Wells – Processes – Placing or shifting well part
Reexamination Certificate
1998-10-09
2001-01-16
Suchfield, George (Department: 3672)
Wells
Processes
Placing or shifting well part
C166S050000, C166S065100, C166S066000, C166S385000, C073S152170, C073S865800, C073S866500, C405S154100
Reexamination Certificate
active
06173787
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a system and to a method for measurement and/or servicing in wellbores or in pipes. The method is particularly well-suited to pipes comprising a substantially horizontal portion of rather great length.
BACKGROUND OF THE INVENTION
In the field of well logging, there are several well-known methods for displacing measuring instruments in greatly inclined or even horizontal pipes. It is possible to use drill rods made up end to end and equipped with a transmission cable placed in the inner space thereof, a continuous steel tubing (cabled coiled tubing) also comprising a transmission cable, or mechanical means for displacing measuring tools, such as hydraulically, electrically or electro-hydraulically-powered tractors. Measuring probe tractors are generally fed by an electric cable which supplies electric power to an electric motor driving a high-pressure hydraulic pump. The high-pressure hydraulic fluid actuates wheels placed against the wall of the well or of the pipe. The tensile or thrust force is of the order of 5 to 10 kN. These tractors are mechanically complex and costly because they cannot be too heavy, but they must however withstand the high pressures and temperatures to which they can be subjected in the pipe. Furthermore, the tensile strength of the electric feeder cable does not allow an excessive weight of the tractor. The power supply that can be transmitted is also limited. Moreover, the tensile or the thrust capacity depends on the coefficient of friction between the driving wheels and the wall of the pipe. This explains notably the relatively limited thrust or tensile capacities considering the weight of the feeder cable, the weight of the tractor itself and the weight of the tools to be displaced by the tractor. A conventional logging cable has a steel armouring with a rather high linear weight and wall friction coefficient. When a certain cable length is horizontal, the force of the tractor may not be sufficient to displace the total load. Furthermore, tractors cannot work in open holes because the rugosity of the rock face does not allow correct and effective contact of the driving wheels. Using a continuous coiled tubing equipped with an inner logging cable does not eliminate these drawbacks, on the contrary, because the linear weight thereof is even greater. Furthermore, the surface installation for maneuvering a coiled tubing is bulky and very costly.
SUMMARY OF THE INVENTION
The present invention thus relates to a system for displacing instruments in a pipe comprising a portion greatly inclined to the vertical. The system comprises in combination: a set of instruments mechanically linked to a first end of electrically-powered displacement means, a semi-rigid composite rod that can be wound round a drum and comprising at least one electric conductor. One end of the rod is fastened to the second end of said displacement means.
The instruments can comprise measuring sondes or probes, cameras, packer, plug or valve type well equipments, wall perforation tools.
The other end of the semi-rigid rod can be wound round a drum outside the pipe.
The pipe can comprise a portion sufficiently inclined to allow weights to move under the effect of gravity, and weighting bars can be connected to the other end of the semi-rigid rod, the bars being suspended in the pipe by a cable wound round a winch outside the pipe.
Extension means of determined length can be interposed between said displacement means and said instruments.
The extension means can comprise a semi-rigid rod length.
The present invention also relates to a method for displacing instruments in a pipe comprising a portion greatly inclined to the vertical. The method comprises the following stages:
fastening a set of instruments to a first end of electrically-powered displacement means,
connecting an end of a semi-rigid composite rod that can be wound round a drum and comprising at least one electric conductor to a second end of said displacement means,
displacing said set in the pipe through a combined thrust action by means of the rod and of the displacement means.
In the method, said thrust can be exerted by means of the rod by actuating mechanical means for injecting the rod into the pipe.
The thrust can be exerted by means of the rod by fastening weighting bars to the other end of the rod, and by suspending said bars in the pipe by a logging type cable.
Extension means of determined length can be interposed between said instruments and said displacement means.
The method according to the invention can be applied to oil wells comprising a substantially horizontal portion.
In a variant, the method can be applied when the well comprises a lateral hole.
The method can be applied to inspection or control operations in rigid or flexible lines.
REFERENCES:
patent: 3401749 (1968-09-01), Daniel
patent: 4485870 (1984-12-01), Walulik
patent: 4676310 (1987-06-01), Scherbatskoy et al.
patent: 4901804 (1990-02-01), Thometz et al.
patent: 4951758 (1990-08-01), Sonku et al.
patent: 5111880 (1992-05-01), Wittrisch et al.
patent: 5184682 (1993-02-01), Delacour et al.
patent: 5353872 (1994-10-01), Wittrisch
patent: 5505259 (1996-04-01), Wittrisch et al.
patent: 5947213 (1999-09-01), Angle et al.
patent: 6003606 (1999-12-01), Moore et al.
patent: 195 34 696 (1997-03-01), None
patent: 0 352 148 (1990-01-01), None
patent: 2 240 566 (1991-01-01), None
patent: 93/18277 (1993-09-01), None
patent: 98/02634 (1998-01-01), None
patent: 98/12418 (1998-03-01), None
Østvang, K.,et al., “Wireline tractor operations successful in horizontal wells,”World Oil,vol. 218, No. 4, Apr. 4, 1997, pp. 125-126, 128, 130, 132.
“Downhole tractors expand extended reach possibilities,”Offshore,vol. 55, No. 8, Aug., 1995, p. 28.
Institut Francais du Pe'trole
Millen White Zelano & Branigan P.C.
Suchfield George
LandOfFree
Method and system intended for measurements in a horizontal... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system intended for measurements in a horizontal..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system intended for measurements in a horizontal... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2462751