Research on drillable bridge plug washing and fishing tools and its application

To solve the problem that the washing efficiency is low in domestic Oilfields by using the conventional bridge plug removal methods, the drillable bridge plug washing and fishing tool and the systematic technologies are developed, as well as the operating procedure of the tool is perfected. The research work consists of the research on the rational design of the slip structure in the fishing tool, the way research on the simultaneous carrying-out of the fluctuation and the rotary motion. In the slip cylinder, the outer taper surface matches with the inner taper surface in the reversible lock sleeve. During normal washing, the slip can fluctuate and rotate in the reversible lock sleeve. The special structure design of the reversible lock sleeve ensures the washing and fishing tools to be lifted safely and completely when the string is plugged. During the washing process, the emphasis should not only be laid on the tool selection and structural design, but also be laid on the optimization of construction parameters and washing hole assembly design. The tool can be used to reduce the drilling times, improve the washing and fishing efficiency of drilling bridge plug, and reduce drilling time and cost.