NO20200254A1 - A petroleum well casing or tubing pipe recovery system and a method for pipe recovery - Google Patents

Description

Title: A petroleum well casing or tubing pipe recovery system and a method for pipe recovery

Introduction

The present invention is a petroleum well casing or tubing recovery system. More specifically, casing or tubing being pulled out of a well is flattened in a continuous process rather than being broken out into separate pipe stands. The resulting flattened casing belt may be wound up to a casing belt coil.

Problems of prior art

During an oil or gas well Permanent plug and abandonment or Slot Recovery, pipe (tubing or casing) has to be removed to facilitate for required barriers dictated by government regulations. Tubing is also often recovered from wells.

Tubing may typically have dimensions 23/8 '' to 41/2 '' or up to 51/2 '' and are used in well completions in a casing pipe. Casing pipe extends from the surface to its intended depth. Casing pipe most often requiring to be pulled out is 95/8'' or 133/8''.

Traditionally this is done by the main rig, Derrek, removing one by one pipe by unscrewing or cutting in to specific lengths. The lengths are determined by the handling capacity of the rig, usually into stands of 3 x 12 m casing pipe. This is a time consuming operation, due to several thousand meter length of the pipe. Also the fact that each time a pipe stand length is recovered, the top drive will have to travel down to pick up the next pipe. Rigs have to spend hundreds of hours doing nonproductive work. Drilling a well is productive work.

The used pipe to be removed is being pulled by the hoisting mechanism of a derrick is in the background art and the hoisting is halted for each "stand" of 3 pipe sections and the stands are broken out into casing sections and stored in the pipe rack. Storing generally hollow, empty casing stands of Ø 95/8 (244 mm) and length 3 x 12 m and wall thickness about 10 mm, occupies a large, generally empty volume in the stored casing stands, which have no operational value but shall only be exported for steel recovery. The background art process is costly, slow, and time-savvy.

NO20150945A1 describes a device for well intervention by means of a coiled tubing and a wireline. The device comprises a cantilever adapted to be arranged on a vessel that is configured to be brought to a petroleum well at sea. The device further comprises a displacement arrangement, a first feeding device for feeding the coiled tubing and a second feeding device for feeding the wireline.

WO0026500A1 describes a method for expanding an expandable steel tubular comprises the steps of: flattening the unexpanded tubular; transporting the flattened unexpanded tubular to a location at or near the site where the tubular is to be installed; unflattening the tubular before positioning the tubular at said site; and expanding the tubular along at least a substantial part of its length before or after the tubular has been positioned at said site.

Brief Figure captions

The invention is illustrated in the attached drawing Figures, wherein

Fig. 1 is a vertical section of a well and a surface platform (marine or land) with at least one casing (or tubing) (00) in the well, with a pulling mechanism (10, 11) arranged for pulling out the casing or tubing (00) from the well. A casing or tubing (00) such as 95/8'' which has been cut by a cutting tool and released from possible cement and arranged in an enveloping casing 133/8''. Tubing may be pulled from a casing. The cylindrical casing pipe (00) being pulled up out of the well in a continuous manner is then according to the invention run between two flattener rollers (10), also in a continuous manner, e.g. in a length of 100m to 500m. The flattened casing or tubing belt (12) is conveyed along a conveyor mechanism (30) to a coil drum (20) which winds up a casing or tubing belt coil (14). This casing or tubing belt coil (14) is then exported as waste steel for smelting and re-use.

Fig. 2 is a steeply oblique view from point (A) of Fig. 1, and shows in part perspective view the rollers of an underlying pipe pulling mechanism feeding the up coming casing or tubing pipe (00) up to the above flattener rollers (10) which flattens the cylindrical casing or tubing pipe (00) to an up coming flattened pipe belt (12).

Brief summary of the invention

The invention is defined in the attached set of claims. Embodiments of the invention is defined in the dependent claims.

There are significant advantages of the invention:

The invention relates to removal of a string of pipe used to produce oil and gas (tubing) or pipe used to support the borehole (casing) in oil or gas well. The Invention can be used to recover/remove any pipe from a wellbore more efficient than current methods used when performing permanent plug and abandonment and Slot Recovery of wellbores.

Moving this pipe recovery operation to an offline activity and/or reducing time spent to recover pipe will have an enormous impact on well cost. Reducing main rig activity in Permanent plug and abandonment and/or Slot Recovery of wellbores will have a huge impact on oil or gas well cost.

The pipe (00) may be pulled in a continuous process out of the well. The pipe (00) is not halted for each "stand" of 3 pipe sections and the stands broken out into casing sections and stored in the pipe rack, but contiunously flattended and wound up on a coil drum. This saves much storage space in the pipe rack, and allows the resulting compact casing or tubing belt coil (14) of far less volume than corresponding stored casing or tubing stands, to be exported for steel recovery elsewhere. The process saves time and space.

The process of the present invention may be done on a free well slot while active well operations such as drilling, whipstock operations, cementing, etc. is conducted on another well slot. In this manner, the present invention saves time, too.

Embodiments of the invention

The invention is a petroleum well casing or tubing pipe recovery system comprising

- a pipe pulling mechanism (11) arranged for pulling casing or tubing pipe (00) out of a well,

- with a set of two or more flattener rollers (10) arranged for engaging with the emerging casing or tubing pipe (00) being pulled from the well, and flattening the casing or tubing pipe (00) to a flattened pipe belt (12). Further, the recovery system has a conveyor mechanism (30) arranged for conveying said pipe belt (12) away from said well.

(In a very simple embodiment of the invention, the flattended casing belt (12) could, when being conveyed away from the well, be cut up into lengths and stored in their flattened straight state. pulled casing or tubing pipes are hollow pipes of equal diameter, which usually are stored broken up in lengths of three and three joints of 12 metres in a pipe stack outside the V-port of the derrick. Flattended straight pipes would constitute a far more compact storage space than their corresponding pipes. However, cutting the flattened pipe belt is a process we would like to avoid in the present invention, so we go a bit further.)

In an embodiment of the invention, the conveyor mechanism (30) is arranged for conveying said pipe belt (12) away form said wall and to a coil drum (20), whereby the coil drum (20) is arranged for winding up said flattened pipe belt (12) to a pipe belt coil (14). Then the pipe belt coil (14) could be transported away as steel recovery waste.

In other words, the invention is a method for petroleum well casing or tubing pipe recovery comprising the steps of:

- pulling casing or tubing pipe (00) out of a well by means of a pipe pulling mechanism (11), - flattening said casing or tubing pipe (00) to a flattened pipe belt (12) using a set of two or more flattener "squeeze" rollers (10),

- conveying the resulting pipe belt away from the well using a conveyor mechanism (30) - receiving said pipe belt (12) on a coil drum (20),

- winding up said flattened pipe belt (12) to a pipe belt coil (14),

transporting away said pipe belt coil (14) for steel waste recovery.

In one aspect, this would resemble coiled tubing, but with a significant difference: Coiled tubing is usually stored on large-radius drums so as for avoiding bending the coiled tubing to a radius smaller than the elastic limit of the tubing, in order to avoid irreversible deformation to the tubing. In the present invention, plastic deformation of the casing or tubing is no problem because it shall be sent to steel recovery and not direct re-use as casing or tubing pipe. Thus the radius of the coil drum (20) may be as small as otherwise desired by the mechanical designer, without regard to the deformation of the pipe belt (12) to a pipe belt coil (14). Coiled tubing is useful steel for being fed into a well, wherein its properties must be maintained. Used casing or tubing taken out of a well is waste, and may be handled in a way resulting in permanent deformation.

In an embodiment of the invention the squeeze rollers (10) also constitutes said pulling mechanism (11), i.e. that the same rollers (10) which flatten the casing or tubing also pull the casing or tubing pipe (00) up from the well. This is shown in part of the drawing.

In another embodiment of the invention, also shown in the drawing, the set of two or more flattener rollers (10) are arranged separately and above said pulling mechanism (11). The pipe pulling mechanism may be a set of two or more gripping and pipe pulling rollers (11) or belts, with some rugged friction mechanism such as studs, for engaging the casing or tubing (00) before it reaches the deformation zone of the flattener rollers (10). The pulling rollers (11) would be arranged enveloping the casing or tubing (00). This would ensure that the casing or tubing (00) is evenly pulled and held even if the casing or tubing should partly or entirely disassemble in the threaded joints usually separated by 12 metres for the casing example. Then the flattener rollers (10) have the separate role of flattening the casing or tubing pipe and the threaded casing or tubing joints to a flattened pipe belt of small thickness. The casing or tubing joints will form thickened portions of the belt, but would otherwise be flattened, too. The flattended casing or tubing joints would be more or less randomly distributed around and inside the resulting band coil (14).

In an embodiment of the invention the flattening rollers (10) are driven by a motor (M1, 15). The motor (M1, 15) or a separate motor (M2) may drive the pulling rollers (11). In an embodiment of the invention the flattening rollers (10) are provided with studs (101) for engaging the casing or tubing pipe (00), and so may the pulling rollers (11) have.

Claims (8)

Claims

1. A petroleum well casing or tubing pipe recovery system

comprising

- a pipe pulling mechanism (11) arranged for pulling casing or tubing pipe (00) out of a well,

- a set of two or more flattener "squeeze" rollers (10) arranged for flattening said casing or tubing pipe (00) to a flattened pipe belt (12),

- a conveyor mechanism (30) arranged for conveying said pipe belt (12) away from said well.

2. The petroleum well casing or tubing pipe recovery system of claim 1,

- said conveyor mechanism arranged for conveying said pipe belt (12) away form said wall and to a coil drum (20),

- said coil drum (20) arranged for winding up said flattened pipe belt (12) to a pipe belt coil (14), - said pipe belt coil (14) for being transported away as steel recovery waste.

3. The petroleum well casing or tubing pipe recovery system of claim 1 or 2,

- wherein said squeeze rollers (10) also constitutes said pulling mechanism (11), i.e. that the same rollers (10) which flatten the casing or tubing also pull the casing or tubing pipe (00) up from the well.

4. The petroleum well casing or tubing pipe recovery system of claim 1 or 2,

- wherein said set of two or more flattener "squeeze" rollers (10) are arranged above said pulling mechanism (11).

5. The petroleum well casing or tubing pipe recovery system of any of the preceding claims,

- wherein said flattening rollers (10) are driven by a motor (15).

6. The petroleum well casing or tubing pipe recovery system of any of the preceding claims,

- wherein said flattening rollers (10) are provided with studs (101) for engaging the casing or tubing pipe (00).

7. The petroleum well casing or tubing pipe recovery system of any of the preceding claims, - wherein said flattening rollers (10) are arranged as a parallel pair with generally horizontal axes (110), i.e. the axes (110) are arranged transverse to the axis of the out coming casing or tubing pipe (00).

8. A petroleum well casing or tubing pipe recovery method

comprising the steps of

- pulling casing or tubing pipe (00) out of a well by means of a pipe pulling mechanism (11), - flattening said casing or tubing pipe (00) to a flattened pipe belt (12) using a set of two or more flattener "squeeze" rollers (10),

- conveying the resulting pipe belt away from the well using a conveyor mechanism (30)

- receiving said pipe belt (12) on a coil drum (20),

- winding up said flattened pipe belt (12) to a pipe belt coil (14),

transporting away said pipe belt coil (14) for steel waste recovery.