second decommissioning rig towers and associated equipment with one or more of power, drilling mud and operator personnel from or housed on the jack up rig; and moving one of the first and second decommissioning rig towers to overlie a third well in the well bay and commencing a down hole operation in the third well whilst the other of the first and second decommissioning rig towers is performing a down hole operation.
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7. A combination of an offshore oil or gas platform being subject to decommissioning and a jack up rig, wherein:
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a) the jack up rig is equipped with one or more of a drilling mud supply and power supply, and the jack up rig has a cantilever structure extending over a side of the jack up rig, on which structure is mounted a first decommissioning rig tower; b) the jack up rig is located alongside the oil or gas platform such that the cantilever and first tower overlie a first well within a well bay of the platform; c) the platform is equipped with a second decommissioning rig tower overlying a second well in the well bay of the platform; and d) the second decommissioning rig tower is operable using one or more of the drilling mud supply and power supply from the jack up rig, wherein the first and/or second decommissioning rig tower is capable of being moved whilst the other of the first and second decommissioning rig towers is performing a down hole operation. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification