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Combined sucker rod fishing tools combine fishing tool of fishing sucker rod ontology with the fishing tool of coupling and ledge of fishing sucker rod, to form a new-type fishing tool.
Its application is without replacing slips, within oil pipe, sucker rod fishing tools ontology or ledge and coupling of fishing sucker rod, a multiple and efficient combination tool of fishing sucker rod.
Combined sucker rod fishing tools are composed of top and bottom parts.
1. Upper shell is exclusively for fishing sucker rod ontology, composed of top connection, upper shell, spring, spring seat, small slip, etc.
Top connection: the top has a joint buckle connecting to the sucker rod fishing tool, the bottom has external thread connecting to the upper shell, bore slides and coordinates with spring seat, and a small through-hole is used for inside and outside connectivity, to exclude dead oil.
Upper shell: the top's thread connects to the top connection, the bottom has a length of the internal conical surface, and the external thread at the bottom connects to the lower shell.
Spring seat: spring is put on the seat, seat coordinates to slide within the bore of top connection, and impacts small slip under the spring function.
Small slip: split structure, internal processing has grabbing thread and tooth, the external of sucker rod fishing tool is a cone with the same taper of the shell.
2. Lower shell
Coupling and ledge of sucker rod fishing tool have a similar structure to that of the upper shell, composed of the lower shell, spring housing, spring, big slip, etc.
Lower shell: the top of the sucker rod fishing tool has thread connecting to the upper shell, the internal top has a mating hole in spring housing, the middle is the inner cone, and the bottom's bore leads fishing.
Spring: due to design size, sucker rod suppliers adopt spiral spring of rectangular section.
Spring housing: installed within the shell, and can stabilize spring.
Big slip: same as small slip.
1. Fishing sucker rod ontology
During tool descent process, if meet sucker rod ontology, ontology enters into the upper shell through the lower shell, then gets into the small slip, under the function of spring, slip's male cone is identical with an inner cone of sucker rod fishing tool's shell, and internal thread of slip stays close to the external fishing surface.
When pulling fishing tool, by friction, fishing with slip moves down opposite to shell, internal cone within shell forces split bivalve slip to produce radial clamp force, to bite fishing.
2. Ledge or coupling of fishing sucker rod
Fishing imports through lower shell and presses against slip's front chamfer. Along with tool devolution, fishing props up bivalves, and slip enters into and through slip. Pull up sucker rod fishing tool, fishing with slip moves relatively to shell and forms radial clamp force, part of fishing's cambered surface is bite by a slip or stuck on the ledge of slip's seam allowance.
1. Operational approach
(1) Connect combined sucker rod fishing tools to the selected pipe column and descend the well.
(2) When pipe column down to the fish top, lower the sucker rod fishing tools slowly, and rotate 3 to 5 circles, in order to bring in fishing.
(3) When the weight indicator's pointer falls back, stop lowering and pull up slowly; if the weight indicator's index surpasses the original weight, it explains that fishing tools catch fishing.
(4) Pull out of the hole
2. Points for attention
(1) Before sucker rod fishing tools run in the hole, know well the shape and size of the fish top, and select the corresponding tool.
(2) Tighten tools and tool string.
(1) After use, disassemble, clean, and check all the parts, and replace damaged parts timely.
(2) During assembly, oil all the parts, and paint little butter on the spring seat and joint bore of the upper shell as well as spring housing and joint bore of the lower shell, in order to make sure that sucker rod fishing tools slide well.
