Subsequent to the drilling of an underground oil or gas well, if such a well is located within or on a platform, a drilling ship or the like, the well is completed by the introduction of a tubular pipe, which is referred often to as the “casing”. The casing is welded in place as part of the finishing operation.
Before or after the introduction of one or more sections of pipes that form the casing in the underground well, or the like, it may be required to perform several welding operations in one or more ends of the casing for the connection, for example, a leak preventer, heads, valves or other desirable components. It may be desired to fasten sections of each pipe of the casing. In many cases, such a component is fixed to the pipe members of the casing through welding operations by means well known in the industry.
As a result of the discharge of the flame from a welding plant, during the welding operation, sparks, slag and other inconveniences can be expected to be expelled in the air around the welding operation resulting in a serious risk during the welding operation. Slag and sparks could cause a fire or even worse, an explosion, as the casing is inserted often onto “live” wells, which sometimes could become uncontrollable at any time as a result of a breakdown or boiling of flammable liquids, such as natural gas or the like.
To address this danger, there is desired an enclosure that prevents or treats this problem by providing a habitat for welding in underground wells, which not only captures the slag and sparks during the welding procedure in an area which is isolated from the wellbore fluids, but the environment provides for controlled dissemination of slag and spark through habitat and away from the welding operation in a safe and controllable manner.
In the state of the art relative to that described above, there exists the following published documents: U.S. Pat. No. 2,872,933; U.S. Pat. No. 3,837,171; U.S. Pat. No. 3,946,571, U.S. Pat. No. 4,257,720; U.S. Pat. No. 5,018,321, Mexican Utility Model No. 1624 and Mexican Patent Application No. MX 308,953.
However, all these published documents have certain disadvantages and deficiencies that are accentuated when performing the welding process. As a result, it is desirable to make structural changes to these existing structures in order to provide greater benefits to workers and higher security to facilities where these activities are performed.
U.S. Pat. No. 2,872,933 relates to the construction of an air inflated ring cover which is used to cover drilling sites in oil wells, regardless of weather conditions. The cover is hanged by its top over the drilling site.
U.S. Pat. No. 3,837,171 relates to an underwater inflatable structure, which provides an artificial environment around a work area, for example, in a submarine base of an offshore oil platform, allowing for welding and the like to be performed. The structure comprises an integral sheet of material for a custom work or a number of selected sheets attached to the structural support elements. The material includes rack sections so that the material can be placed over and around the structural members in order to ensure a substantially airtight system. Neck sealing means are included on the structural members at their intersection with the sheet material and sealing means within the rack sections although the system could be used on land, it is particularly applicable to subsea situations.
U.S. Pat. No. 3,946,571 relates to an insulated module for use in environments with hostile temperatures that are uncomfortable for humans. This service module is lowered and put into service by the top of the module.
U.S. Pat. No. 4,257,720 relates to a capsule for works in the deep sea, allowing personnel access for maintenance work.
U.S. Pat. No. 5,018,321 discloses a flexible habitat for welding in underground wells to trap slag, sparks and the like. The habitat generally includes an air hanged external arched dome, which is mountable on an entry point of an underground well. The entry point of the underground well receives a pipe member which is extensible in the well and on which a process is carried out by welding. A fire resistant protective element is disposed about at least a bottom of the dome. Means are provided for selectively introducing air to hang the dome on the entry point. The means includes an air inductor motor, a fan, or the like. Means extend through the upper portion of the dome and away from the entry point to communicate with the inside of the dome to allow discharge of smoke including particulate matter, a result of welding procedure that is discharged from inside the dome. The means for introducing air and the means extending through an upper portion of the dome are aligned whereby the air supply forms a carrier stream for transmitting the smoke and particulate matter at least to the means extending through an upper portion of the dome, and preferably to transmit to and through the outside of the dome without the aid of any other means. The habitat also includes a fire resistant skirt which is available around the highest outermost portion of the pipe member. The guard is extended to ensure that the slag and the spark are not discharged downward around the outside of the casing or pipe member of transmission of fluid through the well. However, it has seen that in overworked hours, smoke and particulate waste is relatively excessive, tending to occlude the expulsion means of the habitat. This causes the worker to suffer significant health risks, and in the other hand, considerable costs are generated by the excessive change of filters which are arranged in the discharge means of the habitat.
Mexican Utility Model No. 1624 discloses a flexible habitat for welding in underground wells to trap slag, sparks and the like. The habitat generally includes an air hanged external arched dome which is mountable on an entry point of the underground well, which includes a ventilation system which is comprised basically of a structure porous sublayer arranged throughout the area comprising the dome of the habitat. The sublayer is releasably secured by conventional means, which serves as a filter.
However, upon conditions of use; particularly for U.S. Pat. No. 5,018,321 and Mexican Utility Model No. 1624, are not very favorable, as the degree of difficulty of assembling the structure in a work area is considerably high and dangerous, so the habitat of these two references are not suitable under the habitat occurs in one piece and resulting inconvenient to carry various habitat elements of different sizes. This causes the work schedules to be extended while the cost per hour/man rises considerably.
Mexican Patent No. 308953 and the state of the art cited, display wide shortcomings in their modularity to form the modular habitat and therefore reflect these deficiencies in the safety management to users and infrastructure where the modular habitat is used for working. These shortcomings are reflected in the management of tasks performed as the welding of tube. That is, in this reference, certain disadvantages are identified when performing the assembly process and adaptation in the workplace of the device for welding work, so the present invention overcomes these shortcomings by introducing structural changes in this habitat's modularity in order to provide greater benefits to the worker and the best development of the activities for which Flexible modular habitat was designed, while increasing the safety of workers and therefore infrastructure where the flexible modular habitat is installed.
In Mexican Patent No. 308,953, there is disclosed a flexible and inflatable habitat for welding in underground wells to trap slag, sparks and the like, by a module based structure and/or assembly. The structure allows different applications to fit different hot work applications without having to stop production. However, it has shortcomings by not hermetically sealing the contact of modular habitat with the element to be developed in works, so that security to the users and facilities is poor, and wherein it does not have security elements such as the emergency door.
A further advantage of the present invention over the art cited is the non-use of racks, stanchions or mechanical closures raised from “hard” devices or continuous use. Such lack of racks, stanchions or mechanical closures makes the current invention less susceptible to malfunction in assembly and disassembly of each the modules that form the flexible modular habitat. Thereby, the current invention increases the security provided within the modular habitat, by preventing the modules from separating or opening.