Wells – Processes – Freeing stuck object – grappling or fishing in well
Reexamination Certificate
2000-10-12
2003-01-07
Dang, Hoang (Department: 3672)
Wells
Processes
Freeing stuck object, grappling or fishing in well
C166S050000, C166S177600, C166S178000
Reexamination Certificate
active
06502638
ABSTRACT:
FIELD OF THE INVENTION
The field of this invention relates to techniques for improving the performance of fishing and drilling jars in deviated well bore conditions.
BACKGROUND OF THE INVENTION
The problem addressed by the method of the present invention is illustrated in FIG.
1
. Referring to
FIG. 1
a deviated well bore
10
is illustrated. The deviated well bore
10
has a 90° bend
12
. Further down in the well bore a stuck object or “fish”
14
is located. The fish
14
could be a liner string or a downhole tool. A jar
16
is secured to a tubing string
18
for ultimate attachment to the fish
14
. These jars require a significant amount of overpull and are known for their ability to deliver high impact blows to a stuck object. The frequency of the blows is quite low. However the magnitude of the force delivered is a multiple of the overpull force applied which can be in the order of tens of thousands of pounds or more.
FIG. 1
readily illustrates the problem when attempting to use this type of jar in the deviated well bore
10
. The tubing string
18
makes contact with the wall
20
of the well bore
10
. This impedes the degree of overpull that can be applied to the jar
16
and thus moderates the applied impact load to the fish
14
to free it. In essence the frictional forces at the bend
12
acting on the tubing string
18
limit the amount of tension that can be applied to the string
18
which is transmitted to the jar
16
.
One approach in the prior art has been to work the tubing string
18
up and down with the draw works at the surface. This technique has had very limited success.
Various high frequency vibratory devices have been used in tandem with rotating bits to promote drilling operations. Such techniques are illustrated in U.S. Pat. Nos. 4,462,471; 4,958,691; 5,156,223. Such high frequency vibratory tools have also been used to release stuck objects in the well bore by being attached directly to the stuck object. When fluid is pumped through such tools vibration ensues and the vibration hopefully frees the stuck object such as a liner string.
The object of the present invention is to alleviate the problems for applications of fishing and drilling jars which rely on significant amounts of applied overpull in deviated or horizontal well bores. Thus the objective of the present invention is to be able to ensure transmission of the applied overpull force at the surface to the jar which is in the deviated or horizontal segment of the well bore. Those skilled in art will readily appreciate how the objective of the method of the present invention is accomplished by a review of the preferred embodiment which appears below.
SUMMARY OF THE INVENTION
A method for using fishing and drilling jars which require high applied tensile loads in deviated or horizontal well bores is described. The method involves the placement of the string of high frequency vibratory devices that are triggered by flow therethrough. These vibratory devices are placed in the region of the bend or deviation in the well bore. The vibratory forces are applied coincidently with the tensile overpull force so as to fully utilize the applied overpull force at the surface down hole at the jar which is attached to the fish.
REFERENCES:
patent: 3235014 (1966-02-01), Brooks
patent: 3898815 (1975-08-01), Young
patent: 3946819 (1976-03-01), Hipp
patent: 4111271 (1978-09-01), Perkins
patent: 4384625 (1983-05-01), Roper et al.
patent: 4462471 (1984-07-01), Hipp
patent: 4576229 (1986-03-01), Brown
patent: 4682657 (1987-07-01), Crawford
patent: 4702325 (1987-10-01), Hipp
patent: 4890682 (1990-01-01), Worrall et al.
patent: 5007479 (1991-04-01), Pleasants et al.
patent: 5156223 (1992-10-01), Hipp
patent: 5562170 (1996-10-01), Wolfer et al.
patent: 5595244 (1997-01-01), Roberts
patent: 5722495 (1998-03-01), Rear
patent: 5762142 (1998-06-01), Connell et al.
patent: 6062324 (2000-05-01), Hipp
patent: 6152222 (2000-11-01), Kyllingstad
patent: 0 245892 (1987-11-01), None
patent: 2261238 (1993-05-01), None
patent: 2318374 (1998-04-01), None
patent: 2332690 (1999-06-01), None
patent: 2343465 (2000-05-01), None
Baker Hughes Incorporated
Dang Hoang
Rosenblatt Steve
LandOfFree
Method for improving performance of fishing and drilling... 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 for improving performance of fishing and drilling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for improving performance of fishing and drilling... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3062301