Large-range fishing spear and fishing method thereof

Abstract

The invention discloses a large-range fishing spear and a fishing method thereof. The large-range fishing spear comprises a mandrel, an upper sliding sleeve and a lower sliding sleeve, wherein the mandrel is sleeved with the upper sliding sleeve and the lower sliding sleeve. The mandrel comprises a spear rod, an upper connector and an adjusting sleeve, wherein the upper connector and the adjusting sleeve are connected to the upper end and the lower end of the spear rod correspondingly. Four split type slips are connected between the upper sliding sleeve and the lower sliding sleeve. T-shaped heads are arranged at the two ends of each split type slip correspondingly. T-shaped grooves are formed in the lower end of the upper sliding sleeve and the upper end of the lower sliding sleeve correspondingly. The T-shaped heads are clamped into the T-shaped grooves to connect the upper sliding sleeve and the lower sliding sleeve together. The split type slips can move radially on the spear rod so that fishing of downhole drilling tools of different diameters can be adapted, the fishing range is larger, and the large-range fishing spear further can be used when the diameters of the downhole drilling tools cannot be precisely determined; and meanwhile, mutually-matched double conic surfaces are arranged on each split type slip and the mandrel, so that the force-bearing contact area is increased, and fishing force is improved.

Description

technical field [0001] The invention relates to a large-scale fishing spear and belongs to the technical field of downhole fishing. Background technique [0002] "Salvage" refers to the treatment of oil and gas wells such as drill pipes and drill collars stuck, fishing out drill pipes that have been twisted or dropped due to other reasons, fishing out objects falling from the bottom of the well, fishing for broken or stuck cables, etc. process method. Whenever any of the above-mentioned problems occurs, normal drilling, workover and well completion work will be interrupted, and can only be resumed after the successful fishing operation. [0003] Salvage itself is a more flexible and changeable process. In many cases, there are several ways to deal with an accident. However, when all factors are taken into consideration, only one method may be the best method. Therefore, formulating a salvage plan is one of the most important stages, because the correct plan and tool combi...

AI Technical Summary

Problems solved by technology

On the other hand, because some auxiliary drilling tools are often used in drilling operations, including while-drilling jars, shock absorbers, etc., when these tools need to be fished, due to the uncertainty of the inner diameter of the fishing part, the existing fishing tools Often cannot meet the requirements of on-site operations, thereby affecting the efficiency of accident handling

[0005] Now domestic overshots and fishing spears generally have one slip that can only correspond to one size of fish, but the entire drill string has many different sizes, and you can’t predict where it will break. If each size is equipped with a slip, It is often necessary to dispense more than a dozen kinds of slips. Firstly, too many slips are unacceptable to the customer. Second, if the slips are not complete, in case the broken fish does not have the right size, the real time is when the drill string or casing breaks downhole. It is too late to salvage in time, and more serious downhole accidents are likely to occur. Therefore, it is necessary to develop a large-scale fishing tool both from the customer's point of view and from the company's point of view.

Images