Patent Application
20130043021
The field of the invention is vibrators for subterranean use and more particularly vibrators that function through flow in a string and more specifically where there is a lateral component to the vibration.
Vibration can be a cause or a solution of problems in subterranean locations. It can be a quantity that has to be controlled so that equipment or drill strings do not fatigue. It can be a force that creates acoustic signals that can be sensed in a variety of situations to monitor well conditions as for example in U.S. Pat. No. 5,080,189. It can be used to advantage to advance screens into a gravel pack using an augur in combination with a vibrator as shown in U.S. Pat. No. 6,877,561. Vibrators can be configured to pass tools until needed to function as a vibrator as shown in U.S. Pat. No. 6,866,104.
Typically, a vibrator is used in a tool string being run in to avoid getting stuck or to try to get the string to release if it gets stuck for a variety of reasons such as hole collapse in open hole when advancing through unconsolidated formations. One such vibrator whose basics will be discussed in detail below is U.S. Pat. No. 6,474,421. Other relevant art includes U.S. Pat. Nos. 7,575,051; 6,675,909 and 7,264,055.
a-1c are a simplified half section presentation of the vibrating tool in U.S. Pat. No. 6,474,421 that provides flow induced axial vibration. The string 10 supports the housing 12. There is a flowpath 14 with a movable dart valve 16 in the flow path 14. The dart valve 16 has a closed nose 18 and lateral outlets 20. A spring 22 bears on shoulder 24 in the housing 12 to push the dart valve 16 uphole and in an opposite direction as the flow from the surface represented by arrow 26. An impact sleeve 28 is biased uphole by spring 30 supported from surface 32 in housing 12. Flow from the surface, represented by arrow 26 moves the dart valve 16 toward the impact sleeve 28. Initially the nose 18 contacts the impact sleeve 28 to stop flow and to initiate tandem movement of the dart valve 16 and the impact sleeve 28. Both springs 22 and 30 are compressed as this happens. The dart valve 16 is abruptly stopped by shoulder 34 for a downhole oriented axial pounding blow and the dart valve 16 separates from the impact sleeve 28. This opens a gap between the dart valve 16 and the impact sleeve 28 so that flow can start again. With the onset of flow, the spring 30 drives up the impact sleeve 28 against the shoulder 36 for a jarring uphole blow in the axial direction.
While this design has worked well it is limited by the axial direction of the opposed vibration impacts as the tool cycles continuously as described above with the flow continuing. What is needed and provided by the present invention is a way to also provide lateral vibration in conjunction with the axial vibration while still keeping the device simple for continuing trouble free operation. Those skilled in the art will better appreciate the present invention that provides vibration in lateral directions as well as axial vibration for more effective release of stuck strings or to better prevent sticking in the first place by a review of the description of the preferred embodiment and the associated drawings while at the same time realizing that the full scope of the invention is to be determined by the appended claims.
A vibratory tool for use in a tubular string to prevent sticking or to release a stuck string features a fluid operated dart valve working in conjunction with an impact sleeve to deliver continuous axial jarring blows in opposed directions as long as flow is maintained. Movement of one of those components axially in opposed directions opens and closes access to opposed lateral ports so that a lateral vibration is also established as flow cyclically occurs and stops sequentially at opposed lateral outlets.
a shows the position of the parts as the dart valve starts moving in response to flow in a prior art design;
b is the view of
c is the view of
Referring to
The operation of the vibrator is as follows. Flow represented by arrow 44 goes through ports 52 and starts the dart valve 48 moving against the force of spring 60. Preferably the nose 50 contacts the impact sleeve 54 first to cut off flow, represented by arrow 72, to the lower lateral port 70. Movement of the dart valve 48 toward the impact sleeve 52 not only cuts off flow 72 but it also exposes upper lateral port 64 as seal 66 moves past the port 64 as shown in
Note that movement of the dart valve 48 and impact sleeve 54 past the
As a result the lateral ports 64 and 70 are sequentially used for flow to establish a lateral vibration pattern in the housing 40 to aid in getting the housing 40 and the attached string such as a drill string unstuck or to prevent the housing 40 from sticking at all. It should be noted that depending on the part configurations the ports 64 and 70 can be open sequentially or they can have some overlap as the lateral flow regime switches back and forth. The openings 64 and 70 can be in a single or multiple rows and the opening sizes as between openings 64 and 70 can be the same or different. The arrangements at either end can be ordered or random and all the openings 64 can be the same size or different sizes. The openings can be centered at 90 degrees to the axis of the housing 40 or the center axis could be shifted so that it doesn't cross the axis of the housing 40, such as in
Optionally, the nose 50 can have a seat 74 around a passage 76 that stays open so that tools can pass through the vibrator until it needs to be deployed. When it is time to activate the vibrator an object 78 is landed on seat 74 to close off passage 76 and the operation from there is the same as described above for a solid nose 50.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
