Patent Application
20190162048
The field of the invention is magnetic fishing tools and related methods and more particularly where the flow can be directed down to the fish and then redirected for circulation above the magnet during retrieval of the fish.
At times magnetic objects need to be removed from a borehole in a process called fishing. These operations typically involve fluid movement for debris agitation around the object to be retrieved known as the fish. Magnets are used to bring a connection close to the fish with the hope of engaging the fish in a way that will allow it to be pulled out of the hole and retained for the trip up the hole to the surface. Other applications simply use magnets to capture debris loosened by cleaning devices. These designs are illustrated in U.S. Pat. No. 5,348,086; US20130000884; U.S. Pat. Nos. 8,689,877; 6,357,539 (FIG. 7); U.S. Pat. Nos. 6,629,562; 3,905,631 and 4,059,155.
One issue with the prior designs is that they either lacked a circulation path altogether or their circulation path was exclusively downwardly oriented toward the fish. The idea was to disperse debris to facilitate dispersal of debris around the fish to enhance the chance of grabbing the fish for the trip out of the hole. The flow regime was always deployed in a single direction and this allowed the suspended debris to settle back down as the fish removal was attempted. The present invention addresses this shortcoming in the prior design by allowing the flow direction to be changed from the time up to engagement of the fish until the time it is desired to bring out the fish. The flow direction is changed from straight down toward the fish to laterally or uphole orientation to disperse or fluidize debris ahead of the fish to enhance the removal of the fish and minimize the chance of getting the fish stuck on the way out of the hole. To make this happen a flow through valve member is positioned to block lateral or uphole flow until the fish is engaged. Thereafter, the valve member can be activated with higher flow or a dropped object on a seat to shift the valve member and open ports that will direct flow laterally or in an uphole direction to aid the removal process for the fish. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings with the understanding that the full scope of the invention is to be determined from the appended claims.
The magnetic fishing tool has an axial flow passage through a valve member and one or more magnets for initial dispersal of debris away from the fish. Once engaged to the fish the flow direction can be altered by moving the valve member to open lateral ports and to close the straight through path so that fluid circulates above the fish to clear debris from ahead of the fish on the trip out of the hole. This can be accomplished with an object landed on a seat in the valve member, which causes it to shift axially to expose the lateral ports. Optionally the valve member can be shifted with flow in which case the flow will continue axially as well as laterally for the retrieval of the fish.
During running in the lateral ports 30, three of which are visible in the section view of
Those skilled in the art will appreciate that the magnetic fishing tool described above has the capability to switch flow direction through its body so that going in the hole the flow is directed downwardly toward the fish and after a grip is obtained the flow orientation can be reoriented to circulate out above the fish either laterally or in an uphole direction to keep debris fluidized ahead of the fish as the fish is brought out of the hole. It is preferable to cut off flow going straight through the tool with the fish engaged as that reduces the chances of the fish becoming dislodged from the tool on the way out of the hole. The magnets help with alignment of the body with the fish so that a grip can be obtained by a tool connected near the magnets or by a thread on the magnetic fishing tool engaging the fish directly. The change of flow configuration can also be accomplished in a variety of ways such as a pressure actuated indexing device that is capable of opening ports 30 and closing them multiple times if it is necessary to change the direction of the flow exiting body 10 more than once. The flow diverter device can move axially or turn or both to redirect flow from axial to lateral or in an uphole direction. It can be moved with a shift tool or without well intervention. Different types of magnets can be used although permanent magnets are preferred for simplicity and to avoid the provision of power to tool.
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:
